Search for "ligand" in Full Text gives 993 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182
Graphical Abstract
Figure 1: Representative modified 1,3-oxathiolane nucleoside analogues.
Figure 2: Mechanism of antiviral action of 1,3-oxathiolane nucleosides, 3TC (1) and FTC (2), as chain termina...
Figure 3: Synthetic strategies for the construction of the 1,3-oxathiolane sugar ring.
Scheme 1: Synthesis of 4 from benzoyloxyacetaldehyde (3a) and 2-mercapto-substituted dimethyl acetal 3na.
Scheme 2: Synthesis of 8 from protected glycolic aldehyde 3b and 2-mercaptoacetic acid (3o).
Scheme 3: Synthesis of 20 from ᴅ-mannose (3c).
Scheme 4: Synthesis of 20 from 1,6-thioanhydro-ᴅ-galactose (3d).
Scheme 5: Synthesis of 8 from 2-(tert-butyldiphenylsilyloxy)methyl-5-oxo-1,2-oxathiolane (3m).
Scheme 6: Synthesis of 20a from ʟ-gulose derivative 3f.
Scheme 7: Synthesis of 31 from (+)-thiolactic acid 3p and 2-benzoyloxyacetaldehyde (3a).
Scheme 8: Synthesis of 35a from 1,4-dithiane-2,5-diol (3q) and glyoxylic acid (3g) hydrate.
Scheme 9: Synthetic routes toward 41 through Pummerer reaction from methyl 2-mercaptoacetate (3j) and bromoac...
Scheme 10: Strategy for the synthesis of 2,5-substituted 1,3-oxathiolane 41a using 4-nitrobenzyl glyoxylate an...
Scheme 11: Synthesis of 44 by a resolution method using Mucor miehei lipase.
Scheme 12: Synthesis of 45 from benzoyloxyacetaldehyde (3a) and 2-mercaptoacetaldehyde bis(2-methoxyethyl) ace...
Scheme 13: Synthesis of 46 from 2-mercaptoacetaldehyde bis(2-methoxyethyl) acetal (3nc) and diethyl 3-phosphon...
Scheme 14: Synthesis of 48 from 1,3-dihydroxyacetone dimer 3l.
Scheme 15: Approach toward 52 from protected alkene 3rb and lactic acid derivative 51 developed by Snead et al....
Scheme 16: Recent approach toward 56a developed by Kashinath et al.
Scheme 17: Synthesis of 56a from ʟ-menthyl glyoxylate (3h) hydrate by DKR.
Scheme 18: Possible mechanism with catalytic TEA for rapid interconversion of isomers.
Scheme 19: Synthesis of 35a by a classical resolution method through norephedrine salt 58 formation.
Scheme 20: Synthesis of 63 via [1,2]-Brook rearrangement from silyl glyoxylate 61 and thiol 3nb.
Scheme 21: Combined use of STS and CAL-B as catalysts to synthesize an enantiopure oxathiolane precursor 65.
Scheme 22: Synthesis of 1 and 1a from glycolaldehyde dimer 64 and 1,4-dithiane-2,5-diol (3q) using STS and CAL...
Scheme 23: Synthesis of 68 by using Klebsiella oxytoca.
Scheme 24: Synthesis of 71 and 72 using Trichosporon taibachii lipase and kinetic resolution.
Scheme 25: Synthesis of 1,3-oxathiolan-5-ones 77 and 78 via dynamic covalent kinetic resolution.
Figure 4: Pathway for glycosidic bond formation.
Scheme 26: First synthesis of (±)-BCH-189 (1c) by Belleau et al.
Scheme 27: Enantioselective synthesis of 3TC (1).
Scheme 28: Synthesis of cis-diastereomer 3TC (1) from oxathiolane propionate 44.
Scheme 29: Synthesis of (±)-BCH-189 (1c) via SnCl4-mediated N-glycosylation of 8.
Scheme 30: Synthesis of (+)-BCH-189 (1a) via TMSOTf-mediated N-glycosylation of 20.
Scheme 31: Synthesis of 3TC (1) from oxathiolane precursor 20a.
Scheme 32: Synthesis of 83 via N-glycosylation of 20 with pyrimidine bases.
Scheme 33: Synthesis of 85 via N-glycosylation of 20 with purine bases.
Scheme 34: Synthesis of 86 and 87 via N-glycosylation using TMSOTf and pyrimidines.
Scheme 35: Synthesis of 90 and 91 via N-glycosylation using TMSOTf and purines.
Scheme 36: Synthesis of 3TC (1) via TMSI-mediated N-glycosylation.
Scheme 37: Stereoselective N-glycosylation for the synthesis of 1 by anchimeric assistance of a chiral auxilia...
Scheme 38: Whitehead and co-workers’ approach for the synthesis of 1 via direct N-glycosylation without an act...
Scheme 39: ZrCl4-mediated stereoselective N-glycosylation.
Scheme 40: Plausible reaction mechanism for stereoselective N-glycosylation using ZrCl4.
Scheme 41: Synthesis of enantiomerically pure oxathiolane nucleosides 1 and 2.
Scheme 42: Synthesis of tetrazole analogues of 1,3-oxathiolane nucleosides 97.
Scheme 43: Synthetic approach toward 99 from 1,3-oxathiolane 45 by Camplo et al.
Scheme 44: Synthesis of 100 from oxathiolane phosphonate analogue 46.
Scheme 45: Synthetic approach toward 102 and the corresponding cyclic thianucleoside monophosphate 102a by Cha...
Scheme 46: Synthesis of emtricitabine (2) from 1,4-dithiane-2,5-diol (3q) and glyoxylic acid (3g).
Scheme 47: Synthesis of 1 and 2, respectively, from 56a–d using iodine-mediated N-glycosylation.
Scheme 48: Plausible mechanism for silane- and I2-mediated N-glycosylation.
Scheme 49: Pyridinium triflate-mediated N-glycosylation of 35a.
Scheme 50: Possible pathway for stereoselective N-glycosylation via in situ chelation with a metal ligand.
Scheme 51: Synthesis of novel 1,3-oxathiolane nucleoside 108 from oxathiolane precursor 8 and 3-benzyloxy-2-me...
Scheme 52: Synthesis of 110 using T-705 as a nucleobase and 1,3-oxathiolane derivative 8 via N-glycosylation.
Scheme 53: Synthesis of 1 using an asymmetric leaving group and N-glycosylation with bromine and mesitylene.
Scheme 54: Cytidine deaminase for enzymatic separation of 1c.
