Search for "indoles" in Full Text gives 229 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Beilstein J. Org. Chem. 2021, 17, 1392–1439, doi:10.3762/bjoc.17.98
Graphical Abstract
Figure 1: Double-headed nucleosides. B1 and B2 = nucleobases or heterocyclic/carbocyclic moieties; L = linker....
Scheme 1: Synthesis of 2′-(pyrimidin-1-yl)methyl- or 2′-(purin-9-yl)methyl-substituted double-headed nucleosi...
Scheme 2: Synthesis of double-headed nucleoside 7 having two cytosine moieties.
Scheme 3: Synthesis of double-headed nucleoside 2′-deoxy-2′-C-(2-(thymine-1-yl)ethyl)-uridine (11).
Scheme 4: Double-headed nucleosides 14 and 15 obtained by click reaction.
Scheme 5: Synthesis of the double-headed nucleoside 19.
Scheme 6: Synthesis of the double-headed nucleosides 24 and 25.
Scheme 7: Synthesis of double-headed nucleosides 28 and 29.
Scheme 8: Synthesis of double-headed nucleoside 33.
Scheme 9: Synthesis of double-headed nucleoside 37.
Scheme 10: Synthesis of the double-headed nucleoside 1-(5′-O-(4,4′-dimethoxytrityl)-2′-C-((4-(pyren-1-yl)-1,2,...
Scheme 11: Synthesis of triazole-containing double-headed ribonucleosides 46a–c and 50a–e.
Scheme 12: Synthesis of double-headed nucleosides 54a–g.
Scheme 13: Synthesis of double-headed nucleosides 59 and 60.
Scheme 14: Synthesis of the double-headed nucleosides 63 and 64.
Scheme 15: Synthesis of double-headed nucleosides 66a–c.
Scheme 16: Synthesis of benzoxazole-containing double-headed nucleosides 69 and 71 from 5′-amino-5′-deoxynucle...
Scheme 17: Synthesis of 4′-C-((N6-benzoyladenin-9-yl)methyl)thymidine (75) and 4′-C-((thymin-1-yl)methyl)thymi...
Scheme 18: Synthesis of double-headed nucleosides 5′-(adenine-9-yl)-5′-deoxythymidine (79) and 5′-(adenine-9-y...
Scheme 19: Synthesis of double-headed nucleosides 85–87 via reversed nucleosides methodology.
Scheme 20: Double-headed nucleosides 91 and 92 derived from ω-terminal-acetylenic sugar derivatives 90a,b.
Scheme 21: Synthesis of double-headed nucleosides 96a–g.
Scheme 22: Synthesis of double-headed nucleosides 100 and 103.
Scheme 23: Double-headed nucleosides 104 and 105 with a triazole motif.
Scheme 24: Synthesis of the double-headed nucleosides 107 and 108.
Scheme 25: Synthesis of double-headed nucleoside 110 with additional nucleobase in 5′-(S)-C-position joined th...
Scheme 26: Synthesis of double-headed nucleosides 111–113 with additional nucleobases in the 5′-(S)-C-position...
Scheme 27: Synthesis of double-headed nucleoside 114 by click reaction.
Scheme 28: Synthesis of double-headed nucleosides 118 with an additional nucleobase at the 5′-(S)-C-position.
Scheme 29: Synthesis of bicyclic double-headed nucleoside 122.
Scheme 30: Synthesis of double-headed nucleosides 125a–c derived from 2′-amino-LNA.
Scheme 31: Double-headed nucleoside 127 obtained by click reaction.
Scheme 32: Synthesis of double-headed nucleoside 130.
Scheme 33: Double-headed nucleosides 132a–d and 134a–d synthesized by Sonogashira cross coupling reaction.
Scheme 34: Synthesis of double-headed nucleosides 137 and 138 via Suzuki coupling.
Scheme 35: Synthesis of double-headed nucleosides 140 and 141 via Sonogashira cross coupling reaction.
Scheme 36: Synthesis of double-headed nucleoside 143.
Scheme 37: Synthesis of the double-headed nucleoside 146.
Scheme 38: Synthesis of 5-C-alkynyl-functionalized double-headed nucleosides 151a–d.
Scheme 39: Synthesis of 5-C-triazolyl-functionalized double-headed nucleosides 154a, b.
Scheme 40: Synthesis of double-headed nucleosides 157a–c.
Scheme 41: Synthesis of double-headed nucleoside 159, phosphoramidite 160 and the corresponding nucleotide mon...
Scheme 42: Synthesis of double-headed nucleoside 163, phosphoramidite 164 and the corresponding nucleotide mon...
Scheme 43: Synthesis of double-headed nucleoside 167, phosphoramidite 168, and the corresponding nucleotide mo...
Scheme 44: Synthesis of double-headed nucleoside 171, phosphoramidite 172, and the corresponding nucleotide mo...
Scheme 45: Synthesis of double-headed nucleoside 175, phosphoramidite 176, and the corresponding nucleotide mo...
Scheme 46: Synthesis of double-headed nucleoside 178.
Scheme 47: Synthesis of the double-headed nucleosides 181 and 183.
Scheme 48: Alternative synthesis of the double-headed nucleoside 183.
Scheme 49: Synthesis of double-headed nucleoside 188 through thermal [2 + 3] sydnone–alkyne cycloaddition reac...
Scheme 50: Synthesis of the double-headed nucleosides 190 and 191.
Scheme 51: Synthesis of 1-((5S)-2,3,4-tri-O-acetyl-5-(2,6-dichloropurin-9-yl)-β-ᴅ-xylopyranosyl)uracil (195).
Scheme 52: Synthesis of hexopyranosyl double-headed pyrimidine homonucleosides 200a–c.
Figure 2: 3′-C-Ethynyl-β-ᴅ-allopyranonucleoside derivatives 201a–f.
Scheme 53: Synthesis of 3′-C-(1,4-disubstituted-1,2,3-triazolyl)-double-headed pyranonucleosides 203–207.
Scheme 54: Synthesis of 3′-C-(1,4-disubstituted-1,2,3-triazolyl)-double-headed pyranonucleosides 208 and 209.
Scheme 55: Synthesis of 3′-C-(1,4-disubstituted-1,2,3-triazolyl)-double-headed pyranonucleoside 210.
Scheme 56: Synthesis of double-headed acyclic nucleosides (2S,3R)-1,4-bis(thymine-1-yl)butane-2,3-diol (213a) ...
Scheme 57: Synthesis of double-headed acyclic nucleosides (2R,3S)-1,4-bis(thymine-1-yl)butane-2,3-diol (213c) ...
Scheme 58: Synthesis of double-headed acetylated 1,3,4-oxadiazino[6,5-b]indolium-substituted C-nucleosides 218b...
Scheme 59: Synthesis of double-headed acyclic nucleoside 222.
Scheme 60: Synthesis of functionalized 1,2-bis(1,2,4-triazol-3-yl)ethane-1,2-diols 223a–f.
Scheme 61: Synthesis of acyclic double-headed 1,2,4-triazino[5,6-b]indole C-nucleosides 226–231.
Scheme 62: Synthesis of double-headed 1,3,4-thiadiazoline, 1,3,4-oxadiazoline, and 1,2,4-triazoline acyclo C-n...
Scheme 63: Synthesis of double-headed acyclo C-nucleosides 240–242.
Scheme 64: Synthesis of double-headed acyclo C-nucleoside 246.
Scheme 65: Synthesis of acyclo double-headed nucleoside 250.
Scheme 66: Synthesis of acyclo double-headed nucleoside 253.
Scheme 67: Synthesis of acyclo double-headed nucleosides 259a–d.
Scheme 68: Synthesis of acyclo double-headed nucleoside 261.
Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90
Graphical Abstract
Figure 1: Representative shares of the global F&F market (2018) segmented on their applications [1].
Figure 2: General structure of an international fragrance company [2].
Figure 3: The Michael Edwards fragrance wheel.
Figure 4: Examples of oriental (1–3), woody (4–7), fresh (8–10), and floral (11 and 12) notes.
Figure 5: A basic depiction of batch vs flow.
Scheme 1: Examples of reactions for which flow processing outperforms batch.
Scheme 2: Some industrially important aldol-based transformations.
Scheme 3: Biphasic continuous aldol reactions of acetone and various aldehydes.
Scheme 4: Aldol synthesis of 43 in flow using LiHMDS as the base.
Scheme 5: A semi-continuous synthesis of doravirine (49) involving a key aldol reaction.
Scheme 6: Enantioselective aldol reaction using 5-(pyrrolidin-2-yl)tetrazole (51) as catalyst in a microreact...
Scheme 7: Gröger's example of asymmetric aldol reaction in aqueous media.
Figure 6: Immobilised reagent column reactor types.
Scheme 8: Photoinduced thiol–ene coupling preparation of silica-supported 5-(pyrrolidin-2-yl)tetrazole 63 and...
Scheme 9: Continuous-flow approach for enantioselective aldol reactions using the supported catalyst 67.
Scheme 10: Ötvös’ employment of a solid-supported peptide aldol catalyst in flow.
Scheme 11: The use of proline tetrazole packed in a column for aldol reaction between cyclohexanone (65) and 2...
Scheme 12: Schematic diagram of an aminosilane-grafted Si-Zr-Ti/PAI-HF reactor for continuous-flow aldol and n...
Scheme 13: Continuous-flow condensation for the synthesis of the intermediate 76 to nabumetone (77) and Microi...
Scheme 14: Synthesis of ψ-Ionone (80) in continuous-flow via aldol condensation between citral (79) and aceton...
Scheme 15: Synthesis of β-methyl-ionones (83) from citral (79) in flow. The steps are separately described, an...
Scheme 16: Continuous-flow synthesis of 85 from 84 described by Gavriilidis et al.
Scheme 17: Continuous-flow scCO2 apparatus for the synthesis of 2-methylpentanal (87) and the self-condensed u...
Scheme 18: Chen’s two-step flow synthesis of coumarin (90).
Scheme 19: Pechmann condensation for the synthesis of 7-hydroxyxcoumarin (93) in flow. The setup extended to c...
Scheme 20: Synthesis of the dihydrojasmonate 35 exploiting nitro derivative proposed by Ballini et al.
Scheme 21: Silica-supported amines as heterogeneous catalyst for nitroaldol condensation in flow.
Scheme 22: Flow apparatus for the nitroaldol condensation of p-hydroxybenzaldehyde (102) to nitrostyrene 103 a...
Scheme 23: Nitroaldol reaction of 64 to 105 employing a quaternary ammonium functionalised PANF.
Scheme 24: Enantioselective nitroaldol condensation for the synthesis of 108 under flow conditions.
Scheme 25: Enatioselective synthesis of 1,2-aminoalcohol 110 via a copper-catalysed nitroaldol condensation.
Scheme 26: Examples of Knoevenagel condensations applied for fragrance components.
Scheme 27: Flow apparatus for Knoevenagel condensation described in 1989 by Venturello et al.
Scheme 28: Knoevenagel reaction using a coated multichannel membrane microreactor.
Scheme 29: Continuous-flow apparatus for Knoevenagel condensation employing sugar cane bagasse as support deve...
Scheme 30: Knoevenagel reaction for the synthesis of 131–135 in flow using an amine-functionalised silica gel. ...
Scheme 31: Continuous-flow synthesis of compound 137, a key intermediate for the synthesis of pregabalin (138)...
Scheme 32: Continuous solvent-free apparatus applied for the synthesis of compounds 140–143 using a TSE. Throu...
Scheme 33: Lewis et al. developed a spinning disc reactor for Darzens condensation of 144 and a ketone to furn...
Scheme 34: Some key industrial applications of conjugate additions in the F&F industry.
Scheme 35: Continuous-flow synthesis of 4-(2-hydroxyethyl)thiomorpholine 1,1-dioxide (156) via double conjugat...
Scheme 36: Continuous-flow system for Michael addition using CsF on alumina as the catalyst.
Scheme 37: Calcium chloride-catalysed asymmetric Michael addition using an immobilised chiral ligand.
Scheme 38: Continuous multistep synthesis for the preparation of (R)-rolipram (173). Si-NH2: primary amine-fun...
Scheme 39: Continuous-flow Michael addition using ion exchange resin Amberlyst® A26.
Scheme 40: Preparation of the heterogeneous catalyst 181 developed by Paixão et al. exploiting Ugi multicompon...
Scheme 41: Continuous-flow system developed by the Paixão’s group for the preparation of Michael asymmetric ad...
Scheme 42: Continuous-flow synthesis of nitroaldols catalysed by supported catalyst 184 developed by Wennemers...
Scheme 43: Heterogenous polystyrene-supported catalysts developed by Pericàs and co-workers.
Scheme 44: PANF-supported pyrrolidine catalyst for the conjugate addition of cyclohexanone (65) and trans-β-ni...
Scheme 45: Synthesis of (−)-paroxetine precursor 195 developed by Ötvös, Pericàs, and Kappe.
Scheme 46: Continuous-flow approach for the 5-step synthesis of (−)-oseltamivir (201) as devised by Hayashi an...
Scheme 47: Continuous-flow enzyme-catalysed Michael addition.
Scheme 48: Continuous-flow copper-catalysed 1,4 conjugate addition of Grignard reagents to enones. Reprinted w...
Scheme 49: A collection of commonly encountered hydrogenation reactions.
Figure 7: The ThalesNano H-Cube® continuous-flow hydrogenator.
Scheme 50: Chemoselective reduction of an α,β-unsaturated ketone using the H-Cube® reactor.
Scheme 51: Incorporation of Lindlar’s catalyst into the H-Cube® reactor for the reduction of an alkyne.
Scheme 52: Continuous-flow semi-hydrogenation of alkyne 208 to 209 using SACs with H-Cube® system.
Figure 8: The standard setups for tube-in-tube gas–liquid reactor units.
Scheme 53: Homogeneous hydrogenation of olefins using a tube-in-tube reactor setup.
Scheme 54: Recyclable heterogeneous flow hydrogenation system.