Scheme 55: Enzymatic resolution of the monophosphate derivative 116 for the synthesis of (−)-BCH-189 (1) and (...
Scheme 56: Enantioselective resolution by PLE-mediated hydrolysis to obtain FTC (2).
Scheme 57: (+)-Menthyl chloroformate as a resolving agent to separate a racemic mixture 120.
Scheme 58: Separation of racemic mixture 1c by cocrystal 123 formation with (S)-(−)-BINOL.
Beilstein J. Org. Chem. 2021, 17, 2657–2662, doi:10.3762/bjoc.17.179
Graphical Abstract
Scheme 1: A: Synthesis of (Z)-β-enamido triflates and subsequent stereoselective cross-coupling reactions. B:...
Scheme 2: Substrate scope of the Suzuki coupling leading to enamides 2 and 3. aRatio determined by 19F NMR; b...
Scheme 3: Proposed mechanisms for the formed Suzuki coupling retention products 2 and inversion products 3.
Beilstein J. Org. Chem. 2021, 17, 2650–2656, doi:10.3762/bjoc.17.178
Graphical Abstract
Scheme 1: C(sp3)–H alkynylation of tetrahydroisoquinolines. L* = chiral ligand. TEMPO = 2,2,6,6-tetramethylpi...
Scheme 2: Substrate scope. Reaction conditions: Pt anode, Pt cathode, interelectrode distance 0.25 mm, 1 (0.0...
Scheme 3: Reaction scale-up.
Scheme 4: Proposed mechanism.
Beilstein J. Org. Chem. 2021, 17, 2570–2584, doi:10.3762/bjoc.17.172
Graphical Abstract
Figure 1: Generalized α-ketol or α-iminol rearrangement.
Figure 2: Nickel(II)-catalyzed enantioselective rearrangement of ketol 3 to form the ring-expanded and chiral...
Figure 3: Enantioselective ring expansion of β-hydroxy-α-dicarbonyl 6 catalyzed by a chiral copper-bisoxazoli...
Figure 4: Enantioselective rearrangement of ketols 9 and 12 and hydroxyaldimine 14 catalyzed by Al(III) or Sc...
Figure 5: Asymmetric rearrangement of α,α-dialkyl-α-siloxyaldehydes 16 to α-siloxyketones 17 catalyzed by chi...
Figure 6: BF3-promoted diastereospecific rearrangement of α-ketol 21 to difluoroalkoxyborane 22.
Figure 7: In the presence of a gold catalyst and water in 1,4-dioxane, 1-alkynylbutanol derivatives undergo t...
Figure 8: The diastereospecific α-ketol rearrangement of 32 to 33, part of the total synthesis of periconiano...
Figure 9: Two α-ketol rearrangements, one catalyzed by silica gel on 38 and the other by NaOMe on both 38 and ...
Figure 10: α-Ketol rearrangement of triumphalone (41) to isotriumphalone (42) via ring contraction.
Figure 11: Tandem reaction of strophasterol A synthetic intermediate 43 to 44 through a vinylogous α-ketol rea...
Figure 12: Tandem reaction consisting of a Diels–Alder cycloaddition followed by an α-ketol rearrangement, par...
Figure 13: Single-pot reaction consisting of Claisen and α-ketol rearrangements, part of the total synthesis o...
Figure 14: Enzyme-catalyzed α-ketol rearrangements. a) Ketol-acid reductoisomerase (KAR) catalyzes the rearran...
Figure 15: The conversion of asperfloroid (73) to asperflotone (72), featuring the ring-expanding α-ketol rear...
Figure 16: Hypothetical interconversion of natural products prekinamycin (76) and isoprekinamycin (77) and che...
Figure 17: Proposed biosynthetic pathway converting acylphloroglucinol (87) to isolated elodeoidins A–H 92–96....
Figure 18: α-Iminol rearrangements catalyzed by VANOL Zr (99). The rearrangement can be conducted with preform...
Figure 19: α-Iminol rearrangements catalyzed by silica gel and montmorillonite K 10. a) For 102a (102 with R =...
Figure 20: Synthesis of tryptamines 110 via a ring-contracting α‑iminol rearrangement. A mechanism for the fin...
Figure 21: Tandem synthesis of functionalized α-amino cyclopentanones 119 from heteroarenes 115 and cyclobutan...
Figure 22: Four eburnane-type alkaloid natural products 122–125 were synthesized from common intermediate 127,...
Beilstein J. Org. Chem. 2021, 17, 2520–2542, doi:10.3762/bjoc.17.169
Graphical Abstract
Scheme 1: Photoredox catalysis mechanism of [Ru(bpy)3]2+.
Scheme 2: Photoredox catalysis mechanism of CuI.
Scheme 3: Ligands and CuI complexes.
Scheme 4: Mechanism of CuI-based photocatalysis.
Scheme 5: Mechanisms of CuI–substrate complexes.
Scheme 6: Mechanism of CuII-base photocatalysis.
Scheme 7: Olefinic C–H functionalization and allylic alkylation.
Scheme 8: Cross-coupling of unactivated alkenes and CF3SO2Cl.
Scheme 9: Chlorosulfonylation/cyanofluoroalkylation of alkenes.
Scheme 10: Hydroamination of alkenes.
Scheme 11: Cross-coupling reaction of alkenes, alkyl halides with nucleophiles.
Scheme 12: Cross-coupling of alkenes with oxime esters.
Scheme 13: Oxo-azidation of vinyl arenes.
Scheme 14: Azidation/difunctionalization of vinyl arenes.
Scheme 15: Photoinitiated copper-catalyzed Sonogashira reaction.
Scheme 16: Alkyne functionalization reactions.
Scheme 17: Alkynylation of dihydroquinoxalin-2-ones with terminal alkynes.
Scheme 18: Decarboxylative alkynylation of redox-active esters.
Scheme 19: Aerobic oxidative C(sp)–S coupling reaction.
Scheme 20: Copper-catalyzed alkylation of carbazoles with alkyl halides.
Scheme 21: C–N coupling of organic halides with amides and aliphatic amines.
Scheme 22: Copper-catalyzed C–X (N, S, O) bond formation reactions.
Scheme 23: Arylation of C(sp2)–H bonds of azoles.
Scheme 24: C–C cross-coupling of aryl halides and heteroarenes.
Scheme 25: Benzylic or α-amino C–H functionalization.
Scheme 26: α-Amino C–H functionalization of aromatic amines.
Scheme 27: C–H functionalization of aromatic amines.
Scheme 28: α-Amino-C–H and alkyl C–H functionalization reactions.