Scheme 55: Leadbeater’s reverse tube-in-tube hydrogenation system for olefin reductions.
Scheme 56: a) Hydrogenation using a Pd-immobilised microchannel reactor (MCR) and b) a representation of the i...
Scheme 57: Hydrogenation of alkyne 238 exploiting segmented flow in a Pd-immobilised capillary reactor.
Scheme 58: Continuous hydrogenation system for the preparation of cyrene (241) from (−)-levoglucosenone (240).
Scheme 59: Continuous hydrogenation system based on CSMs developed by Hornung et al.
Scheme 60: Chemoselective reduction of carbonyls (ketones over aldehydes) in flow.
Scheme 61: Continuous system for the semi-hydrogenation of 256 and 258, developed by Galarneau et al.
Scheme 62: Continuous synthesis of biodiesel fuel 261 from lignin-derived furfural acetone (260).
Scheme 63: Continuous synthesis of γ-valerolacetone (263) via CTH developed by Pineda et al.
Scheme 64: Continuous hydrogenation of lignin-derived biomass (products 265, 266, and 267) using a sustainable...
Scheme 65: Ru/C or Rh/C-catalysed hydrogenation of arene in flow as developed by Sajiki et al.
Scheme 66: Polysilane-immobilized Rh–Pt-catalysed hydrogenation of arenes in flow by Kobayashi et al.
Scheme 67: High-pressure in-line mixing of H2 for the asymmetric reduction of 278 at pilot scale with a 73 L p...
Figure 9: Picture of the PFR employed at Eli Lilly & Co. for the continuous hydrogenation of 278 [287]. Reprinted ...
Scheme 68: Continuous-flow asymmetric hydrogenation using Oppolzer's sultam 280 as chiral auxiliary.
Scheme 69: Some examples of industrially important oxidation reactions in the F&F industry. CFL: compact fluor...
Scheme 70: Gold-catalysed heterogeneous oxidation of alcohols in flow.
Scheme 71: Uozumi’s ARP-Pt flow oxidation protocol.
Scheme 72: High-throughput screening of aldehyde oxidation in flow using an in-line GC.
Scheme 73: Permanganate-mediated Nef oxidation of nitroalkanes in flow with the use of in-line sonication to p...
Scheme 74: Continuous-flow aerobic anti-Markovnikov Wacker oxidation.
Scheme 75: Continuous-flow oxidation of 2-benzylpyridine (312) using air as the oxidant.
Scheme 76: Continuous-flow photo-oxygenation of monoterpenes.
Scheme 77: A tubular reactor design for flow photo-oxygenation.
Scheme 78: Glucose oxidase (GOx)-mediated continuous oxidation of glucose using compressed air and the FFMR re...
Scheme 79: Schematic continuous-flow sodium hypochlorite/TEMPO oxidation of alcohols.
Scheme 80: Oxidation using immobilised TEMPO (344) was developed by McQuade et al.
Scheme 81: General protocol for the bleach/catalytic TBAB oxidation of aldehydes and alcohols.
Scheme 82: Continuous-flow PTC-assisted oxidation using hydrogen peroxide. The process was easily scaled up by...
Scheme 83: Continuous-flow epoxidation of cyclohexene (348) and in situ preparation of m-CPBA.
Scheme 84: Continuous-flow epoxidation using DMDO as oxidant.
Scheme 85: Mukayama aerobic epoxidation optimised in flow mode by the Favre-Réguillon group.
Scheme 86: Continuous-flow asymmetric epoxidation of derivatives of 359 exploiting a biomimetic iron catalyst.
Scheme 87: Continuous-flow enzymatic epoxidation of alkenes developed by Watts et al.
Scheme 88: Engineered multichannel microreactor for continuous-flow ozonolysis of 366.
Scheme 89: Continuous-flow synthesis of the vitamin D precursor 368 using multichannel microreactors. MFC: mas...
Scheme 90: Continuous ozonolysis setup used by Kappe et al. for the synthesis of various substrates employing ...
Scheme 91: Continuous-flow apparatus for ozonolysis as developed by Ley et al.
Scheme 92: Continuous-flow ozonolysis for synthesis of vanillin (2) using a film-shear flow reactor.
Scheme 93: Examples of preparative methods for ajoene (386) and allicin (388).
Scheme 94: Continuous-flow oxidation of thioanisole (389) using styrene-based polymer-supported peroxytungstat...
Scheme 95: Continuous oxidation of thiosulfinates using Oxone®-packed reactor.
Scheme 96: Continuous-flow electrochemical oxidation of thioethers.
Scheme 97: Continuous-flow oxidation of 400 to cinnamophenone (235).
Scheme 98: Continuous-flow synthesis of dehydrated material 401 via oxidation of methyl dihydrojasmonate (33).
Scheme 99: Some industrially important transformations involving Grignard reagents.
Scheme 100: Grachev et al. apparatus for continuous preparation of Grignard reagents.
Scheme 101: Example of fluidized Mg bed reactor with NMR spectrometer as on-line monitoring system.
Scheme 102: Continuous-flow synthesis of Grignard reagents and subsequent quenching reaction.
Figure 10: Membrane-based, liquid–liquid separator with integrated pressure control [52]. Adapted with permission ...
Scheme 103: Continuous-flow synthesis of 458, an intermediate to fluconazole (459).
Scheme 104: Continuous-flow synthesis of ketones starting from benzoyl chlorides.
Scheme 105: A Grignard alkylation combining CSTR and PFR technologies with in-line infrared reaction monitoring....
Scheme 106: Continuous-flow preparation of 469 from Grignard addition of methylmagnesium bromide.
Scheme 107: Continuous-flow synthesis of Grignard reagents 471.
Scheme 108: Preparation of the Grignard reagent 471 using CSTR and the continuous process for synthesis of the ...
Scheme 109: Continuous process for carboxylation of Grignard reagents in flow using tube-in-tube technology.
Scheme 110: Continuous synthesis of propargylic alcohols via ethynyl-Grignard reagent.
Scheme 111: Silica-supported catalysed enantioselective arylation of aldehydes using Grignard reagents in flow ...
Scheme 112: Acid-catalysed rearrangement of citral and dehydrolinalool derivatives.
Scheme 113: Continuous stilbene isomerisation with continuous recycling of photoredox catalyst.
Scheme 114: Continuous-flow synthesis of compound 494 as developed by Ley et al.
Scheme 115: Selected industrial applications of DA reaction.
Scheme 116: Multistep flow synthesis of the spirocyclic structure 505 via employing DA cycloaddition.
Scheme 117: Continuous-flow DA reaction developed in a plater flow reactor for the preparation of the adduct 508...
Scheme 118: Continuous-flow DA reaction using a silica-supported imidazolidinone organocatalyst.
Scheme 119: Batch vs flow for the DA reaction of (cyclohexa-1,5-dien-1-yloxy)trimethylsilane (513) with acrylon...
Scheme 120: Continuous-flow DA reaction between 510 and 515 using a shell-core droplet system.
Scheme 121: Continuous-flow synthesis of bicyclic systems from benzyne precursors.
Scheme 122: Continuous-flow synthesis of bicyclic scaffolds 527 and 528 for further development of potential ph...
Scheme 123: Continuous-flow inverse-electron hetero-DA reaction to pyridine derivatives such as 531.
Scheme 124: Comparison between batch and flow for the synthesis of pyrimidinones 532–536 via retro-DA reaction ...
Scheme 125: Continuous-flow coupled with ultrasonic system for preparation of ʟ-ascorbic acid derivatives 539 d...
Scheme 126: Two-step continuous-flow synthesis of triazole 543.
Scheme 127: Continuous-flow preparation of triazoles via CuAAC employing 546-based heterogeneous catalyst.
Scheme 128: Continuous-flow synthesis of compounds 558 through A3-coupling and 560 via AgAAC both employing the...
Scheme 129: Continuous-flow photoinduced [2 + 2] cycloaddition for the preparation of bicyclic derivatives of 5...
Scheme 130: Continuous-flow [2 + 2] and [5 + 2] cycloaddition on large scale employing a flow reactor developed...
Scheme 131: Continuous-flow preparation of the tricyclic structures 573 and 574 starting from pyrrole 570 via [...
Scheme 132: Continuous-flow [2 + 2] photocyclization of cinnamates.
Scheme 133: Continuous-flow preparation of cyclobutane 580 on a 5-plates photoreactor.
Scheme 134: Continuous-flow [2 + 2] photocycloaddition under white LED lamp using heterogeneous PCN as photocat...
Figure 11: Picture of the parallel tube flow reactor (PTFR) "The Firefly" developed by Booker-Milburn et al. a...
Scheme 135: Continuous-flow acid-catalysed [2 + 2] cycloaddition between silyl enol ethers and acrylic esters.
Scheme 136: Continuous synthesis of lactam 602 using glass column reactors.
Scheme 137: In situ generation of ketenes for the Staudinger lactam synthesis developed by Ley and Hafner.
Scheme 138: Application of [2 + 2 + 2] cycloadditions in flow employed by Ley et al.
Scheme 139: Examples of FC reactions applied in F&F industry.
Scheme 140: Continuous-flow synthesis of ibuprofen developed by McQuade et al.
Scheme 141: The FC acylation step of Jamison’s three-step ibuprofen synthesis.
Scheme 142: Synthesis of naphthalene derivative 629 via FC acylation in microreactors.
Scheme 143: Flow system for rapid screening of catalysts and reaction conditions developed by Weber et al.
Scheme 144: Continuous-flow system developed by Buorne, Muller et al. for DSD optimisation of the FC acylation ...
Scheme 145: Continuous-flow FC acylation of alkynes to yield β-chlorovinyl ketones such as 638.
Scheme 146: Continuous-flow synthesis of tonalide (619) developed by Wang et al.
Scheme 147: Continuous-flow preparation of acylated arene such as 290 employing Zr4+-β-zeolite developed by Kob...
Scheme 148: Flow system applied on an Aza-FC reaction catalysed by the thiourea catalyst 648.
Scheme 149: Continuous hydroformylation in scCO2.
Scheme 150: Two-step flow synthesis of aldehyde 655 through a sequential Heck reaction and subsequent hydroform...
Scheme 151: Single-droplet (above) and continuous (below) flow reactors developed by Abolhasani et al. for the ...
Scheme 152: Continuous hydroformylation of 1-dodecene (655) using a PFR-CSTR system developed by Sundmacher et ...
Scheme 153: Continuous-flow synthesis of the aldehyde 660 developed by Eli Lilly & Co. [32]. Adapted with permissio...
Scheme 154: Continuous asymmetric hydroformylation employing heterogenous catalst supported on carbon-based sup...
Scheme 155: Examples of acetylation in F&F industry: synthesis of bornyl (S,R,S-664) and isobornyl (S,S,S-664) ...
Scheme 156: Continuous-flow preparation of bornyl acetate (S,R,S-664) employing the oscillating flow reactor.
Scheme 157: Continuous-flow synthesis of geranyl acetate (666) from acetylation of geraniol (343) developed by ...
Scheme 158: 12-Ttungstosilicic acid-supported silica monolith-catalysed acetylation in flow.
Scheme 159: Continuous-flow preparation of cyclopentenone 676.
Scheme 160: Two-stage synthesis of coumarin (90) via acetylation of salicylaldehyde (88).
Scheme 161: Intensification process for acetylation of 5-methoxytryptamine (677) to melatonin (678) developed b...
Scheme 162: Examples of macrocyclic musky odorants both natural (679–681) and synthetic (682 and 683).
Scheme 163: Flow setup combined with microwave for the synthesis of macrocycle 686 via RCM.
Scheme 164: Continuous synthesis of 2,5-dihydro-1H-pyrroles via ring-closing metathesis.
Scheme 165: Continuous-flow metathesis of 485 developed by Leadbeater et al.
Figure 12: Comparison between RCM performed using different routes for the preparation of 696. On the left the...
Scheme 166: Continuous-flow RCM of 697 employed the solid-supported catalyst 698 developed by Grela, Kirschning...
Scheme 167: Continuous-flow RORCM of cyclooctene employing the silica-absorbed catalyst 700.
Scheme 168: Continuous-flow self-metathesis of methyl oleate (703) employing SILP catalyst 704.
Scheme 169: Flow apparatus for the RCM of 697 using a nanofiltration membrane for the recovery and reuse of the...
Scheme 170: Comparison of loadings between RCMs performed with different routes for the synthesis of 709.
Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86
Graphical Abstract
Scheme 1: General strategy for the enantioselective synthesis of N-containing heterocycles from N-tert-butane...
Scheme 2: Methodologies for condensation of aldehydes and ketones with tert-butanesulfinamides (1).
Scheme 3: Transition models for cis-aziridines and trans-aziridines.
Scheme 4: Mechanism for the reduction of N-tert-butanesulfinyl imines.
Scheme 5: Transition models for the addition of organomagnesium and organolithium compounds to N-tert-butanes...
Scheme 6: Synthesis of 2,2-dibromoaziridines 15 from aldimines 14 and bromoform, and proposed non-chelation-c...
Scheme 7: Diastereoselective synthesis of aziridines from tert-butanesulfinyl imines.
Scheme 8: Synthesis of vinylaziridines 22 from aldimines 14 and 1,3-dibromopropene 23, and proposed chelation...
Scheme 9: Synthesis of vinylaziridines 27 from aldimines 14 and α-bromoesters 26, and proposed transition sta...
Scheme 10: Synthesis of 2-chloroaziridines 28 from aldimines 14 and dichloromethane, and proposed transition s...
Scheme 11: Synthesis of cis-vinylaziridines 30 and 31 from aldimines 14 and bromomethylbutenolide 29.
Scheme 12: Synthesis of 2-chloro-2-aroylaziridines 36 and 32 from aldimines 14, arylnitriles 34, and silyldich...
Scheme 13: Synthesis of trifluoromethylaziridines 39 and proposed transition state of the aziridination.
Scheme 14: Synthesis of aziridines 42 and proposed state transition.
Scheme 15: Synthesis of 1-substituted 2-azaspiro[3.3]heptanes, 1-phenyl-2-azaspiro[3.4]octane and 1-phenyl-2-a...
Scheme 16: Synthesis of 1-substituted 2,6-diazaspiro[3.3]heptanes 48 from chiral imines 14 and 1-Boc-azetidine...
Scheme 17: Synthesis of β-lactams 52 from chiral imines 14 and dimethyl malonate (49).
Scheme 18: Synthesis of spiro-β-lactam 57 from chiral (RS)-N-tert-butanesulfinyl isatin ketimine 53 and ethyl ...
Scheme 19: Synthesis of β-lactam 60, a precursor of (−)-batzelladine D (61) and (−)-13-epi-batzelladine D (62)...
Scheme 20: Rhodium-catalyzed asymmetric synthesis of 3-substituted pyrrolidines 66 from chiral imine (RS)-63 a...
Scheme 21: Asymmetric synthesis of 1,3-disubstituted isoindolines 69 and 70 from chiral imine 67.
Scheme 22: Asymmetric synthesis of cis-2,5-disubstituted pyrrolidines 73 from chiral imine (RS)-71.
Scheme 23: Asymmetric synthesis of 3-hydroxy-5-substituted pyrrolidin-2-ones 77 from chiral imine (RS)-74.
Scheme 24: Asymmetric synthesis of 4-hydroxy-5-substituted pyrrolidin-2-ones 80 from chiral imines 79.
Scheme 25: Asymmetric synthesis of 3-pyrrolines 82 from chiral imines 14 and ethyl 4-bromocrotonate (81).
Scheme 26: Asymmetric synthesis of γ-amino esters 84, and tetramic acid derivative 86 from chiral imines (RS)-...
Scheme 27: Asymmetric synthesis of α-methylene-γ-butyrolactams 90 from chiral imines (Z,SS)-87 and ethyl 2-bro...
Scheme 28: Asymmetric synthesis of methylenepyrrolidines 92 from chiral imines (RS)-14 and 2-(trimethysilylmet...
Scheme 29: Synthesis of dibenzoazaspirodecanes from cyclic N-tert-butanesulfinyl imines.
Scheme 30: Stereoselective synthesis of cyclopenta[c]proline derivatives 103 from β,γ-unsaturated α-amino acid...
Scheme 31: Stereoselective synthesis of alkaloids (−)-angustureine (107) and (−)-cuspareine (108).
Scheme 32: Stereoselective synthesis of alkaloids (−)-pelletierine (112) and (+)-coniine (117).
Scheme 33: Synthesis of piperidine alkaloids (+)-dihydropinidine (122a), (+)-isosolenopsin (122b) and (+)-isos...
Scheme 34: Stereoselective synthesis of the alkaloids(+)-sedamine (125) from chiral imine (SS)-119.
Scheme 35: Stereoselective synthesis of trans-5-hydroxy-6-substituted-2-piperidinones 127 and 129 from chiral ...
Scheme 36: Stereoselective synthesis of trans-5-hydroxy-6-substituted ethanone-2-piperidinones 132 from chiral...
Scheme 37: Stereoselective synthesis of trans-3-benzyl-5-hydroxy-6-substituted-2-piperidinones 136 from chiral...
Scheme 38: Stereoselective synthesis of trans-5-hydroxy-6-substituted 2-piperidinones 139 from chiral imine 138...
Scheme 39: Stereoselective synthesis of ʟ-hydroxypipecolic acid 145 from chiral imine 144.
Scheme 40: Synthesis of 1-substituted isoquinolones 147, 149 and 151.
Scheme 41: Stereoselective synthesis of 3-substituted dihydrobenzo[de]isoquinolinones 154.
Scheme 42: Enantioselective synthesis of alkaloids (S)-1-benzyl-6,7-dimethoxy-1,2,3,4-tetrahydroisoquinoline (...
Scheme 43: Enantioselective synthesis of alkaloids (−)-cermizine B (171) and (+)-serratezomine E (172) develop...
Scheme 44: Stereoselective synthesis of (+)-isosolepnosin (177) and (+)-solepnosin (178) from homoallylamine d...
Scheme 45: Stereoselective synthesis of tetrahydroquinoline derivatives 184, 185 and 187 from chiral imines (RS...
Scheme 46: Stereoselective synthesis of pyridobenzofuran and pyridoindole derivatives 193 from homopropargylam...
Scheme 47: Stereoselective synthesis of 2-substituted 1,2,5,6-tetrahydropyridines 196 from chiral imines (RS)-...
Scheme 48: Stereoselective synthesis of 2-substituted trans-2,6-disubstituted piperidine 199 from chiral imine...
Scheme 49: Stereoselective synthesis of cis-2,6-disubstituted piperidines 200, and alkaloid (+)-241D, from chi...
Scheme 50: Stereoselective synthesis of 6-substituted piperidines-2,5-diones 206 and 1,7-diazaspiro[4.5]decane...
Scheme 51: Stereoselective synthesis of spirocyclic oxindoles 210 from chiral imines (RS)-53.
Scheme 52: Stereoselective synthesis of azaspiro compound 213 from chiral imine 211.
Scheme 53: Stereoselective synthesis of tetrahydroisoquinoline derivatives from chiral imines (RS)-214.
Scheme 54: Stereoselective synthesis of (−)-crispine A 223 from chiral imine (RS)-214.
Scheme 55: Synthesis of (−)-harmicine (228) using tert-butanesulfinamide through haloamide cyclization.
Scheme 56: Stereoselective synthesis of tetraponerines T1–T8.
Scheme 57: Stereoselective synthesis of phenanthroindolizidines 246a and (−)-tylophorine (246b), and phenanthr...
Scheme 58: Stereoselective synthesis of indoline, tetrahydroquinoline and tetrahydrobenzazepine derivatives 253...
Scheme 59: Stereoselective synthesis of (+)-epohelmin A (258) and (+)-epohelmin B (260) from aldimine (RS)-79.
Scheme 60: Stereoselective synthesis of (−)-epiquinamide (266) from chiral aldimine (SS)-261.
Scheme 61: Synthesis synthesis of (–)-hippodamine (273) and (+)-epi-hippodamine (272) using chiral sulfinyl am...
Scheme 62: Stereoselective synthesis of (+)-grandisine D (279) and (+)-amabiline (283).
Scheme 63: Stereoselective synthesis of (−)-epiquinamide (266) and (+)-swaisonine (291) from aldimine (SS)-126....
Scheme 64: Stereoselective synthesis of (+)-C(9a)-epi-epiquinamide (294).
Scheme 65: Stereoselective synthesis of (+)-lasubine II (298) from chiral aldimine (SS)-109.
Scheme 66: Stereoselective synthesis of (−)-epimyrtine (300a) and (−)-lasubine II (ent-302) from β-amino keton...
Scheme 67: Stereoselective synthesis of (−)-tabersonine (310), (−)-vincadifformine (311), and (−)-aspidospermi...
Scheme 68: Stereoselective synthesis of (+)-epohelmin A (258) and (+)-epohelmin B (260) from aldehyde 313 and ...
Scheme 69: Total synthesis of (+)-lysergic acid (323) from N-tert-butanesulfinamide (RS)-1.
Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71
Graphical Abstract
Figure 1: Marketed drugs with acridine moiety.
Scheme 1: Synthesis of 4-arylacridinediones.
Scheme 2: Proposed mechanism for acridinedione synthesis.
Scheme 3: Synthesis of tetrahydrodibenzoacridinones.
Scheme 4: Synthesis of naphthoacridines.
Scheme 5: Plausible mechanism for naphthoacridines.
Figure 2: Benzoazepines based potent molecules.
Scheme 6: Synthesis of azepinone.
Scheme 7: Proposed mechanism for azepinone formation.
Scheme 8: Synthesis of benzoazulenen-1-one derivatives.
Scheme 9: Proposed mechanism for benzoazulene-1-one synthesis.
Figure 3: Indole-containing pharmacologically active molecules.
Scheme 10: Synthesis of functionalized indoles.
Scheme 11: Plausible mechanism for the synthesis of functionalized indoles.
Scheme 12: Synthesis of spirooxindoles.
Scheme 13: Synthesis of substituted spirooxindoles.
Scheme 14: Plausible mechanism for the synthesis of substituted spirooxindoles.
Scheme 15: Synthesis of pyrrolidinyl spirooxindoles.
Scheme 16: Proposed mechanism for pyrrolidinyl spirooxindoles.
Figure 4: Pyran-containing biologically active molecules.
Scheme 17: Synthesis of functionalized benzopyrans.
Scheme 18: Plausible mechanism for synthesis of benzopyran.
Scheme 19: Synthesis of indoline-spiro-fused pyran derivatives.
Scheme 20: Proposed mechanism for indoline-spiro-fused pyran.
Scheme 21: Synthesis of substituted naphthopyrans.
Figure 5: Marketed drugs with pyrrole ring.
Scheme 22: Synthesis of tetra-substituted pyrroles.
Scheme 23: Mechanism for silica-supported PPA-SiO2-catalyzed pyrrole synthesis.
Scheme 24: Synthesis of pyrrolo[1,10]-phenanthrolines.
Scheme 25: Proposed mechanism for pyrrolo[1,10]-phenanthrolines.
Figure 6: Marketed drugs and molecules containing pyrimidine and pyrimidinones skeletons.
Scheme 26: MWA-MCR pyrimidinone synthesis.
Scheme 27: Two proposed mechanisms for pyrimidinone synthesis.
Scheme 28: MWA multicomponent synthesis of dihydropyrimidinones.
Scheme 29: Proposed mechanism for dihydropyrimidinones.
Figure 7: Biologically active fused pyrimidines.
Scheme 30: MWA- MCR for the synthesis of pyrrolo[2,3-d]pyrimidines.
Scheme 31: Proposed mechanism for pyrrolo[2,3-d]pyrimidines.
Scheme 32: Synthesis of substituted pyrrolo[2,3-d]pyrimidine-2,4-diones.
Scheme 33: Probable pathway for pyrrolo[2,3-d]pyrimidine-2,4-diones.
Scheme 34: Synthesis of pyridopyrimidines.
Scheme 35: Plausible mechanism for the synthesis of pyridopyrimidines.
Scheme 36: Synthesis of dihydropyridopyrimidine and dihydropyrazolopyridine.
Scheme 37: Proposed mechanism for the formation of dihydropyridopyrimidine.
Scheme 38: Synthesis of thiopyrano[4,3-d]pyrimidines.
Scheme 39: Plausible mechanism for the synthesis of thiopyrano[4,3-d]pyrimidines.
Scheme 40: Synthesis of decorated imidazopyrimidines.
Scheme 41: Proposed mechanism for imidazopyrimidine synthesis.
Figure 8: Pharmacologically active molecules containing purine bases.
Scheme 42: Synthesis of aza-adenines.
Scheme 43: Synthesis of 5-aza-7-deazapurines.
Scheme 44: Proposed mechanism for deazapurines synthesis.
Figure 9: Biologically active molecules containing pyridine moiety.
Scheme 45: Synthesis of steroidal pyridines.
Scheme 46: Proposed mechanism for steroidal pyridine.
Scheme 47: Synthesis of N-alkylated 2-pyridones.
Scheme 48: Two possible mechanisms for pyridone synthesis.
Scheme 49: Synthesis of pyridone derivatives.
Scheme 50: Postulated mechanism for synthesis of pyridone.
Figure 10: Biologically active fused pyridines.
Scheme 51: Benzimidazole-imidazo[1,2-a]pyridines synthesis.
Scheme 52: Mechanism for the synthesis of benzimidazole-imidazo[1,2-a]pyridines.
Scheme 53: Synthesis of pyrazolo[3,4-b]pyridine-5-spirocycloalkanedione derivatives.
Scheme 54: Proposed mechanism for spiro-pyridines.
Scheme 55: Functionalized macrocyclane-fused pyrazolo[3,4-b]pyridine derivatives.
Scheme 56: Mechanism postulated for macrocyclane-fused pyrazolo[3,4-b]pyridine.
Scheme 57: Generation of pyrazolo[3,4-b]pyridines.
Scheme 58: Proposed mechanism for the synthesis of pyrazolo[3,4-b]pyridines.
Scheme 59: Proposed mechanism for the synthesis of azepinoindole.
Figure 11: Pharmaceutically important molecules with quinoline moiety.
Scheme 60: Povarov-mediated quinoline synthesis.
Scheme 61: Proposed mechanism for Povarov reaction.
Scheme 62: Synthesis of pyrazoloquinoline.
Scheme 63: Plausible mechanism for pyrazoloquinoline synthesis.
Figure 12: Quinazolinones as pharmacologically significant scaffolds.
Scheme 64: Four-component reaction for dihydroquinazolinone.
Scheme 65: Proposed mechanism for dihydroquinazolinones.
Scheme 66: Synthesis purine quinazolinone and PI3K-δ inhibitor.
Scheme 67: Synthesis of fused benzothiazolo/benzoimidazoloquinazolinones.
Scheme 68: Proposed mechanism for fused benzothiazolo/benzoimidazoloquinazolinones.
Scheme 69: On-water reaction for synthesis of thiazoloquinazolinone.
Scheme 70: Proposed mechanism for the thiazoloquinazolinone synthesis.
Scheme 71: β-Cyclodextrin-mediated synthesis of indoloquinazolinediones.
Scheme 72: Proposed mechanism for synthesis of indoloquinazolinediones.
Figure 13: Triazoles-containing marketted drugs and pharmacologically active molecules.
Scheme 73: Cu(I) DAPTA-catalyzed 1,2,3-triazole formation.
Scheme 74: Mechanism for Cu(I) DAPTA-catalyzed triazole formation.
Scheme 75: Synthesis of β-hydroxy-1,2,3-triazole.
Scheme 76: Proposed mechanism for synthesis of β-hydroxy-1,2,3-triazoles.
Scheme 77: Synthesis of bis-1,2,4-triazoles.
Scheme 78: Proposed mechanism for bis-1,2,4-triazoles synthesis.
Figure 14: Thiazole containing drugs.