Scheme 29: Other copper-photocatalyzed reactions.
Scheme 30: Cross-coupling of oxime esters with phenols or amines.
Scheme 31: Alkylation of heteroarene N-oxides.
Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166
Graphical Abstract
Scheme 1: Schematic representation of the polymer synthesis of P1 and P2.
Figure 1: DSC-analysis of the polymers P1 and P2 (second heating and cooling cycle; 20 K/min for heating and ...
Figure 2: DMTA analysis of P1 and P2 showing the transition at around 130 °C due to the reversible π–π intera...
Figure 3: Frequency sweeps of polymers P1 (left) and P2 (right).
Figure 4: Temperature dependent IR spectra of P1 drop casted on KBr in the C=C (1570–1605 cm−1) and C=O stret...
Figure 5: Schematic representation of the first healing of P1 at 150 °C.
Beilstein J. Org. Chem. 2021, 17, 2488–2495, doi:10.3762/bjoc.17.165
Graphical Abstract
Scheme 1: 3d-Transition-metal-catalyzed C–H functionalization to access functionalized ferrocenes.
Scheme 2: Scope of ferrocenes with morpholine.
Scheme 3: Scope of various amines with 1a.
Scheme 4: Synthetic applications.
Scheme 5: Mechanistic experiments.
Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164
Graphical Abstract
Figure 1: Structures of azide and alkyne functional molecules and polymers used in the photoinduced CuAAC rea...
Figure 2: UV–vis spectra of CuICl, CuIICl2 and BPNs.
Figure 3: a) 1H NMR spectra of the model reaction between benzyl azide (Az-1) and phenylacetylene (Alk-3) bef...
Scheme 1: Proposed mechanism for photoinduced CuAAC reaction using exfoliated BPNs.
Figure 4: a) 1H NMR spectrum of chain end modified PCL-Anth; b) UV–vis spectra of (azidomethyl)anthracene (bl...
Scheme 2: Synthesis of PS-b-PCL block copolymer via exfoliated BPNs-mediated photoinduced CuAAC reaction.
Figure 5: a) GPC traces of PS-Az, PCL-Alk and block copolymer (Ps-b-PCL) b) 1H NMR spectrum of the block copo...
Scheme 3: Preparation of the cross-linked polymer by CuAAC reaction using multifunctional monomers, Az-3 and ...
Figure 6: a) DSC thermogram of photoinduced synthesis of nanocomposite networks (heating rate: 10 °C/min). b)...
Figure 7: (a, b) TEM images of cross-linked polymer at two different magnifications, c) HAADF-STEM image and ...
Beilstein J. Org. Chem. 2021, 17, 2462–2476, doi:10.3762/bjoc.17.163
Graphical Abstract
Scheme 1: Ag/I2-mediated electrophilic annulation of 2-en-4-ynyl azides 1.
Scheme 2: The proposed mechanism of Ag-catalyzed aza-annulation.
Scheme 3: The proposed mechanism of I2-mediated aza-annulation.
Scheme 4: Copper-catalyzed amination of (E)-2-en-4-ynyl azides 1.
Scheme 5: The proposed mechanism of copper-catalyzed amination.
Scheme 6: The derivatization of sulfonated aminonicotinates.
Scheme 7: Copper-catalyzed chalcogenoamination of (E)-2-en-4-ynyl azides 1.
Scheme 8: The possible mechanism of chalcogenoamination.
Scheme 9: The derivatization of 5‑selenyl- and 5-sulfenyl-substituted nicotinates.
Scheme 10: The tandem reaction of nitriles, Reformatsky reagents, and 1,3-enynes.
Scheme 11: Nickel-catalyzed [4 + 2]-cycloaddition of 3-azetidinones with 1,3-enynes.
Scheme 12: Electrophilic iodocyclization of 2-nitro-1,3-enynes to pyrroles.
Scheme 13: Electrophilic halogenation of 2-trifluoromethyl-1,3-enynes to pyrroles.
Scheme 14: Copper-catalyzed cascade cyclization of 2-nitro-1,3-enynes with amines.
Scheme 15: Tandem cyclization of 2-nitro-1,3-enynes, Togni reagent II, and amines.
Scheme 16: Tandem cyclization of 2-nitro-1,3-enynes, TMSN3, and amines.
Scheme 17: Cascade cyclization of 6-hydroxyhex-2-en-4-ynals to pyrroles.
Scheme 18: Au/Ag-catalyzed oxidative aza-annulation of 1,3-enynyl azides.
Scheme 19: The plausible mechanism of Au/Ag-catalyzed oxidative aza-annulation.
Scheme 20: Synthesis of 2-tetrazolyl-substituted 3-acylpyrroles from enynals.
Scheme 21: CuH-catalyzed coupling reaction of 1,3-enynes and nitriles to pyrroles.
Scheme 22: The mechanism of CuH-catalyzed coupling of 1,3-enynes and nitriles to pyrroles.
Beilstein J. Org. Chem. 2021, 17, 2399–2416, doi:10.3762/bjoc.17.157
Graphical Abstract
Figure 1: Structures of brevipolides A–O (1 – 15).
Scheme 1: Retrosynthetic analysis of brevipolide H (8) by Kumaraswamy.
Scheme 2: Attempt to synthesize brevipolide H (8) by Kumaraswamy. (R,R)-Noyori cat. = RuCl[N-(tosyl)-1,2-diph...
Scheme 3: Attempt to synthesize brevipolide H (8) by Kumaraswamy (continued).
Scheme 4: Retrosynthetic analysis of brevipolide H (8) by Hou.
Scheme 5: Synthesis ent-brevipolide H (ent-8) by Hou.
Scheme 6: Retrosynthetic analysis of brevipolide H (8) by Mohapatra.
Scheme 7: Attempt to synthesize brevipolide H (8) by Mohapatra.
Scheme 8: Attempt to synthesize brevipolide H (8) by Mohapatra (continued). (+)-(IPC)2-BCl = (+)-B-chloro-dii...
Scheme 9: Retrosynthetic analysis of brevipolide H (8) by Hou.
Scheme 10: Synthesis of brevipolide H (8) by Hou.
Scheme 11: Retrosynthetic analysis of brevipolide M (13) by Sabitha.
Scheme 12: Synthesis of brevipolide M (13) by Sabitha.
Scheme 13: Retrosynthetic analysis of brevipolides M (13) and N (14) by Sabitha.
Scheme 14: Synthesis of brevipolides M (13) and N (14) by Sabitha.