Scheme 79: Synthesis of a substituted thiazole ring.
Scheme 80: Synthesis of pyrazolothiazoles.
Figure 15: Chromene containing drugs.
Scheme 81: Magnetic nanocatalyst-mediated aminochromene synthesis.
Scheme 82: Proposed mechanism for the synthesis of chromenes.
Beilstein J. Org. Chem. 2021, 17, 771–799, doi:10.3762/bjoc.17.67
Graphical Abstract
Scheme 1: The electron transfer process in EDA complexes.
Scheme 2: Synthesis of benzo[b]phosphorus oxide 3 initiated by an EDA complex.
Scheme 3: Mechanism of the synthesis of quinoxaline derivative 7.
Scheme 4: Synthesis of imidazole derivative 10 initiated by an EDA complex.
Scheme 5: Synthesis of sulfamoylation product 12 initiated by an EDA complex.
Scheme 6: Mechanism of the synthesis of sulfamoylation product 12.
Scheme 7: Synthesis of indole derivative 22 initiated by an EDA complex.
Scheme 8: Synthesis of perfluoroalkylated pyrimidines 26 initiated by an EDA complex.
Scheme 9: Synthesis of phenanthridine derivative 29 initiated by an EDA complex.
Scheme 10: Synthesis of cis-tetrahydroquinoline derivative 32 initiated by an EDA complex.
Scheme 11: Mechanism of the synthesis of cis-tetrahydroquinoline derivative 32.
Scheme 12: Synthesis of phenanthridine derivative 38 initiated by an EDA complex.
Scheme 13: Synthesis of spiropyrroline derivative 40 initiated by an EDA complex.
Scheme 14: Synthesis of benzothiazole derivative 43 initiated by an EDA complex.
Scheme 15: Synthesis of perfluoroalkyl-s-triazine derivative 45 initiated by an EDA complex.
Scheme 16: Synthesis of indoline derivative 47 initiated by an EDA complex.
Scheme 17: Mechanism of the synthesis of spirocyclic indoline derivative 47.
Scheme 18: Synthesis of cyclobutane product 50 initiated by an EDA complex.
Scheme 19: Mechanism of the synthesis of spirocyclic indoline derivative 50.
Scheme 20: Synthesis of 1,3-oxazolidine compound 59 initiated by an EDA complex.
Scheme 21: Synthesis of trifluoromethylated product 61 initiated by an EDA complex.
Scheme 22: Synthesis of indole alkylation product 64 initiated by an EDA complex.
Scheme 23: Synthesis of perfluoroalkylation product 67 initiated by an EDA complex.
Scheme 24: Synthesis of hydrotrifluoromethylated product 70 initiated by an EDA complex.
Scheme 25: Synthesis of β-trifluoromethylated alkyne product 71 initiated by an EDA complex.
Scheme 26: Mechanism of the synthesis of 2-phenylthiophene derivative 74.
Scheme 27: Synthesis of allylated product 80 initiated by an EDA complex.
Scheme 28: Synthesis of trifluoromethyl-substituted alkynyl product 84 initiated by an EDA complex.
Scheme 29: Synthesis of dearomatized fluoroalkylation product 86 initiated by an EDA complex.
Scheme 30: Mechanism of the synthesis of dearomatized fluoroalkylation product 86.
Scheme 31: Synthesis of C(sp3)–H allylation product 91 initiated by an EDA complex.
Scheme 32: Synthesis of perfluoroalkylation product 93 initiated by an EDA complex.
Scheme 33: Synthesis of spirocyclic indolene derivative 95 initiated by an EDA complex.
Scheme 34: Synthesis of perfluoroalkylation product 97 initiated by an EDA complex.
Scheme 35: Synthesis of alkylated indole derivative 100 initiated by an EDA complex.
Scheme 36: Mechanism of the synthesis of alkylated indole derivative 100.
Scheme 37: Synthesis of arylated oxidized indole derivative 108 initiated by an EDA complex.
Scheme 38: Synthesis of 4-ketoaldehyde derivative 111 initiated by an EDA complex.
Scheme 39: Mechanism of the synthesis of 4-ketoaldehyde derivative 111.
Scheme 40: Synthesis of perfluoroalkylated olefin 118 initiated by an EDA complex.
Scheme 41: Synthesis of alkylation product 121 initiated by an EDA complex.
Scheme 42: Synthesis of acylation product 123 initiated by an EDA complex.
Scheme 43: Mechanism of the synthesis of acylation product 123.
Scheme 44: Synthesis of trifluoromethylation product 126 initiated by an EDA complex.
Scheme 45: Synthesis of unnatural α-amino acid 129 initiated by an EDA complex.
Scheme 46: Synthesis of thioether derivative 132 initiated by an EDA complex.
Scheme 47: Synthesis of S-aryl dithiocarbamate product 135 initiated by an EDA complex.
Scheme 48: Mechanism of the synthesis of S-aryl dithiocarbamate product 135.
Scheme 49: Synthesis of thioether product 141 initiated by an EDA complex.
Scheme 50: Mechanism of the synthesis of borate product 144.
Scheme 51: Synthesis of boronation product 148 initiated by an EDA complex.
Scheme 52: Synthesis of boration product 151 initiated by an EDA complex.
Scheme 53: Synthesis of boronic acid ester derivative 154 initiated by an EDA complex.
Scheme 54: Synthesis of β-azide product 157 initiated by an EDA complex.
Scheme 55: Decarboxylation reaction initiated by an EDA complex.
Scheme 56: Synthesis of amidated product 162 initiated by an EDA complex.
Scheme 57: Synthesis of diethyl phenylphosphonate 165 initiated by an EDA complex.
Scheme 58: Mechanism of the synthesis of diethyl phenylphosphonate derivative 165.
Scheme 59: Synthesis of (Z)-2-iodovinyl phenyl ether 168 initiated by an EDA complex.
Scheme 60: Mechanism of the synthesis of (Z)-2-iodovinyl phenyl ether derivative 168.
Scheme 61: Dehalogenation reaction initiated by an EDA complex.
Beilstein J. Org. Chem. 2021, 17, 343–378, doi:10.3762/bjoc.17.32
Graphical Abstract
Figure 1: Stabilizing interaction in the CF3CH2+ carbenium ion (top) and structure of the first observable fl...
Scheme 1: Isodesmic equations accounting for the destabilizing effect of the CF3 group. ΔE in kcal⋅mol−1, cal...
Scheme 2: Stabilizing effect of fluorine atoms by resonance electron donation in carbenium ions (δ in ppm).
Scheme 3: Direct in situ NMR observation of α-(trifluoromethyl)carbenium ion or protonated alcohols. Δδ = δ19...
Scheme 4: Reported 13C NMR chemical shifts for the α-(trifluoromethyl)carbenium ion 10c (δ in ppm).
Scheme 5: Direct NMR observation of α-(trifluoromethyl)carbenium ions in situ (δ in ppm).
Scheme 6: Illustration of the ion pair solvolysis mechanism for sulfonate 13f. YOH = solvent.
Figure 2: Solvolysis rate for 13a–i and 17.
Figure 3: Structures of allyl triflates 18 and 19 and allyl brosylate 20. Bs = p-BrC6H4SO2.
Figure 4: Structure of tosylate derivatives 21.
Figure 5: a) Structure of triflate derivatives 22. b) Stereochemistry outcomes of the reaction starting from (...
Scheme 7: Solvolysis reaction of naphthalene and anthracenyl derivatives 26 and 29.
Figure 6: Structure of bisarylated derivatives 34.
Figure 7: Structure of bisarylated derivatives 36.
Scheme 8: Reactivity of 9c in the presence of a Brønsted acid.
Scheme 9: Cationic electrocyclization of 38a–c under strongly acidic conditions.
Scheme 10: Brønsted acid-catalyzed synthesis of indenes 42 and indanes 43.
Scheme 11: Reactivity of sulfurane 44 in triflic acid.
Scheme 12: Solvolysis of triflate 45f in alcoholic solvents.
Scheme 13: Synthesis of labeled 18O-52.
Scheme 14: Reactivity of sulfurane 53 in triflic acid.
Figure 8: Structure of tosylates 56 and 21f.
Scheme 15: Resonance forms in benzylic carbenium ions.
Figure 9: Structure of pyrrole derivatives 58 and 59.
Scheme 16: Resonance structure 60↔60’.
Scheme 17: Ga(OTf)3-catalyzed synthesis of 3,3’- and 3,6’-bis(indolyl)methane from trifluoromethylated 3-indol...
Scheme 18: Proposed reaction mechanism.
Scheme 19: Metal-free 1,2-phosphorylation of 3-indolylmethanols.
Scheme 20: Superacid-mediated arylation of thiophene derivatives.
Scheme 21: In situ mechanistic NMR investigations.
Scheme 22: Proposed mechanisms for the prenyltransferase-catalyzed condensation.
Scheme 23: Influence of a CF3 group on the allylic SN1- and SN2-mechanism-based reactions.
Scheme 24: Influence of the CF3 group on the condensation reaction.
Scheme 25: Solvolysis of 90 in TFE.
Scheme 26: Solvolysis of allyl triflates 94 and 97 and isomerization attempt of 96.
Scheme 27: Proposed mechanism for the formation of 95.
Scheme 28: Formation of α-(trifluoromethyl)allylcarbenium ion 100 in a superacid.
Scheme 29: Lewis acid activation of CF3-substituted allylic alcohols.
Scheme 30: Bimetallic-cluster-stabilized α-(trifluoromethyl)carbenium ions.
Scheme 31: Reactivity of cluster-stabilized α-(trifluoromethyl)carbenium ions.
Scheme 32: α-(Trifluoromethyl)propargylium ion 122↔122’ generated from silyl ether 120 in a superacid.
Scheme 33: Formation of α-(trifluoromethyl)propargylium ions from CF3-substituted propargyl alcohols.
Scheme 34: Direct NMR observation of the protonation of some trifluoromethyl ketones in situ and the correspon...
Scheme 35: Selected resonance forms in protonated fluoroketone derivatives.
Scheme 36: Acid-catalyzed Friedel–Crafts reactions of trifluoromethyl ketones 143a,b and 147a–c.
Scheme 37: Enantioselective hydroarylation of CF3-substituted ketones.
Scheme 38: Acid-catalyzed arylation of ketones 152a–c.
Scheme 39: Reactivity of 156 in a superacid.
Scheme 40: Reactivity of α-CF3-substituted heteroaromatic ketones and alcohols as well as 1,3-diketones.
Scheme 41: Reactivity of 168 with benzene in the presence of a Lewis or Brønsted acid.
Scheme 42: Acid-catalyzed three-component asymmetric reaction.
Scheme 43: Anodic oxidation of amines 178a–c and proposed mechanism.
Scheme 44: Reactivity of 179b in the presence of a strong Lewis acid.
Scheme 45: Trifluoromethylated derivatives as precursors of trifluoromethylated iminium ions.
Scheme 46: Mannich reaction with trifluoromethylated hemiaminal 189.
Scheme 47: Suitable nucleophiles reacting with 192 after Lewis acid activation.
Scheme 48: Strecker reaction involving the trifluoromethylated iminium ion 187.
Scheme 49: Reactivity of 199 toward nucleophiles.
Scheme 50: Reactivity of 204a with benzene in the presence of a Lewis acid.
Scheme 51: Reactivity of α-(trifluoromethyl)-α-chloro sulfides in the presence of strong Lewis acids.
Scheme 52: Anodic oxidation of sulfides 213a–h and Pummerer rearrangement.
Scheme 53: Mechanism for the electrochemical oxidation of the sulfide 213a.
Scheme 54: Reactivity of (trifluoromethyl)diazomethane (217a) in HSO3F.
Figure 10: a) Structure of diazoalkanes 217a–c and b) rate-limiting steps of their decomposition.
Scheme 55: Deamination reaction of racemic 221 and enantioenriched (S)-221.
Scheme 56: Deamination reaction of labeled 221-d2. Elimination products were formed in this reaction, the yiel...
Scheme 57: Deamination reaction of 225-d2. Elimination products were also formed in this reaction in undetermi...
Scheme 58: Formation of 229 from 228 via 1,2-H-shift.
Scheme 59: Deamination reaction of 230. Elimination products were formed in this reaction, the yield of which ...
Scheme 60: Deamination of several diazonium ions. Elimination products were formed in these reactions, the yie...
Scheme 61: Solvolysis reaction mechanism of alkyl tosylates.
Scheme 62: Solvolysis outcome for the tosylates 248 and 249 in HSO3FSbF5.
Figure 11: Solvolysis rate of 248, 249, 252, and 253 in 91% H2SO4.
Scheme 63: Illustration of the reaction pathways. TsCl, pyridine, −5 °C (A); 98% H2SO4, 30 °C (B); 98% H2SO4, ...
Scheme 64: Proposed solvolysis mechanism for the aliphatic tosylate 248.
Scheme 65: Solvolysis of the derivatives 259 and 260.
Scheme 66: Solvolysis of triflate 261. SOH = solvent.
Scheme 67: Intramolecular Friedel–Crafts alkylations upon the solvolysis of triflates 264 and 267.
Scheme 68: α-CF3-enhanced γ-silyl elimination of cyclobutyltosylates 270a,b.
Scheme 69: γ-Silyl elimination in the synthesis of a large variety of CF3-substituted cyclopropanes. Pf = pent...
Scheme 70: Synthetic pathways to 281. aNMR yields.
Scheme 71: The cyclopropyl-substituted homoallylcyclobutylcarbenium ion manifold.
Scheme 72: Reactivity of CF3-substituted cyclopropylcarbinyl derivatives 287a–c. LG = leaving group.
Scheme 73: Reactivity of CF3-substituted cyclopropylcarbinyl derivatives 291a–c.
Scheme 74: Superacid-promoted dimerization or TFP.
Scheme 75: Reactivity of TFP in a superacid.
Scheme 76: gem-Difluorination of α-fluoroalkyl styrenes via the formation of a “hidden” α-RF-substituted carbe...