Beilstein J. Org. Chem. 2021, 17, 2302–2314, doi:10.3762/bjoc.17.148
Graphical Abstract
Figure 1: (I) DLS of PPM-NP4, MPM-NP2, PPM-NP4-TPP and MPM-NP2-TPP and (II) TEM of PPM-NP4-TPP and MPM-NP2-TPP...
Figure 2: Representative 31P NMR (top) and 1H NMR (bottom) spectrum of PP3-TPP conjugation product in D2O.
Scheme 1: Synthesis of TPP-based PISA particles based on zwitterionic 2-methacryloyloxyethyl phosphorylcholin...
Figure 3: Penetration of PPM-NP4-TPP and MPM-NP2-TPP micelles and fluorescence intensity profile on (A I, II)...
Figure 4: Growth effects of PPM-NP4-TPP and MPM-NP2-TPP on SW982 spheroids after 3 and 6 days of incubation (c...
Figure 5: Cell viability of SW982 spheroids after 6 days treatment with PPM-NP4, PPM-NP-TPP, MPM-NP2 and MPM-...
Figure 6: Cell localization of PPM-NP4-TPP (I) and MPM-NP2-TPP (II) into (A) mitochondria and (B) lysosomes u...
Figure 7: Cytotoxicity study of PPM-NP4-TPP and MPM-NP2-TPP on SW982 cells in relation to the concentration o...
Beilstein J. Org. Chem. 2021, 17, 2295–2301, doi:10.3762/bjoc.17.147
Graphical Abstract
Scheme 1: Chemical structures of queuine (Q base) and the hypermodified nucleoside queuosine (Q), the natural...
Scheme 2: Synthesis of compound 1 (m6preQ0) by cyclocondensation using a 4-methoxypyrimidine derivative resul...
Scheme 3: Synthesis of compound 3 following known procedures [31-33].
Scheme 4: The five-step synthesis of m6preQ1 2 from compound 3 required derivatization to make the intermedia...
Scheme 5: The synthesis of e6preQ1 (2a) and bn6preQ1 (2b) was performed in analogy to the route outlined in Scheme 4 ...
Beilstein J. Org. Chem. 2021, 17, 2260–2269, doi:10.3762/bjoc.17.144
Graphical Abstract
Figure 1: Proposed structural modifications to obtain triazole derivatives 1a, b and 2a–j.
Scheme 1: Synthetic route of the triazole derivatives 1a,b, and 2a–j.
Figure 2: Asymmetric unit representation of the 1,2,3-triazole derivative 2b. Displacement ellipsoids are dra...
Figure 3: Screening of the triazole derivatives of imatinib 1a,b, and 2a–j at concentrations of 1 μM and 10 μ...
Figure 4: Interaction maps of IMT, 2c, 2d, and 2g with the BCR-Abl-1 structure (PDB code: 3PYY), showing ster...
Beilstein J. Org. Chem. 2021, 17, 2209–2259, doi:10.3762/bjoc.17.143
Graphical Abstract
Scheme 1: Nickel-catalyzed cross-coupling versus C‒H activation.
Figure 1: Oxidative and reductive quenching cycles of a photocatalyst. [PC] = photocatalyst, A = acceptor, D ...
Scheme 2: Photoredox nickel-catalyzed C(sp3)–H arylation of dimethylaniline (1a).
Scheme 3: Photoredox nickel-catalyzed arylation of α-amino, α-oxy and benzylic C(sp3)‒H bonds with aryl bromi...
Figure 2: Proposed catalytic cycle for the photoredox-mediated HAT and nickel catalysis enabled C(sp3)‒H aryl...
Scheme 4: Photoredox arylation of α-amino C(sp3)‒H bonds with aryl iodides.
Figure 3: Proposed mechanism for photoredox nickel-catalyzed α-amino C‒H arylation with aryl iodides.
Scheme 5: Nickel-catalyzed α-oxy C(sp3)−H arylation of cyclic and acyclic ethers.
Figure 4: Proposed catalytic cycle for the C(sp3)−H arylation of cyclic and acyclic ethers.
Scheme 6: Photochemical nickel-catalyzed C–H arylation of ethers.
Figure 5: Proposed catalytic cycle for the nickel-catalyzed arylation of ethers with aryl bromides.
Scheme 7: Nickel-catalyzed α-amino C(sp3)‒H arylation with aryl tosylates.
Scheme 8: Arylation of α-amino C(sp3)‒H bonds by in situ generated aryl tosylates from phenols.
Scheme 9: Formylation of aryl chlorides through redox-neutral 2-functionalization of 1,3-dioxolane (13).
Scheme 10: Photochemical C(sp3)–H arylation via a dual polyoxometalate HAT and nickel catalytic manifold.
Figure 6: Proposed mechanism for C(sp3)–H arylation through dual polyoxometalate HAT and nickel catalytic man...
Scheme 11: Photochemical nickel-catalyzed α-hydroxy C‒H arylation.
Scheme 12: Photochemical synthesis of fluoxetine (21).
Scheme 13: Photochemical nickel-catalyzed allylic C(sp3)‒H arylation with aryl bromides.
Figure 7: Proposed mechanism for the photochemical nickel-catalyzed allylic C(sp3)‒H arylation with aryl brom...
Scheme 14: Photochemical C(sp3)‒H arylation by the synergy of ketone HAT catalysis and nickel catalysis.
Figure 8: Proposed mechanism for photochemical C(sp3)‒H arylation by the synergy of ketone HAT catalysis and ...
Scheme 15: Benzophenone- and nickel-catalyzed photoredox benzylic C–H arylation.
Scheme 16: Benzaldehyde- and nickel-catalyzed photoredox C(sp3)–H arylation.
Scheme 17: Photoredox and nickel-catalyzed enantioselective benzylic C–H arylation.
Figure 9: Proposed mechanism for the photoredox and nickel-catalyzed enantioselective benzylic C–H arylation.
Scheme 18: Photoredox nickel-catalyzed α-(sp3)‒H arylation of secondary benzamides with aryl bromides.
Scheme 19: Enantioselective sp3 α-arylation of benzamides.
Scheme 20: Nickel-catalyzed decarboxylative vinylation/C‒H arylation of cyclic oxalates.
Figure 10: Proposed mechanism for the nickel-catalyzed decarboxylative vinylation/C‒H arylation of cyclic oxal...
Scheme 21: C(sp3)−H arylation of bioactive molecules using mpg-CN photocatalysis and nickel catalysis.
Figure 11: Proposed mechanism for the mpg-CN/nickel photocatalytic C(sp3)–H arylation.
Scheme 22: Nickel-catalyzed synthesis of 1,1-diarylalkanes from alkyl bromides and aryl bromides.
Figure 12: Proposed mechanism for photoredox nickel-catalyzed C(sp3)–H alkylation via polarity-matched HAT.
Scheme 23: Photoredox nickel-catalyzed C(sp3)‒H alkylation via polarity-matched HAT.
Scheme 24: Benzaldehyde- and nickel-catalyzed photoredox C(sp3)‒H alkylation of ethers.
Scheme 25: Benzaldehyde- and nickel-catalyzed photoredox C(sp3)‒H alkylation of amides and thioethers.
Scheme 26: Photoredox and nickel-catalyzed C(sp3)‒H alkylation of benzamides with alkyl bromides.
Scheme 27: CzIPN and nickel-catalyzed C(sp3)‒H alkylation of ethers with alkyl bromides.
Figure 13: Proposed mechanism for the CzIPN and nickel-catalyzed C(sp3)‒H alkylation of ethers.
Scheme 28: Nickel/photoredox-catalyzed methylation of (hetero)aryl chlorides and acid chlorides using trimethy...
Figure 14: Proposed catalytic cycle for the nickel/photoredox-catalyzed methylation of (hetero)aryl chlorides ...
Scheme 29: Photochemical nickel-catalyzed C(sp3)–H methylations.
Scheme 30: Photoredox nickel catalysis-enabled alkylation of unactivated C(sp3)–H bonds with alkyl bromides.
Scheme 31: Photochemical C(sp3)–H alkenylation with alkenyl tosylates.
Scheme 32: Photoredox nickel-catalyzed hydroalkylation of internal alkynes.
Figure 15: Proposed mechanism for the photoredox nickel-catalyzed hydroalkylation of internal alkynes.
Scheme 33: Photoredox nickel-catalyzed hydroalkylation of activated alkynes with C(sp3)−H bonds.
Scheme 34: Allylation of unactivated C(sp3)−H bonds with allylic chlorides.
Scheme 35: Photochemical nickel-catalyzed α-amino C(sp3)–H allylation of secondary amides with trifluoromethyl...
Scheme 36: Photoredox δ C(sp3)‒H allylation of secondary amides with trifluoromethylated alkenes.
Scheme 37: Photoredox nickel-catalyzed acylation of α-amino C(sp3)‒H bonds of N-arylamines.
Figure 16: Proposed mechanism for the photoredox nickel-catalyzed acylation of α-amino C(sp3)–H bonds of N-ary...
Scheme 38: Photocatalytic α‑acylation of ethers with acid chlorides.
Figure 17: Proposed mechanism for the photocatalytic α‑acylation of ethers with acid chlorides.
Scheme 39: Photoredox and nickel-catalyzed C(sp3)‒H esterification with chloroformates.
Scheme 40: Photoredox nickel-catalyzed dehydrogenative coupling of benzylic and aldehydic C–H bonds.
Figure 18: Proposed reaction pathway for the photoredox nickel-catalyzed dehydrogenative coupling of benzylic ...
Scheme 41: Photoredox nickel-catalyzed enantioselective acylation of α-amino C(sp3)–H bonds with carboxylic ac...
Scheme 42: Nickel-catalyzed C(sp3)‒H acylation with N-acylsuccinimides.
Figure 19: Proposed mechanism for the nickel-catalyzed C(sp3)–H acylation with N-acylsuccinimides.
Scheme 43: Nickel-catalyzed benzylic C–H functionalization with acid chlorides 45.
Scheme 44: Photoredox nickel-catalyzed benzylic C–H acylation with N-acylsuccinimides 84.
Scheme 45: Photoredox nickel-catalyzed acylation of indoles 86 with α-oxoacids 87.
Scheme 46: Nickel-catalyzed aldehyde C–H functionalization.
Figure 20: Proposed catalytic cycle for the photoredox nickel-catalyzed aldehyde C–H functionalization.
Scheme 47: Photoredox carboxylation of methylbenzenes with CO2.
Figure 21: Proposed mechanism for the photoredox carboxylation of methylbenzenes with CO2.
Scheme 48: Decatungstate photo-HAT and nickel catalysis enabled alkene difunctionalization.
Figure 22: Proposed catalytic cycle for the decatungstate photo-HAT and nickel catalysis enabled alkene difunc...
Scheme 49: Diaryl ketone HAT catalysis and nickel catalysis enabled dicarbofunctionalization of alkenes.
Figure 23: Proposed catalytic mechanism for the diaryl ketone HAT catalysis and nickel catalysis enabled dicar...
Scheme 50: Overview of photoredox nickel-catalyzed C–H functionalizations.
Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139
Graphical Abstract
Figure 1: Chemical structure, numbering scheme, and resonance form of azulene.
Scheme 1: Synthesis of polyazulene-iodine (PAz-I2) and polyazulene-bromine (PAz-Br2) complexes.
Scheme 2: Synthesis of ‘true polyazulene’ 3 or 3’ by cationic polymerization.
Scheme 3: Synthesis of 1,3-polyazulene 5 by Yamamoto protocol.
Scheme 4: Synthesis of 4,7-dibromo-6-(n-alkyl)azulenes 12–14.
Scheme 5: Synthesis of (A) 4,7-diethynyl-6-(n-dodecyl)azulene (16) and (B) 4,7-polyazulene 17 containing an e...
Scheme 6: Synthesis of directly connected 4,7-polyazulenes 18–20.
Scheme 7: Synthesis of (A) tert-butyl N-(6-bromoazulen-2-yl)carbamate (27), (B) dimeric aminoazulene 29, and ...
Figure 2: Iminium zwitterionic resonance forms of poly[2(6)-aminoazulene] 31.
Scheme 8: Synthesis of poly{1,3-bis[2-(3-alkylthienyl)]azulene} 33–38.
Scheme 9: Synthesis of polymer ruthenium complexes 40–43.
Scheme 10: Synthesis of 4,7-polyazulenes 45 containing a thienyl linker.
Scheme 11: Synthesis of azulene-bithiophene 48 and azulene-benzothiadiazole 52 copolymers. Conditions: (a): (i...
Scheme 12: Synthesis of azulene-benzodithiophene copolymer 54 and azulene-bithiophene copolymer 56.
Scheme 13: Synthesis of (A) 5,5’-bis(trimethylstannyl)-3,3’-didodecyl-2,2’-bithiophene (60) and (B) azulene-bi...
Scheme 14: Synthesis of 1,3-bisborylated azulene 67.