Scheme 77: Solvolysis of CF3-substituted pentyne 307.
Scheme 78: Photochemical rearrangement of 313.
Figure 12: Structure of 2-norbornylcarbenium ion 318 and argued model for the stabilization of this cation.
Figure 13: Structures and solvolysis rate (TFE, 25 °C) of the sulfonates 319–321. Mos = p-MeOC6H4SO2.
Scheme 79: Mechanism for the solvolysis of 323. SOH = solvent.
Scheme 80: Products formed by the hydrolysis of 328.
Scheme 81: Proposed carbenium ion intermediates in an equilibrium during the solvolysis of tosylates 328, 333,...
Beilstein J. Org. Chem. 2020, 16, 3059–3068, doi:10.3762/bjoc.16.255
Graphical Abstract
Figure 1: Tandem acetate rearrangement/Nazarov cyclization of different substrates.
Figure 2: DFT-computed energy profile of the tandem Au(I)-catalyzed [3,3]-rearrangement/Nazarov reaction of 3...
Figure 3: DFT-computed energy profile of the tandem Au(I)-catalyzed [3,3]-rearrangement/Nazarov reaction of 2...
Figure 4: Computed comparison of the NBO charges of 2- and 3-substituted substrates.
Figure 5: Single-step transformation of IV to IX.
Figure 6: Triflate-promoted hydrogen abstraction and protodeauration with HOTf.
Figure 7: Triflate-mediated abstraction of the hydrogen atom Ha and protodeauration.
Scheme 1: Synthesis of the enynyl acetate starting material 14.
Scheme 2: Synthesis and cyclization of enynyl acetate 20.
Beilstein J. Org. Chem. 2020, 16, 3015–3031, doi:10.3762/bjoc.16.251
Graphical Abstract
Figure 1: Highly-substituted five-membered carbocycle in biologically significant natural products.
Figure 2: Natural product synthesis featuring the all-carbon [3 + 2] cycloaddition. (Quaternary carbon center...
Scheme 1: Representative natural product syntheses that feature the all-carbon [3 + 2] cyclization as the key...
Scheme 2: (A) An intramolecular trimethylenemethane diyl [3 + 2] cycloaddition with allenyl diazo compound 38...
Scheme 3: (A) Palladium-catalyzed intermolecular carboxylative TMM cycloaddition [36]. (B) The proposed mechanism....
Scheme 4: Natural product syntheses that make use of palladium-catalyzed intermolecular [3 + 2] cycloaddition...
Scheme 5: (A) Phosphine-catalyzed [3 + 2] cycloaddition [17]. (B) The proposed mechanism.
Scheme 6: Lu’s [3 + 2] cycloaddition in natural product synthesis. (A) Synthesis of longeracinphyllin A (10) [41]...
Scheme 7: (A) Phosphine-catalyzed [3 + 2] annulation of unsymmetric isoindigo 100 with allene in the preparat...
Scheme 8: (A) Rhodium-catalyzed intracmolecular [3 + 2] cycloaddition [49]. (B) The proposed catalytic cycle of t...
Scheme 9: Total synthesis of natural products reported by Yang and co-workers applying rhodium-catalyzed intr...
Scheme 10: (A) Platinum(II)-catalyzed intermolecular [3 + 2] cycloaddition of propargyl ether 139 and n-butyl ...
Scheme 11: (A) Platinum-catalyzed intramolecular [3 + 2] cycloaddition of propargylic ketal derivative 142 to ...
Scheme 12: (A) Synthesis of phyllocladanol (21) features a Lewis acid-catalyzed formal intramolecular [3 + 2] ...
Scheme 13: The recent advances of [3 + 2] annulation in natural product synthesis. (A) The preparation of melo...
Beilstein J. Org. Chem. 2020, 16, 2888–2902, doi:10.3762/bjoc.16.238
Graphical Abstract
Figure 1: Schematic illustration for the preparation of the catalyst in this work.
Figure 2: FTIR spectra of LS, LS-FAS, and LS-FAS-Cu.
Figure 3: Thermogravimetric weight loss of the obtained materials LS-FAS and LS-FAS-Cu.
Figure 4: FSEM imagine of LS-FAS-Cu in different scale label a) 1 μm, b) 200 nm; FTEM images of LS-FAS-Cu in ...
Figure 5: XPS spectra of LS-FAS-Cu in the regions of C 1s, O 1s, Cu 2p3/2 and Cu LMM (inset).
Scheme 1: Substrate scope of LS-FAS-Cu catalyzed three-component reactions of 4-aminoindoles, alkynes and ald...
Figure 6: Recyclability of LS-FAS-Cu, LS-FM-Cu and Resin-Cu in the reaction between compounds 1a, 2a and 3a.
Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197
Graphical Abstract
Scheme 1: Amine/photoredox-catalysed α-alkylation of aldehydes with alkyl bromides bearing electron-withdrawi...
Scheme 2: Amine/HAT/photoredox-catalysed α-functionalisation of aldehydes using alkenes.
Scheme 3: Amine/cobalt/photoredox-catalysed α-functionalisation of ketones and THIQs.
Scheme 4: Amine/photoredox-catalysed α-functionalisation of aldehydes or ketones with imines. (a) Using keton...
Scheme 5: Bifunctional amine/photoredox-catalysed enantioselective α-functionalisation of aldehydes.
Scheme 6: Bifunctional amine/photoredox-catalysed α-functionalisation of aldehydes using amine catalysts via ...
Scheme 7: Amine/photoredox-catalysed RCA of iminium ion intermediates. (a) Synthesis of quaternary stereocent...
Scheme 8: Bifunctional amine/photoredox-catalysed RCA of enones in a radical chain reaction initiated by an i...
Scheme 9: Bifunctional amine/photoredox-catalysed RCA reactions of iminium ions with different radical precur...
Scheme 10: Bifunctional amine/photoredox-catalysed radical cascade reactions between enones and alkenes with a...
Scheme 11: Amine/photocatalysed photocycloadditions of iminium ion intermediates. (a) External photocatalyst u...
Scheme 12: Amine/photoredox-catalysed addition of acrolein (94) to iminium ions.
Scheme 13: Dual NHC/photoredox-catalysed acylation of THIQs.
Scheme 14: NHC/photocatalysed spirocyclisation via photoisomerisation of an extended Breslow intermediate.
Scheme 15: CPA/photoredox-catalysed aza-pinacol cyclisation.
Scheme 16: CPA/photoredox-catalysed Minisci-type reaction between azaarenes and α-amino radicals.
Scheme 17: CPA/photoredox-catalysed radical additions to azaarenes. (a) α-Amino radical or ketyl radical addit...
Scheme 18: CPA/photoredox-catalysed reduction of azaarene-derived substrates. (a) Reduction of ketones. (b) Ex...
Scheme 19: CPA/photoredox-catalysed radical coupling reactions of α-amino radicals with α-carbonyl radicals. (...
Scheme 20: CPA/photoredox-catalysed Povarov reaction.
Scheme 21: CPA/photoredox-catalysed reactions with imines. (a) Decarboxylative imine generation followed by Po...
Scheme 22: Bifunctional CPA/photocatalysed [2 + 2] photocycloadditions.
Scheme 23: PTC/photocatalysed oxygenation of 1-indanone-derived β-keto esters.
Scheme 24: PTC/photoredox-catalysed perfluoroalkylation of 1-indanone-derived β-keto esters via a radical chai...
Scheme 25: Bifunctional hydrogen bonding/photocatalysed intramolecular [2 + 2] photocycloadditions of quinolon...
Scheme 26: Bifunctional hydrogen bonding/photocatalysed intramolecular RCA cyclisation of a quinolone.
Scheme 27: Bifunctional hydrogen bonding/photocatalysed intramolecular [2 + 2] photocycloadditions of quinolon...
Scheme 28: Bifunctional hydrogen bonding/photocatalysed [2 + 2] photocycloaddition reactions. (a) First use of...
Scheme 29: Bifunctional hydrogen bonding/photocatalysed deracemisation of allenes.
Scheme 30: Bifunctional hydrogen bonding/photocatalysed deracemisation reactions. (a) Deracemisation of sulfox...
Scheme 31: Bifunctional hydrogen bonding/photocatalysed intramolecular [2 + 2] photocycloaddition of coumarins....
Scheme 32: Bifunctional hydrogen bonding/photocatalysed [2 + 2] photocycloadditions of quinolones. (a) Intramo...
Scheme 33: Hydrogen bonding/photocatalysed formal arylation of benzofuranones.
Scheme 34: Hydrogen bonding/photoredox-catalysed dehalogenative protonation of α,α-chlorofluoro ketones.
Scheme 35: Hydrogen bonding/photoredox-catalysed reductions. (a) Reduction of 1,2-diketones. (b) Reduction of ...
Scheme 36: Hydrogen bonding/HAT/photocatalysed deracemisation of cyclic ureas.
Scheme 37: Hydrogen bonding/HAT/photoredox-catalysed synthesis of cyclic sulfonamides.
Scheme 38: Hydrogen bonding/photoredox-catalysed reaction between imines and indoles.
Scheme 39: Chiral cation/photoredox-catalysed radical coupling of two α-amino radicals.
Scheme 40: Chiral phosphate/photoredox-catalysed hydroetherfication of alkenols.
Scheme 41: Chiral phosphate/photoredox-catalysed synthesis of pyrroloindolines.
Scheme 42: Chiral anion/photoredox-catalysed radical cation Diels–Alder reaction.
Scheme 43: Lewis acid/photoredox-catalysed cycloadditions of carbonyls. (a) Formal [2 + 2] cycloaddition of en...
Scheme 44: Lewis acid/photoredox-catalysed RCA reaction using a scandium Lewis acid between α-amino radicals a...
Scheme 45: Lewis acid/photoredox-catalysed RCA reaction using a copper Lewis acid between α-amino radicals and...
Scheme 46: Lewis acid/photoredox-catalysed synthesis of 1,2-amino alcohols from aldehydes and nitrones using a...
Scheme 47: Lewis acid/photocatalysed [2 + 2] photocycloadditions of enones and alkenes.
Scheme 48: Meggers’s chiral-at-metal catalysts.
Scheme 49: Lewis acid/photoredox-catalysed α-functionalisation of ketones with alkyl bromides bearing electron...
Scheme 50: Bifunctional Lewis acid/photoredox-catalysed radical coupling reaction using α-chloroketones and α-...
Scheme 51: Lewis acid/photocatalysed RCA of enones. (a) Using aldehydes as acyl radical precursors. (b) Other ...
Scheme 52: Bifunctional Lewis acid/photocatalysis for a photocycloaddition of enones.
Scheme 53: Lewis acid/photoredox-catalysed RCA reactions of enones using DHPs as radical precursors.
Scheme 54: Lewis acid/photoredox-catalysed functionalisation of β-ketoesters. (a) Hydroxylation reaction catal...
Scheme 55: Bifunctional copper-photocatalysed alkylation of imines.
Scheme 56: Copper/photocatalysed alkylation of imines. (a) Bifunctional copper catalysis using α-silyl amines....
Scheme 57: Bifunctional Lewis acid/photocatalysed intramolecular [2 + 2] photocycloaddition.
Scheme 58: Bifunctional Lewis acid/photocatalysed [2 + 2] photocycloadditions (a) Intramolecular cycloaddition...
Scheme 59: Bifunctional Lewis acid/photocatalysed rearrangement of 2,4-dieneones.
Scheme 60: Lewis acid/photocatalysed [2 + 2] cycloadditions of cinnamate esters and styrenes.
Scheme 61: Nickel/photoredox-catalysed arylation of α-amino acids using aryl bromides.
Scheme 62: Nickel/photoredox catalysis. (a) Desymmetrisation of cyclic meso-anhydrides using benzyl trifluorob...
Scheme 63: Nickel/photoredox catalysis for the acyl-carbamoylation of alkenes with aldehydes using TBADT as a ...
Scheme 64: Bifunctional copper/photoredox-catalysed C–N coupling between α-chloro amides and carbazoles or ind...
Scheme 65: Bifunctional copper/photoredox-catalysed difunctionalisation of alkenes with alkynes and alkyl or a...
Scheme 66: Copper/photoredox-catalysed decarboxylative cyanation of benzyl phthalimide esters.
Scheme 67: Copper/photoredox-catalysed cyanation reactions using TMSCN. (a) Propargylic cyanation (b) Ring ope...
Scheme 68: Palladium/photoredox-catalysed allylic alkylation reactions. (a) Using alkyl DHPs as radical precur...
Scheme 69: Manganese/photoredox-catalysed epoxidation of terminal alkenes.
Scheme 70: Chromium/photoredox-catalysed allylation of aldehydes.
Scheme 71: Enzyme/photoredox-catalysed dehalogenation of halolactones.
Scheme 72: Enzyme/photoredox-catalysed dehalogenative cyclisation.
Scheme 73: Enzyme/photoredox-catalysed reduction of cyclic imines.
Scheme 74: Enzyme/photocatalysed enantioselective reduction of electron-deficient alkenes as mixtures of (E)/(Z...
Scheme 75: Enzyme/photoredox catalysis. (a) Deacetoxylation of cyclic ketones. (b) Reduction of heteroaromatic...
Scheme 76: Enzyme/photoredox-catalysed synthesis of indole-3-ones from 2-arylindoles.
Scheme 77: Enzyme/HAT/photoredox catalysis for the DKR of primary amines.
Scheme 78: Bifunctional enzyme/photoredox-catalysed benzylic C–H hydroxylation of trifluoromethylated arenes.
Beilstein J. Org. Chem. 2020, 16, 2108–2118, doi:10.3762/bjoc.16.178
Graphical Abstract
Figure 1: Examples of biologically active oxazole and aminothiazole scaffolds.
Scheme 1: Strategies for the synthesis of 2,4,5-trisubstituted oxazole from azirine. a) I2, PPh3; b) NaH, 1H-...
Scheme 2: Scope of the α-azidochalcones. The reactions were carried out at reflux temperature, using 1 (1 mmo...
Scheme 3: Large-scale synthesis of 3i.