Scheme 15: Synthesis of D–A-type azulene-DPP copolymers 69, 71, and 72. Conditions: (a) Pd(PPh3)4, K2CO3, Aliq...
Scheme 16: Synthesis of the key precursor TBAzDI 79.
Scheme 17: Synthesis of TBAzDI-based polymers 81 and 83. Conditions: (a) P(o-tol)3, Pd2(dba)3, PivOH, Cs2CO3, ...
Scheme 18: Synthesis of (A) 1,3-dibromo-2-arylazulene 92–98 and (B) 2-arylazulene-thiophene copolymers 99–101.
Scheme 19: Synthesis of (A) poly[2,7-(9,9-dialkylfluorenyl)-alt-(1’,3’-azulenyl)] 106–109, (B) 1,3-bis(7-bromo...
Scheme 20: Synthesis of azulene-fluorene copolymers 117–121 containing varying ratios of 1,3- and 4,7-connecte...
Scheme 21: Synthesis of (A) 2,6-dibromoazulene (125), (B) azulene-fluorene copolymer 126, and (C) azulene-fluo...
Scheme 22: Synthesis of 2-arylazulene-fluorene copolymers 131–134.
Scheme 23: Synthesis of azulene-fluorene-benzothiadiazole terpolymers 136–138.
Scheme 24: Synthesis of azulene-carbazole-benzothiadiazole-conjugated polymers 140–144.
Scheme 25: Synthesis of (A) azulene-2-yl methacrylate (146) and (B) the triazole-containing azulene methacryla...
Scheme 26: Synthesis of (A) azulene methacrylate polymer 151 and (B) triazole-containing azulene methacrylate ...
Scheme 27: Synthesis of azulene methyl methacrylate polymers 154, 155 (A and B) and azulene-sulfobetaine metha...
Beilstein J. Org. Chem. 2021, 17, 2102–2122, doi:10.3762/bjoc.17.137
Graphical Abstract
Scheme 1: Synthesis of 2,2’-bis(indole)borinic ester 3.
Scheme 2: Synthesis of 2,2’-bisindole NHC·boranes by an SEAr mechanism.
Scheme 3: Syntheses of indolyl amines through Buchwald–Hartwig cross coupling.
Scheme 4: Synthesis of 3,3’-bis(indolyl) ethers.
Scheme 5: C–H silylation of indoles.
Scheme 6: n-BuLi-mediated syntheses of bis(indol-3-yl)silanes.
Scheme 7: Acid-catalyzed syntheses of bis(indol-3-yl)silanes and mechanisms.
Scheme 8: B(C6F5)3 and Al(C6F5)3-catalyzed syntheses of bis(indol-3-yl)silanes reported by Han.
Scheme 9: Base-mediated syntheses of bis and tris(indol-2-yl)phosphines.
Scheme 10: Synthesis of bis(indol-2-yl)sulfides using SL2-type reagents.
Scheme 11: Synthesis of 2,3’- and 2,2’-bis(indolyl)sulfides using disulfides as substrates.
Scheme 12: Synthesis of diindol-2-ylsulfide (84) from 2-iodoindole (92) and thiourea.
Scheme 13: Synthesis of bis(indol-3-yl)sulfides using N-silylated 3-bromoindole 93.
Scheme 14: Fischer indole synthesis of bis(indol-3-yl)sulfides using thio diketones.
Scheme 15: Oxidative synthesis of bis(indol-3-yl)sulfides using indoles and elemental sulfur.
Scheme 16: Synthesis of bis(indol-3-yl)sulfides using sulfoxides as sulfur source.
Scheme 17: Syntheses of bis(indol-2-yl)selanes.
Scheme 18: Syntheses of bis(indol-3-yl)selanes.
Scheme 19: Synthesis of bis(indol-2-yl)tellane 147.
Scheme 20: Synthesis of tris(indolyl)borane 154.
Scheme 21: Synthesis of bis(indol-4-yl)amines 159.
Scheme 22: Synthesis of bis(indol-5-yl)amines.
Scheme 23: Synthesis of 6,5’/6,6’-bis(indolyl)amines.
Scheme 24: Synthesis of potent HIV-inhibitors 6,6’-bis(indolyl) ethers.
Scheme 25: Synthesis of bis(indol-7-yl) ether.
Scheme 26: Synthesis of di(indol-5-yl)sulfide (183).
Scheme 27: Syntheses of 2,2’-diformyl-7,7’-bis(indolyl)selenides.
Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131
Graphical Abstract
Figure 1: Examples of anthracene derivatives and their applications.
Scheme 1: Rhodium-catalyzed oxidative coupling reactions of arylboronic acids with internal alkynes.
Scheme 2: Rhodium-catalyzed oxidative benzannulation reactions of 1-adamantoyl-1-naphthylamines with internal...
Scheme 3: Gold/bismuth-catalyzed cyclization of o-alkynyldiarylmethanes.
Scheme 4: [2 + 2 + 2] Cyclotrimerization reactions with alkynes/nitriles in the presence of nickel and cobalt...
Scheme 5: Cobalt-catalyzed [2 + 2 + 2] cyclotrimerization reactions with bis(trimethylsilyl)acetylene (23).
Scheme 6: [2 + 2 + 2] Alkyne-cyclotrimerization reactions catalyzed by a CoCl2·6H2O/Zn reagent.
Scheme 7: Pd(II)-catalyzed sp3 C–H alkenylation of diphenyl carboxylic acids with acrylates.
Scheme 8: Pd(II)-catalyzed sp3 C–H arylation with o-tolualdehydes and aryl iodides.
Scheme 9: Alkylation of arenes with aromatic aldehydes in the presence of acetyl bromide and ZnBr2/SiO2.
Scheme 10: BF3·H2O-catalyzed hydroxyalkylation of arenes with aromatic dialdehyde 44.
Scheme 11: Bi(OTf)3-promoted Friedel–Crafts alkylation of triarylmethanes and aromatic acylals and of arenes a...
Scheme 12: Reduction of anthraquinones by using Zn/pyridine or Zn/NaOH reductive methods.
Scheme 13: Two-step route to novel substituted Indenoanthracenes.
Scheme 14: Synthesis of 1,8-diarylanthracenes through Suzuki–Miyaura coupling reaction in the presence of Pd-P...
Scheme 15: Synthesis of five new substituted anthracenes by using LAH as reducing agent.
Scheme 16: One-pot procedure to synthesize substituted 9,10-dicyanoanthracenes.
Scheme 17: Reduction of bromoanthraquinones with NaBH4 in alkaline medium.
Scheme 18: In(III)-catalyzed reductive-dehydration intramolecular cycloaromatization of 2-benzylic aromatic al...
Scheme 19: Acid-catalyzed cyclization of new O-protected ortho-acetal diarylmethanols.
Scheme 20: Lewis acid-mediated regioselective cyclization of asymmetric diarylmethine dipivalates and diarylme...
Scheme 21: BF3·OEt2/CF3SO3H-mediated cyclodehydration reactions of 2-(arylmethyl)benzaldehydes and 2-(arylmeth...
Scheme 22: Synthesis of 2,3,6,7-anthracenetetracarbonitrile (90) by double Wittig reaction followed by deprote...
Scheme 23: Homo-elongation protocol for the synthesis of substituted acene diesters/dinitriles.
Scheme 24: Synthesis of two new parental BN anthracenes via borylative cyclization.
Scheme 25: Synthesis of substituted anthracenes from a bifunctional organomagnesium alkoxide.
Scheme 26: Palladium-catalyzed tandem C–H activation/bis-cyclization of propargylic carbonates.
Scheme 27: Ruthenium-catalyzed C–H arylation of acetophenone derivatives with arenediboronates.
Scheme 28: Pd-catalyzed intramolecular cyclization of (Z,Z)-p-styrylstilbene derivatives.
Scheme 29: AuCl-catalyzed double cyclization of diiodoethynylterphenyl compounds.
Scheme 30: Iodonium-induced electrophilic cyclization of terphenyl derivatives.
Scheme 31: Oxidative photocyclization of 1,3-distyrylbenzene derivatives.
Scheme 32: Oxidative cyclization of 2,3-diphenylnaphthalenes.
Scheme 33: Suzuki-Miyaura/isomerization/ring closing metathesis strategy to synthesize benz[a]anthracenes.
Scheme 34: Green synthesis of oxa-aza-benzo[a]anthracene and oxa-aza-phenanthrene derivatives.
Scheme 35: Triple benzannulation of substituted naphtalene via a 1,3,6-naphthotriyne synthetic equivalent.
Scheme 36: Zinc iodide-catalyzed Diels–Alder reactions with 1,3-dienes and aroyl propiolates followed by intra...
Scheme 37: H3PO4-promoted intramolecular cyclization of substituted benzoic acids.
Scheme 38: Palladium-catalyzed intermolecular direct acylation of aromatic aldehydes and o-iodoesters.
Scheme 39: Cycloaddition/oxidative aromatization of quinone and β-enamino esters.
Scheme 40: ʟ-Proline-catalyzed [4 + 2] cycloaddition reaction of naphthoquinones and α,β-unsaturated aldehydes....
Scheme 41: Iridium-catalyzed [2 + 2 + 2] cycloaddition of a 1,2-bis(propiolyl)benzene derivative with alkynes.
Scheme 42: Synthesis of several anthraquinone derivatives by using InCl3 and molecular iodine.
Scheme 43: Indium-catalyzed multicomponent reactions employing 2-hydroxy-1,4-naphthoquinone (186), β-naphthol (...
Scheme 44: Synthesis of substituted anthraquinones catalyzed by an AlCl3/MeSO3H system.
Scheme 45: Palladium(II)-catalyzed/visible light-mediated synthesis of anthraquinones.
Scheme 46: [4 + 2] Anionic annulation reaction for the synthesis of substituted anthraquinones.
Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126
Graphical Abstract
Scheme 1: Schematic overview of transition metals studied in C–H activation processes.
Scheme 2: (A) Known biological activities related to benzimidazole-based compounds; (B and C) an example of a...
Scheme 3: (A) Known biological activities related to quinoline-based compounds; (B and C) an example of a sca...
Scheme 4: (A) Known biological activities related to sulfur-containing compounds; (B and C) an example of a s...
Scheme 5: (A) Known biological activities related to aminoindane derivatives; (B and C) an example of a scand...
Scheme 6: (A) Known biological activities related to norbornane derivatives; (B and C) an example of a scandi...
Scheme 7: (A) Known biological activities related to aniline derivatives; (B and C) an example of a titanium-...
Scheme 8: (A) Known biological activities related to cyclohexylamine derivatives; (B) an example of an intram...
Scheme 9: (A) Known biologically active benzophenone derivatives; (B and C) photocatalytic oxidation of benzy...
Scheme 10: (A) Known bioactive fluorine-containing compounds; (B and C) vanadium-mediated C(sp3)–H fluorinatio...
Scheme 11: (A) Known biologically active Lythraceae alkaloids; (B) synthesis of (±)-decinine (30).
Scheme 12: (A) Synthesis of (R)- and (S)-boehmeriasin (31); (B) synthesis of phenanthroindolizidines by vanadi...
Scheme 13: (A) Known bioactive BINOL derivatives; (B and C) vanadium-mediated oxidative coupling of 2-naphthol...
Scheme 14: (A) Known antiplasmodial imidazopyridazines; (B) practical synthesis of 41.
Scheme 15: (A) Gold-catalyzed drug-release mechanism using 2-alkynylbenzamides; (B and C) chromium-mediated al...
Scheme 16: (A) Examples of anti-inflammatory benzaldehyde derivatives; (B and C) chromium-mediated difunctiona...
Scheme 17: (A and B) Manganese-catalyzed chemoselective intramolecular C(sp3)–H amination; (C) late-stage modi...
Scheme 18: (A and B) Manganese-catalyzed C(sp3)–H amination; (C) late-stage modification of a leelamine deriva...
Scheme 19: (A) Known bioactive compounds containing substituted N-heterocycles; (B and C) manganese-catalyzed ...
Scheme 20: (A) Known indoles that present GPR40 full agonist activity; (B and C) manganese-catalyzed C–H alkyl...
Scheme 21: (A) Examples of known biaryl-containing drugs; (B and C) manganese-catalyzed C–H arylation through ...
Scheme 22: (A) Known zidovudine derivatives with potent anti-HIV properties; (B and C) manganese-catalyzed C–H...
Scheme 23: (A and B) Manganese-catalyzed C–H organic photo-electrosynthesis; (C) late-stage modification.
Scheme 24: (A) Example of a known antibacterial silylated dendrimer; (B and C) manganese-catalyzed C–H silylat...
Scheme 25: (A and B) Fe-based small molecule catalyst applied for selective aliphatic C–H oxidations; (C) late...
Scheme 26: (A) Examples of naturally occurring gracilioethers; (B) the first total synthesis of gracilioether ...