Figure 2: Large-scale synthesis of 3i. a) At the start of the reaction, b) after the reaction.
Scheme 4: Acetyl derivative of 3d.
Figure 3: ORTEP diagram of compound 5.
Scheme 5: Synthesis of S-methyl/benzylated products 6 and 7.
Scheme 6: Control experiments.
Scheme 7: Plausible mechanism proposed for the formation of 2,4,5-trisubstituted oxazoles 3.
Scheme 8: Reaction of vinyl azide 1 and 3 with ferric nitrate. Reactions were carried out at reflux temperatu...
Figure 4: X-ray crystal structure of 4h.
Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147
Graphical Abstract
Figure 1: Concept of dual synergistic catalysis.
Figure 2: Classification of catalytic systems involving two catalysts.
Figure 3: General mechanism for the dual nickel/photoredox catalytic system.
Figure 4: General mechanisms for C–H activation catalysis involving different reoxidation strategies.
Figure 5: Indole synthesis via dual C–H activation/photoredox catalysis.
Figure 6: Proposed mechanism for the indole synthesis via dual catalysis.
Figure 7: Oxidative Heck reaction on arenes via the dual catalysis.
Figure 8: Proposed mechanism for the Heck reaction on arenes via dual catalysis.
Figure 9: Oxidative Heck reaction on phenols via the dual catalysis.
Figure 10: Proposed mechanism for the Heck reaction on phenols via dual catalysis.
Figure 11: Carbazole synthesis via dual C–H activation/photoredox catalysis.
Figure 12: Proposed mechanism for the carbazole synthesis via dual catalysis.
Figure 13: Carbonylation of enamides via the dual C–H activation/photoredox catalysis.
Figure 14: Proposed mechanism for carbonylation of enamides via dual catalysis.
Figure 15: Annulation of benzamides via the dual C–H activation/photoredox catalysis.
Figure 16: Proposed mechanism for the annulation of benzamides via dual catalysis.
Figure 17: Synthesis of indoles via the dual C–H activation/photoredox catalysis.
Figure 18: Proposed mechanism for the indole synthesis via dual catalysis.
Figure 19: General concept of dual catalysis merging C–H activation and photoredox catalysis.
Figure 20: The first example of dual catalysis merging C–H activation and photoredox catalysis.
Figure 21: Proposed mechanism for the C–H arylation with diazonium salts via dual catalysis.
Figure 22: Dual catalysis merging C–H activation/photoredox using diaryliodonium salts.
Figure 23: Direct arylation via the dual catalytic system reported by Xu.
Figure 24: Direct arylation via dual catalytic system reported by Balaraman.
Figure 25: Direct arylation via dual catalytic system reported by Guo.
Figure 26: C(sp3)–H bond arylation via the dual Pd/photoredox catalytic system.
Figure 27: Acetanilide derivatives acylation via the dual C–H activation/photoredox catalysis.
Figure 28: Proposed mechanism for the C–H acylation with α-ketoacids via dual catalysis.
Figure 29: Acylation of azobenzenes via the dual catalysis C–H activation/photoredox.
Figure 30: C2-acylation of indoles via the dual C–H activation/photoredox catalysis.
Figure 31: Proposed mechanism for the C2-acylation of indoles with aldehydes via dual catalysis.
Figure 32: C2-acylation of indoles via the dual C–H activation/photoredox catalysis.
Figure 33: Perfluoroalkylation of arenes via the dual C–H activation/photoredox catalysis.
Figure 34: Proposed mechanism for perfluoroalkylation of arenes via dual catalysis.
Figure 35: Sulfonylation of 1-naphthylamides via the dual C–H activation/photoredox catalysis.
Figure 36: Proposed mechanism for sulfonylation of 1-naphthylamides via dual catalysis.
Figure 37: meta-C–H Alkylation of arenes via visible-light metallaphotocatalysis.
Figure 38: Alternative procedure for meta-C–H alkylation of arenes via metallaphotocatalysis.
Figure 39: Proposed mechanism for meta-C–H alkylation of arenes via metallaphotocatalysis.
Figure 40: C–H borylation of arenes via visible-light metallaphotocatalysis.
Figure 41: Proposed mechanism for C–H borylation of arenes via visible-light metallaphotocatalysis.
Figure 42: Undirected C–H aryl–aryl cross coupling via dual gold/photoredox catalysis.
Figure 43: Proposed mechanism for the undirected C–H aryl–aryl cross-coupling via dual catalysis.
Figure 44: Undirected C–H arylation of (hetero)arenes via dual manganese/photoredox catalysis.
Figure 45: Proposed mechanism for the undirected arylation of (hetero)arenes via dual catalysis.
Figure 46: Photoinduced C–H arylation of azoles via copper catalysis.
Figure 47: Photo-induced C–H chalcogenation of azoles via copper catalysis.
Figure 48: Decarboxylative C–H adamantylation of azoles via dual cobalt/photoredox catalysis.
Figure 49: Proposed mechanism for the C–H adamantylation of azoles via dual catalysis.
Figure 50: General mechanisms for the “classical” (left) and Cu-free variant (right) Sonogoshira reaction.
Figure 51: First example of a dual palladium/photoredox catalysis for Sonogashira-type couplings.
Figure 52: Arylation of terminal alkynes with diazonium salts via dual gold/photoredox catalysis.
Figure 53: Proposed mechanism for the arylation of terminal alkynes via dual catalysis.
Figure 54: C–H Alkylation of alcohols promoted by H-atom transfer (HAT).
Figure 55: Proposed mechanism for the C–H alkylation of alcohols promoted by HAT.
Figure 56: C(sp3)–H arylation of latent nucleophiles promoted by H-atom transfer.
Figure 57: Proposed mechanism for the C(sp3)–H arylation of latent nucleophiles promoted by HAT.
Figure 58: Direct α-arylation of alcohols promoted by H-atom transfer.
Figure 59: Proposed mechanism for the direct α-arylation of alcohols promoted by HAT.
Figure 60: C–H arylation of amines via dual Ni/photoredox catalysis.
Figure 61: Proposed mechanism for the C–H arylation of amines via dual Ni/photoredox catalysis.
Figure 62: C–H functionalization of nucleophiles via excited ketone/nickel dual catalysis.
Figure 63: Proposed mechanism for the C–H functionalization enabled by excited ketones.
Figure 64: Selective sp3–sp3 cross-coupling promoted by H-atom transfer.
Figure 65: Proposed mechanism for the selective sp3–sp3 cross-coupling promoted by HAT.
Figure 66: Direct C(sp3)–H acylation of amines via dual Ni/photoredox catalysis.
Figure 67: Proposed mechanism for the C–H acylation of amines via dual Ni/photoredox catalysis.
Figure 68: C–H hydroalkylation of internal alkynes via dual Ni/photoredox catalysis.
Figure 69: Proposed mechanism for the C–H hydroalkylation of internal alkynes.
Figure 70: Alternative procedure for the C–H hydroalkylation of ynones, ynoates, and ynamides.
Figure 71: Allylic C(sp3)–H activation via dual Ni/photoredox catalysis.
Figure 72: Proposed mechanism for the allylic C(sp3)–H activation via dual Ni/photoredox catalysis.
Figure 73: Asymmetric allylation of aldehydes via dual Cr/photoredox catalysis.
Figure 74: Proposed mechanism for the asymmetric allylation of aldehydes via dual catalysis.
Figure 75: Aldehyde C–H functionalization promoted by H-atom transfer.
Figure 76: Proposed mechanism for the C–H functionalization of aldehydes promoted by HAT.
Figure 77: Direct C–H arylation of strong aliphatic bonds promoted by HAT.
Figure 78: Proposed mechanism for the C–H arylation of strong aliphatic bonds promoted by HAT.
Figure 79: Direct C–H trifluoromethylation of strong aliphatic bonds promoted by HAT.
Figure 80: Proposed mechanism for the C–H trifluoromethylation of strong aliphatic bonds.
Beilstein J. Org. Chem. 2020, 16, 1722–1731, doi:10.3762/bjoc.16.144
Graphical Abstract
Figure 1: Examples of bioactive nitrogen-containing heterocycles (indole [9], indolone [10], and cinnoline [11] derivati...
Scheme 1: General strategy to access indole, indolone, and cinnoline derivatives from 1,4-diketones.
Scheme 2: Synthesis of the 1,4-diketones 5a–k via the Nef reaction or the Wittig reaction. i) HCHO (aq), DMAP...
Scheme 3: Mechanism of the formation of indole and indolone derivatives.
Scheme 4: Synthesis of the indoles 6a–f and the corresponding side product indolones 7a–f.
Scheme 5: Reaction of 5b with a diamine.
Scheme 6: Synthesis of the indoles 6h–l.
Scheme 7: Synthesis of the indolone derivatives 7b, 7d, and 7g–k.
Scheme 8: Synthesis of the cinnoline derivatives 8a–k.
Scheme 9: Proposed mechanism for the preparation of the compounds 6, 7, and 8.
Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113
Graphical Abstract
Figure 1: Fused aza-hetero polycyclic frames and natural pyrrolizine- and isoindole-containing alkaloids.
Scheme 1: Synthetic approaches for the preparation of pyrrolo-fused aza-hetero polycyclic frames.
Scheme 2: Preparation of 1,2-substituted pyrroles 8a–f and 8i,j.
Scheme 3: Diels–Alder cycloadditions of pyrroles 8a–j and 16a–b with maleimides 7b–c.
Figure 2: Structures of 9m (a) and 10m (b) as determined by single-crystal X-ray diffraction crystallography ...
Scheme 4: Pd(0)-catalyzed intramolecular Heck cross-coupling reaction of 2-vinylpyrroles 8c,d and 8g.
Scheme 5: Synthesis of 2-vinylpyrroles 8k,l and their Pd(0)-catalyzed intramolecular Heck cross-coupling to p...
Scheme 6: Diastereoselective Diels–Alder reaction of pyrrolo[2,1-a]isoindole 18a with 7c.
Scheme 7: Synthetic approach to the fused aza-heterocyclic pentacycle 12.
Figure 3: M06-2X/6-31+G(d,p) Optimized geometry for each of the SCs (a and d), TSs (b and e) and ADs (c and f...
Figure 4: M06-2X/6-31+G(d,p) Optimized geometry for each of the TSs of the Diels–Alder reactions of dienes 8b...
Figure 5: M06-2X/6-31+G(d,p) Optimized geometry of the endo SCs (a) and TSs (b) for the Diels–Alder reaction ...
Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103
Graphical Abstract
Figure 1: Selected examples of organic dyes. Mes-Acr+: 9-mesityl-10-methylacridinium, DCA: 9,10-dicyanoanthra...
Scheme 1: Activation modes in photocatalysis.
Scheme 2: Main strategies for the formation of C(sp3) radicals used in organophotocatalysis.
Scheme 3: Illustrative example for the photocatalytic oxidative generation of radicals from carboxylic acids:...
Scheme 4: Illustrative example for the photocatalytic reductive generation of C(sp3) radicals from redoxactiv...
Figure 2: Common substrates for the photocatalytic oxidative generation of C(sp3) radicals.
Scheme 5: Illustrative example for the photocatalytic oxidative generation of radicals from dihydropyridines ...
Scheme 6: Illustrative example for the photocatalytic oxidative generation of C(sp3) radicals from trifluorob...
Scheme 7: Illustrative example for the photocatalytic reductive generation of C(sp3) radicals from benzylic h...
Scheme 8: Illustrative example for the photocatalytic generation of C(sp3) radicals via direct HAT: the cross...
Scheme 9: Illustrative example for the photocatalytic generation of C(sp3) radicals via indirect HAT: the deu...
Scheme 10: Selected precursors for the generation of aryl radicals using organophotocatalysis.
Scheme 11: Illustrative example for the photocatalytic reductive generation of aryl radicals from aryl diazoni...
Scheme 12: Illustrative examples for the photocatalytic reductive generation of aryl radicals from haloarenes:...
Scheme 13: Illustrative example for the photocatalytic reductive generation of aryl radicals from aryl halides...
Scheme 14: Illustrative example for the photocatalytic reductive generation of aryl radicals from arylsulfonyl...
Scheme 15: Illustrative example for the reductive photocatalytic generation of aryl radicals from triaryl sulf...
Scheme 16: Main strategies towards acyl radicals used in organophotocatalysis.
Scheme 17: Illustrative example for the decarboxylative photocatalytic generation of acyl radicals from α-keto...
Scheme 18: Illustrative example for the oxidative photocatalytic generation of acyl radicals from acyl silanes...
Scheme 19: Illustrative example for the oxidative photocatalytic generation of carbamoyl radicals from 4-carba...
Scheme 20: Illustrative example of the photocatalytic HAT approach for the generation of acyl radicals from al...
Scheme 21: General reactivity of a) radical cations; b) radical anions; c) the main strategies towards aryl an...
Scheme 22: Illustrative example for the oxidative photocatalytic generation of alkene radical cations from alk...
Scheme 23: Illustrative example for the reductive photocatalytic generation of an alkene radical anion from al...
Figure 3: Structure of C–X radical anions and their neutral derivatives.
Scheme 24: Illustrative example for the photocatalytic reduction of imines and the generation of an α-amino C(...
Scheme 25: Illustrative example for the oxidative photocatalytic generation of aryl radical cations from arene...
Scheme 26: NCR classifications and generation.
Scheme 27: Illustrative example for the photocatalytic reductive generation of iminyl radicals from O-aryl oxi...
Scheme 28: Illustrative example for the photocatalytic oxidative generation of iminyl radicals from α-N-oxy ac...
Scheme 29: Illustrative example for the photocatalytic oxidative generation of iminyl radicals via an N–H bond...
Scheme 30: Illustrative example for the photocatalytic oxidative generation of amidyl radicals from Weinreb am...
Scheme 31: Illustrative example for the photocatalytic reductive generation of amidyl radicals from hydroxylam...
Scheme 32: Illustrative example for the photocatalytic reductive generation of amidyl radicals from N-aminopyr...
Scheme 33: Illustrative example for the photocatalytic oxidative generation of amidyl radicals from α-amido-ox...
Scheme 34: Illustrative example for the photocatalytic oxidative generation of aminium radicals: the N-aryltet...
Scheme 35: Illustrative example for the photocatalytic oxidative generation of nitrogen-centered radical catio...
Scheme 36: Illustrative example for the photocatalytic oxidative generation of nitrogen-centered radical catio...
Scheme 37: Illustrative example for the photocatalytic oxidative generation of hydrazonyl radical from hydrazo...
Scheme 38: Generation of O-radicals.
Scheme 39: Illustrative examples for the photocatalytic generation of O-radicals from N-alkoxypyridinium salts...
Scheme 40: Illustrative examples for the photocatalytic generation of O-radicals from alkyl hydroperoxides: th...
Scheme 41: Illustrative example for the oxidative photocatalytic generation of thiyl radicals from thiols: the...
Scheme 42: Main strategies and reagents for the generation of sulfonyl radicals used in organophotocatalysis.
Scheme 43: Illustrative example for the reductive photocatalytic generation of sulfonyl radicals from arylsulf...
Scheme 44: Illustrative example of a Cl atom abstraction strategy for the photocatalytic generation of sulfamo...
Scheme 45: Illustrative example for the oxidative photocatalytic generation of sulfonyl radicals from sulfinic...
Scheme 46: Illustrative example for the photocatalytic generation of electronically excited triplet states: th...
Scheme 47: Illustrative example for the photocatalytic generation of electronically excited triplet states: th...
Beilstein J. Org. Chem. 2020, 16, 1084–1091, doi:10.3762/bjoc.16.95
Graphical Abstract
Scheme 1: Planned approach to tetrasubstituted-4-methylene-3,4-dihydroisoquinolin-1(2H)-ones 4 and 6.
Scheme 2: Preparation of the starting N-propargyl-2-iodobenzamides 2.
Scheme 3: Substrate scope of the reaction of N-propargyl-2-iodobenzamide 2a with arylboronic acids 3b–i.
Scheme 4: Substrate scope of the reaction of N-propargyl-2-iodobenzamides 2c–f with arylboronic acids 3a–c/j.
Scheme 5: Reaction of N-propargyl-2-iodobenzamides 2b,f with the 2-alkynyltrifluoroacetanilides 5a–c.
Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83
Graphical Abstract
Figure 1: Chemical structures of the porphyrinoids and their absorption spectra: in bold are highlighted the ...
Figure 2: Photophysical and photochemical processes (Por = porphyrin). Adapted from [12,18].
Figure 3: Main dual photocatalysts and their oxidative/reductive excited state potentials, including porphyri...
Scheme 1: Photoredox alkylation of aldehydes with diazo acetates using porphyrins and a Ru complex. aUsing a ...
Scheme 2: Proposed mechanism for the alkylation of aldehydes with diazo acetates in the presence of TPP.
Scheme 3: Arylation of heteroarenes with aryldiazonium salts using TPFPP as photocatalyst, and corresponding ...
Scheme 4: A) Scope with different aryldiazonium salts and enol acetates. B) Photocatalytic cycles and compari...
Scheme 5: Photoarylation of isopropenyl acetate A) Comparison between batch and continuous-flow approaches an...
Scheme 6: Dehalogenation induced by red light using thiaporphyrin (STPP).
Scheme 7: Applications of NiTPP as both photoreductant and photooxidant.
Scheme 8: Proposed mechanism for obtaining tetrahydroquinolines by reductive quenching.
Scheme 9: Selenylation and thiolation of anilines.
Scheme 10: NiTPP as photoredox catalyst in oxidative and reductive quenching, in comparison with other photoca...
Scheme 11: C–O bond cleavage of 1-phenylethanol using a cobalt porphyrin (CoTMPP) under visible light.
Scheme 12: Hydration of terminal alkynes by RhIII(TSPP) under visible light irradiation.
Scheme 13: Regioselective photocatalytic hydro-defluorination of perfluoroarenes by RhIII(TSPP).
Scheme 14: Formation of 2-methyl-2,3-dihydrobenzofuran by intramolecular hydro-functionalization of allylpheno...
Scheme 15: Photocatalytic oxidative hydroxylation of arylboronic acids using UNLPF-12 as heterogeneous photoca...
Scheme 16: Photocatalytic oxidative hydroxylation of arylboronic acids using MOF-525 as heterogeneous photocat...
Scheme 17: Preparation of the heterogeneous photocatalyst CNH.
Scheme 18: Photoinduced sulfonation of alkenes with sulfinic acid using CNH as photocatalyst.
Scheme 19: Sulfonic acid scope of the sulfonation reactions.
Scheme 20: Regioselective sulfonation reaction of arimistane.
Scheme 21: Synthesis of quinazolin-4-(3H)-ones.
Scheme 22: Selective photooxidation of aromatic benzyl alcohols to benzaldehydes using Pt/PCN-224(Zn).
Scheme 23: Photooxidation of benzaldehydes to benzoic acids using Pt or Pd porphyrins.
Scheme 24: Photocatalytic reduction of various nitroaromatics using a Ni-MOF.
Scheme 25: Photoinduced cycloadditions of CO2 with epoxides by MOF1.
Figure 4: Electronic configurations of the species of oxygen. Adapted from [66].
Scheme 26: TPP-photocatalyzed generation of 1O2 and its application in organic synthesis. Adapted from [67-69].
Scheme 27: Pericyclic reactions involving singlet oxygen and their mechanisms. Adapted from [67].
Scheme 28: First scaled up ascaridole preparation from α-terpinene.
Scheme 29: Antimalarial drug synthesis using an endoperoxidation approach.
Scheme 30: Photooxygenation of colchicine.
Scheme 31: Synthesis of (−)-pinocarvone from abundant (+)-α-pinene.
Scheme 32: Seeberger’s semi-synthesis of artemisinin.
Scheme 33: Synthesis of artemisinin using TPP and supercritical CO2.
Scheme 34: Synthesis of artemisinin using chlorophyll a.
Scheme 35: Quercitol stereoisomer preparation.
Scheme 36: Photocatalyzed preparation of naphthoquinones.
Scheme 37: Continuous endoperoxidation of conjugated dienes and subsequent rearrangements leading to oxidized ...
Scheme 38: The Opatz group total synthesis of (–)-oxycodone.
Scheme 39: Biomimetic syntheses of rhodonoids A, B, E, and F.
Scheme 40: α-Photooxygenation of chiral aldehydes.
Scheme 41: Asymmetric photooxidation of indanone β-keto esters by singlet oxygen using PTC as a chiral inducer...
Scheme 42: Asymmetric photooxidation of both β-keto esters and β-keto amides by singlet oxygen using PTC-2 as ...
Scheme 43: Bifunctional photo-organocatalyst used for the asymmetric oxidation of β-keto esters and β-keto ami...
Scheme 44: Mechanism of singlet oxygen oxidation of sulfides to sulfoxides.
Scheme 45: Controlled oxidation of sulfides to sulfoxides using protonated porphyrins as photocatalysts. aIsol...
Scheme 46: Photochemical oxidation of sulfides to sulfoxides using PdTPFPP as photocatalyst.
Scheme 47: Controlled oxidation of sulfides to sulfoxides using SnPor@PAF as a photosensitizer.
Scheme 48: Syntheses of 2D-PdPor-COF and 3D-Pd-COF.
Scheme 49: Photocatalytic oxidation of A) thioanisole to methyl phenyl sulfoxide and B) various aryl sulfides,...
Scheme 50: General mechanism for oxidation of amines to imines.
Scheme 51: Oxidation of secondary amines to imines.
Scheme 52: Oxidation of secondary amines using Pd-TPFPP as photocatalyst.
Scheme 53: Oxidative amine coupling using UNLPF-12 as heterogeneous photocatalyst.
Scheme 54: Synthesis of Por-COF-1 and Por-COF-2.
Scheme 55: Photocatalytic oxidation of amines to imines by Por-COF-2.
Scheme 56: Photocyanation of primary amines.
Scheme 57: Synthesis of ᴅ,ʟ-tert-leucine hydrochloride.
Scheme 58: Photocyanation of catharanthine and 16-O-acetylvindoline using TPP.
Scheme 59: Photochemical α-functionalization of N-aryltetrahydroisoquinolines using Pd-TPFPP as photocatalyst.
Scheme 60: Ugi-type reaction with 1,2,3,4-tetrahydroisoquinoline using molecular oxygen and TPP.
Scheme 61: Ugi-type reaction with dibenzylamines using molecular oxygen and TPP.
Scheme 62: Mannich-type reaction of tertiary amines using PdTPFPP as photocatalyst.
Scheme 63: Oxidative Mannich reaction using UNLPF-12 as heterogeneous photocatalyst.
Scheme 64: Transformation of amines to α-cyanoepoxides and the proposed mechanism.
Beilstein J. Org. Chem. 2020, 16, 778–790, doi:10.3762/bjoc.16.71
Graphical Abstract
Figure 1: Structures of trifluoromethylated compounds and their biological activities.
Figure 2: Synthetic approaches toward hydroxyalkylation of indole.
Figure 3: Structures of heterocycles that did not react with ketone 2a.
Scheme 1: Gram-scale synthesis of 2,2,2-trifluoro-1-(1H-indol-3-yl)-1-phenylethan-1-ols (3a and 3p).
Figure 4: Recyclability of the catalytic system n-Bu4PBr/K2CO3 for the preparation of 2,2,2-trifluoro-1-(5-me...
Scheme 2: Synthesis of trifluoromethylated unsymmetrical 3,3'- and 3,6'-DIMs (9–11).
Scheme 3: Proposed mechanism for the preparation of 3a as an example.
Scheme 4: Control experiments.
Beilstein J. Org. Chem. 2020, 16, 691–737, doi:10.3762/bjoc.16.67
Graphical Abstract
Scheme 1: Pharmaceuticals possessing a silicon or boron atom.
Scheme 2: The first Cu-catalyzed C(sp3)–Si bond formation.
Scheme 3: Conversion of benzylic phosphate 6 to the corresponding silane.
Scheme 4: Conversion of alkyl triflates to alkylsilanes.
Scheme 5: Conversion of secondary alkyl triflates to alkylsilanes.
Scheme 6: Conversion of alkyl iodides to alkylsilanes.
Scheme 7: Trapping of intermediate radical through cascade reaction.
Scheme 8: Radical pathway for conversion of alkyl iodides to alkylsilanes.
Scheme 9: Conversion of alkyl ester of N-hydroxyphthalimide to alkylsilanes.
Scheme 10: Conversion of gem-dibromides to bis-silylalkanes.
Scheme 11: Conversion of imines to α-silylated amines (A) and the reaction pathway (B).
Scheme 12: Conversion of N-tosylimines to α-silylated amines.
Scheme 13: Screening of diamine ligands.
Scheme 14: Conversion of N-tert-butylsulfonylimines to α-silylated amines.
Scheme 15: Conversion of aldimines to nonracemic α-silylated amines.
Scheme 16: Conversion of N-tosylimines to α-silylated amines.
Scheme 17: Reaction pathway [A] and conversion of aldehydes to α-silylated alcohols [B].
Scheme 18: Conversion of aldehydes to benzhydryl silyl ethers.
Scheme 19: Conversion of ketones to 1,2-diols (A) and conversion of imines to 1,2-amino alcohols (B).
Scheme 20: Ligand screening (A) and conversion of aldehydes to α-silylated alcohols (B).
Scheme 21: Conversion of aldehydes to α-silylated alcohols.
Scheme 22: 1,4-Additions to α,β-unsaturated ketones.
Scheme 23: 1,4-Additions to unsaturated ketones to give β-silylated derivatives.
Scheme 24: Additions onto α,β-unsaturated lactones to give β-silylated lactones.
Scheme 25: Conversion of α,β-unsaturated to β-silylated lactams.
Scheme 26: Conversion of N-arylacrylamides to silylated oxindoles.
Scheme 27: Conversion of α,β-unsaturated carbonyl compounds to silylated tert-butylperoxides.
Scheme 28: Catalytic cycle for Cu(I) catalyzed α,β-unsaturated compounds.
Scheme 29: Conversion of p-quinone methides to benzylic silanes.
Scheme 30: Conversion of α,β-unsaturated ketimines to regio- and stereocontrolled allylic silanes.
Scheme 31: Conversion of α,β-unsaturated ketimines to enantioenriched allylic silanes.
Scheme 32: Regioselective conversion of dienedioates to allylic silanes.
Scheme 33: Conversion of alkenyl-substituted azaarenes to β-silylated adducts.
Scheme 34: Conversion of conjugated benzoxazoles to enantioenriched β-silylated adducts.
Scheme 35: Conversion of α,β-unsaturated carbonyl indoles to α-silylated N-alkylated indoles.
Scheme 36: Conversion of β-amidoacrylates to α-aminosilanes.
Scheme 37: Conversion of α,β-unsaturated ketones to enantioenriched β-silylated ketones, nitriles, and nitro d...
Scheme 38: Regio-divergent silacarboxylation of allenes.
Scheme 39: Silylation of diazocarbonyl compounds, (A) asymmetric and (B) racemic.
Scheme 40: Enantioselective hydrosilylation of alkenes.
Scheme 41: Conversion of 3-acylindoles to indolino-silanes.
Scheme 42: Proposed mechanism for the silylation of 3-acylindoles.
Scheme 43: Silyation of N-chlorosulfonamides.
Scheme 44: Conversion of acyl silanes to α-silyl alcohols.
Scheme 45: Conversion of N-tosylaziridines to β-silylated N-tosylamines.
Scheme 46: Conversion of N-tosylaziridines to silylated N-tosylamines.
Scheme 47: Conversion of 3,3-disubstituted cyclopropenes to silylated cyclopropanes.
Scheme 48: Conversion of conjugated enynes to 1,3-bis(silyl)propenes.
Scheme 49: Proposed sequence for the Cu-catalyzed borylation of substituted alkenes.
Scheme 50: Cu-catalyzed synthesis of nonracemic allylic boronates.
Scheme 51: Cu–NHC catalyzed synthesis of α-substituted allylboronates.
Scheme 52: Synthesis of α-chiral (γ-alkoxyallyl)boronates.
Scheme 53: Cu-mediated formation of nonracemic cis- or trans- 2-substituted cyclopropylboronates.
Scheme 54: Cu-catalyzed synthesis of γ,γ-gem-difluoroallylboronates.
Scheme 55: Cu-catalyzed hydrofunctionalization of internal alkenes and vinylarenes.
Scheme 56: Cu-catalyzed Markovnikov and anti-Markovnikov borylation of alkenes.
Scheme 57: Cu-catalyzed borylation/ortho-cyanation/Cope rearrangement.
Scheme 58: Borylfluoromethylation of alkenes.
Scheme 59: Cu-catalyzed synthesis of tertiary nonracemic alcohols.
Scheme 60: Synthesis of densely functionalized and synthetically versatile 1,2- or 4,3-borocyanated 1,3-butadi...
Scheme 61: Cu-catalyzed trifunctionalization of allenes.
Scheme 62: Cu-catalyzed selective arylborylation of arenes.
Scheme 63: Asymmetric borylative coupling between styrenes and imines.
Scheme 64: Regio-divergent aminoboration of unactivated terminal alkenes.
Scheme 65: Cu-catalyzed 1,4-borylation of α,β-unsaturated ketones.
Scheme 66: Cu-catalyzed protodeboronation of α,β-unsaturated ketones.
Scheme 67: Cu-catalyzed β-borylation of α,β-unsaturated imines.
Scheme 68: Cu-catalyzed synthesis of β-trifluoroborato carbonyl compounds.
Scheme 69: Asymmetric 1,4-borylation of α,β-unsaturated carbonyl compounds.
Scheme 70: Cu-catalyzed ACB and ACA reactions of α,β-unsaturated 2-acyl-N-methylimidazoles.
Scheme 71: Cu-catalyzed diborylation of aldehydes.
Scheme 72: Umpolung pathway for chiral, nonracemic tertiary alcohol synthesis (top) and proposed mechanism for...
Scheme 73: Cu-catalyzed synthesis of α-hydroxyboronates.
Scheme 74: Cu-catalyzed borylation of ketones.
Scheme 75: Cu-catalyzed borylation of unactivated alkyl halides.
Scheme 76: Cu-catalyzed borylation of allylic difluorides.
Scheme 77: Cu-catalyzed borylation of cyclic and acyclic alkyl halides.
Scheme 78: Cu-catalyzed borylation of unactivated alkyl chlorides and bromides.
Scheme 79: Cu-catalyzed decarboxylative borylation of carboxylic acids.
Scheme 80: Cu-catalyzed borylation of benzylic, allylic, and propargylic alcohols.
Beilstein J. Org. Chem. 2020, 16, 657–662, doi:10.3762/bjoc.16.62
Graphical Abstract
Figure 1: Representative examples of biologically active pyrrolo[1,2-a]indol-3-one derivatives.
Scheme 1: Radical cascade trifluoromethylthiolation and cyclization reactions.
Scheme 2: Cascade bis(trifluoromethylthiolation) and cyclization of N-[(3-aryl)propioloyl]indoles 1. Reaction...
Scheme 3: Cascade trifluoromethylthiolation and cyclization of N-[(3-aryl)propioloyl]indoles 3. Reaction cond...
Scheme 4: Proposed reaction mechanism.
Beilstein J. Org. Chem. 2020, 16, 587–595, doi:10.3762/bjoc.16.53
Graphical Abstract
Figure 1: (a) Chemical structures of BODIPY (1) and dipyrromethane (2). (b) C–C bond forming alkynylations of...
Scheme 1: Synthesis of α-ethynyl-substituted BODIPY derivatives 3a and 4a.
Scheme 2: Synthesis of β-ethynyl-substituted BODIPY derivatives 5a and 5b and β,β'-diethynyl-substituted comp...
Figure 2: Top and front views of the crystal structures of (a) 4a and (b) 6b with 50% thermal ellipsoid proba...
Figure 3: Partial 1H NMR spectra of (a) 1a, (b) 3a, (c) 4a, (d) 5a, and (e) 6a recorded in CDCl3 at 298 K. As...
Figure 4: UV–vis absorption spectra of the BODIPY derivatives, (a) 1a (green), 3a (blue), 4a (red), and (b) 1a...
Figure 5: Fluorescence spectra of BODIPY derivatives. (a) 1a (green), 3a (blue), 4a (red) and (b) 1a (green), ...
Beilstein J. Org. Chem. 2020, 16, 451–481, doi:10.3762/bjoc.16.42
Graphical Abstract
Scheme 1: [Cu(I)(dap)2]Cl-catalyzed ATRA reaction under green light irradiation.
Scheme 2: Photocatalytic allylation of α-haloketones.
Scheme 3: [Cu(I)(dap)2]Cl-photocatalyzed chlorosulfonylation and chlorotrifluoromethylation of alkenes.
Scheme 4: Photocatalytic perfluoroalkylchlorination of electron-deficient alkenes using the Sauvage catalyst.
Scheme 5: Photocatalytic synthesis of fluorinated sultones.
Scheme 6: Photocatalyzed haloperfluoroalkylation of alkenes and alkynes.
Scheme 7: Chlorosulfonylation of alkenes catalyzed by [Cu(I)(dap)2]Cl. aNo Na2CO3 was added. b1 equiv of Na2CO...
Scheme 8: Copper-photocatalyzed reductive allylation of diaryliodonium salts.
Scheme 9: Copper-photocatalyzed azidomethoxylation of olefins.
Scheme 10: Benzylic azidation initiated by [Cu(I)(dap)2]Cl.
Scheme 11: Trifluoromethyl methoxylation of styryl derivatives using [Cu(I)(dap)2]PF6. All redox potentials ar...
Scheme 12: Trifluoromethylation of silyl enol ethers.
Scheme 13: Synthesis of annulated heterocycles upon oxidation with the Sauvage catalyst.
Scheme 14: Oxoazidation of styrene derivatives using [Cu(dap)2]Cl as a precatalyst.
Scheme 15: [Cu(I)(dpp)(binc)]PF6-catalyzed ATRA reaction.
Scheme 16: Allylation reaction of α-bromomalonate catalyzed by [Cu(I)(dpp)(binc)]PF6 following an ATRA mechani...
Scheme 17: Bromo/tribromomethylation reaction using [Cu(I)(dmp)(BINAP)]PF6.
Scheme 18: Chlorotrifluoromethylation of alkenes catalyzed by [Cu(I)(N^N)(xantphos)]PF6.
Scheme 19: Chlorosulfonylation of styrene and alkyne derivatives by ATRA reactions.
Scheme 20: Reduction of aryl and alkyl halides with the complex [Cu(I)(bcp)(DPEPhos)]PF6. aIrradiation was car...
Scheme 21: Meerwein arylation of electron-rich aromatic derivatives and 5-exo-trig cyclization catalyzed by th...
Scheme 22: [Cu(I)(bcp)(DPEPhos)]PF6-photocatalyzed synthesis of alkaloids. aYield over two steps (cyclization ...
Scheme 23: Copper-photocatalyzed decarboxylative amination of NHP esters.
Scheme 24: Photocatalytic decarboxylative alkynylation using [Cu(I)(dq)(binap)]BF4.
Scheme 25: Copper-photocatalyzed alkylation of glycine esters.
Scheme 26: Copper-photocatalyzed borylation of organic halides. aUnder continuous flow conditions.
Scheme 27: Copper-photocatalyzed α-functionalization of alcohols with glycine ester derivatives.
Scheme 28: δ-Functionalization of alcohols using [Cu(I)(dmp)(xantphos)]BF4.
Scheme 29: Photocatalytic synthesis of [5]helicene and phenanthrene.
Scheme 30: Oxidative carbazole synthesis using in situ-formed [Cu(I)(dmp)(xantphos)]BF4.
Scheme 31: Copper-photocatalyzed functionalization of N-aryl tetrahydroisoquinolines.
Scheme 32: Bicyclic lactone synthesis using a copper-photocatalyzed PCET reaction.
Scheme 33: Photocatalytic Pinacol coupling reaction catalyzed by [Cu(I)(pypzs)(BINAP)]BF4. The ligands of the ...
Scheme 34: Azide photosensitization using a Cu-based photocatalyst.
Beilstein J. Org. Chem. 2020, 16, 248–280, doi:10.3762/bjoc.16.26
Graphical Abstract
Figure 1: List of photoredox catalysts used for C–H bond functionalizations.
Figure 2: List of metal-based photoredox catalysts used in this review article.
Figure 3: Jablonski diagram.
Figure 4: Photoredox catalysis via reductive or oxidative pathways. D = donor, A = acceptor, S = substrate, P...
Figure 5: Schematic representation of the combination of photoredox catalysis and transition metal catalysis.
Scheme 1: Weinreb amide C–H olefination.
Figure 6: Mechanism for the formation of 21 from 19 using photoredox catalyst 11.
Scheme 2: C–H olefination of phenolic ethers.
Scheme 3: Decarboxylative acylation of acetanilides.
Figure 7: Mechanism for the formation of 30 from acetanilide derivatives.
Scheme 4: Synthesis of fluorenone derivatives by intramolecular deoxygenative acylation of biaryl carboxylic ...
Figure 8: Mechanism for the photoredox-catalyzed synthesis of fluorenone derivatives.
Scheme 5: Synthesis of benzothiazoles via aerobic C–H thiolation.
Figure 9: Plausible mechanism for the construction of benzothiazoles from benzothioamides.
Scheme 6: Synthesis of benzothiazoles via oxidant-free C–H thiolation.
Figure 10: Mechanism involved in the synthesis of benzothiazoles via oxidant-free C–H thiolation.
Scheme 7: Synthesis of indoles via C–H cyclization of anilides with alkynes.
Scheme 8: Preparation of 3-trifluoromethylcoumarins via C–H cyclization of arylpropiolate esters.
Figure 11: Mechanistic pathway for the synthesis of coumarin derivatives via C–H cyclization.
Scheme 9: Monobenzoyloxylation without chelation assistance.
Figure 12: Plausible mechanism for the formation of 71 from 70.
Scheme 10: Aryl-substituted arenes prepared by inorganic photoredox catalysis using 12a.
Figure 13: Proposed mechanism for C–H arylations in the presence of 12a and a Pd catalyst.
Scheme 11: Arylation of purines via dual photoredox catalysis.
Scheme 12: Arylation of substituted arenes with an organic photoredox catalyst.
Scheme 13: C–H trifluoromethylation.
Figure 14: Proposed mechanism for the trifluoromethylation of 88.
Scheme 14: Synthesis of benzo-3,4-coumarin derivatives.
Figure 15: Plausible mechanism for the synthesis of substituted coumarins.
Scheme 15: Oxidant-free oxidative phosphonylation.
Figure 16: Mechanism proposed for the phosphonylation reaction of 100.
Scheme 16: Nitration of anilines.
Figure 17: Plausible mechanism for the nitration of aniline derivatives via photoredox catalysis.
Scheme 17: Synthesis of carbazoles via intramolecular amination.
Figure 18: Proposed mechanism for the formation of carbazoles from biaryl derivatives.
Scheme 18: Synthesis of substituted phenols using QuCN.
Figure 19: Mechanism for the synthesis of phenol derivatives with photoredox catalyst 8.
Scheme 19: Synthesis of substituted phenols with DDQ (5).
Figure 20: Possible mechanism for the generation of phenols with the aid of photoredox catalyst 5.
Scheme 20: Aerobic bromination of arenes using an acridinium-based photocatalyst.
Scheme 21: Aerobic bromination of arenes with anthraquinone.
Figure 21: Proposed mechanism for the synthesis of monobrominated compounds.
Scheme 22: Chlorination of benzene derivatives with Mes-Acr-MeClO4 (2).
Figure 22: Mechanism for the synthesis of 131 from 132.
Scheme 23: Chlorination of arenes with 4CzIPN (5a).
Figure 23: Plausible mechanism for the oxidative photocatalytic monochlorination using 5a.
Scheme 24: Monofluorination using QuCN-ClO4 (8).
Scheme 25: Fluorination with fluorine-18.
Scheme 26: Aerobic amination with acridinium catalyst 3a.
Figure 24: Plausible mechanism for the aerobic amination using acridinium catalyst 3a.
Scheme 27: Aerobic aminations with semiconductor photoredox catalyst 18.
Scheme 28: Perfluoroalkylation of arenes.
Scheme 29: Synthesis of benzonitriles in the presence of 3a.
Figure 25: Plausible mechanism for the synthesis of substituted benzonitrile derivatives in the presence of 3a....
Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16
Graphical Abstract
Figure 1: Biologically and medicinally important 3-alkenylindoles.
Scheme 1: a) Previous and b) present work related to the synthesis of 3-alkenylindoles.
Scheme 2: Substrate scope for the C–H alkenylation of the indoles 1. Reaction conditions: 1 (1 mmol), 2 (2 mm...
Scheme 3: a) Three-phase test to determine a homogeneous or heterogeneous catalytic mechanism of action for t...
Scheme 4: Probable catalytic mechanism for the transformation of 1a by the RuNC.
Beilstein J. Org. Chem. 2019, 15, 2830–2839, doi:10.3762/bjoc.15.276
Graphical Abstract
Figure 1: Pharmacologically relevant furoindoles.
Scheme 1: Synthesis of benzo[4,5]furo[3,2-b]indoles 5a–j. Conditions: (i) 1.2 equiv 2-bromophenylboronic acid...
Figure 2: Ortep of 5c (propability of ellipsoids: 45%).
Figure 3: Diindolofurans 6a–e.
Figure 4: Illustration of binding poses of selected inhibitors for the ENPP1 homology model: (a): suramin, (b...
Figure 5: 3D poses of docked selected inhibitors inside homology model of ENPP3. (a): suramin, (b): 5e, (c): ...