Scheme 27: (A and B) Selective aliphatic C–H oxidation of amino acids; (C) late-stage modification of proline-...
Scheme 28: (A) Examples of Illicium sesquiterpenes; (B) first chemical synthesis of (+)-pseudoanisatin (80) in...
Scheme 29: (A and B) Fe-catalyzed deuteration; (C) late-stage modification of pharmaceuticals.
Scheme 30: (A and B) Biomimetic Fe-catalyzed aerobic oxidation of methylarenes to benzaldehydes (PMHS, polymet...
Scheme 31: (A) Known tetrahydroquinolines with potential biological activities; (B and C) redox-selective Fe c...
Scheme 32: (A) Known drugs containing a benzofuran unit; (B and C) Fe/Cu-catalyzed tandem O-arylation to acces...
Scheme 33: (A) Known azaindolines that act as M4 muscarinic acetylcholine receptor agonists; (B and C) intramo...
Scheme 34: (A) Known indolinones with anticholinesterase activity; (B and C) oxidative C(sp3)–H cross coupling...
Scheme 35: (A and B) Cobalt-catalyzed C–H alkenylation of C-3-peptide-containing indoles; (C) derivatization b...
Scheme 36: (A) Cobalt-Cp*-catalyzed C–H methylation of known drugs; (B and C) scope of the o-methylated deriva...
Scheme 37: (A) Known lasalocid A analogues; (B and C) three-component cobalt-catalyzed C–H bond addition; (D) ...
Scheme 38: (A and B) Cobalt-catalyzed C(sp2)–H amidation of thiostrepton.
Scheme 39: (A) Known 4H-benzo[d][1,3]oxazin-4-one derivatives with hypolipidemic activity; (B and C) cobalt-ca...
Scheme 40: (A and B) Cobalt-catalyzed C–H arylation of pyrrole derivatives; (C) application for the synthesis ...
Scheme 41: (A) Known 2-phenoxypyridine derivatives with potent herbicidal activity; (B and C) cobalt-catalyzed...
Scheme 42: (A) Natural cinnamic acid derivatives; (B and C) cobalt-catalyzed C–H carboxylation of terminal alk...
Scheme 43: (A and B) Cobalt-catalyzed C–H borylation; (C) application to the synthesis of flurbiprofen.
Scheme 44: (A) Benzothiazoles known to present anticonvulsant activities; (B and C) cobalt/ruthenium-catalyzed...
Scheme 45: (A and B) Cobalt-catalyzed oxygenation of methylene groups towards ketone synthesis; (C) synthesis ...
Scheme 46: (A) Known anticancer tetralone derivatives; (B and C) cobalt-catalyzed C–H difluoroalkylation of ar...
Scheme 47: (A and B) Cobalt-catalyzed C–H thiolation; (C) application in the synthesis of quetiapine (153).
Scheme 48: (A) Known benzoxazole derivatives with anticancer, antifungal, and antibacterial activities; (B and...
Scheme 49: (A and B) Cobalt-catalyzed C–H carbonylation of naphthylamides; (C) BET inhibitors 158 and 159 tota...
Scheme 50: (A) Known bioactive pyrrolo[1,2-a]quinoxalin-4(5H)-one derivatives; (B and C) cobalt-catalyzed C–H ...
Scheme 51: (A) Known antibacterial cyclic sulfonamides; (B and C) cobalt-catalyzed C–H amination of propargyli...
Scheme 52: (A and B) Cobalt-catalyzed intramolecular 1,5-C(sp3)–H amination; (C) late-stage functionalization ...
Scheme 53: (A and B) Cobalt-catalyzed C–H/C–H cross-coupling between benzamides and oximes; (C) late-state syn...
Scheme 54: (A) Known anticancer natural isoquinoline derivatives; (B and C) cobalt-catalyzed C(sp2)–H annulati...
Scheme 55: (A) Enantioselective intramolecular nickel-catalyzed C–H activation; (B) bioactive obtained motifs;...
Scheme 56: (A and B) Nickel-catalyzed α-C(sp3)–H arylation of ketones; (C) application of the method using kno...
Scheme 57: (A and B) Nickel-catalyzed C(sp3)–H acylation of pyrrolidine derivatives; (C) exploring the use of ...
Scheme 58: (A) Nickel-catalyzed C(sp3)–H arylation of dioxolane; (B) library of products obtained from biologi...
Scheme 59: (A) Intramolecular enantioselective nickel-catalyzed C–H cycloalkylation; (B) product examples, inc...
Scheme 60: (A and B) Nickel-catalyzed C–H deoxy-arylation of azole derivatives; (C) late-stage functionalizati...
Scheme 61: (A and B) Nickel-catalyzed decarbonylative C–H arylation of azole derivatives; (C) application of t...
Scheme 62: (A and B) Another important example of nickel-catalyzed C–H arylation of azole derivatives; (C) app...
Scheme 63: (A and B) Another notable example of a nickel-catalyzed C–H arylation of azole derivatives; (C) lat...
Scheme 64: (A and B) Nickel-based metalorganic framework (MOF-74-Ni)-catalyzed C–H arylation of azole derivati...
Scheme 65: (A) Known commercially available benzothiophene-based drugs; (B and C) nickel-catalyzed C–H arylati...
Scheme 66: (A) Known natural tetrahydrofuran-containing substances; (B and C) nickel-catalyzed photoredox C(sp3...
Scheme 67: (A and B) Another notable example of a nickel-catalyzed photoredox C(sp3)–H alkylation/arylation; (...
Scheme 68: (A) Electrochemical/nickel-catalyzed C–H alkoxylation; (B) achieved scope, including three using na...
Scheme 69: (A) Enantioselective photoredox/nickel catalyzed C(sp3)–H arylation; (B) achieved scope, including ...
Scheme 70: (A) Known commercially available trifluoromethylated drugs; (B and C) nickel-catalyzed C–H trifluor...
Scheme 71: (A and B) Stereoselective nickel-catalyzed C–H difluoroalkylation; (C) late-stage functionalization...
Scheme 72: (A) Cu-mediated ortho-amination of oxalamides; (B) achieved scope, including derivatives obtained f...
Scheme 73: (A) Electro-oxidative copper-mediated amination of 8-aminoquinoline-derived amides; (B) achieved sc...
Scheme 74: (A and B) Cu(I)-mediated C–H amination with oximes; (C) derivatization using telmisartan (241) as s...
Scheme 75: (A and B) Cu-mediated amination of aryl amides using ammonia; (C) late-stage modification of proben...
Scheme 76: (A and B) Synthesis of purine nucleoside analogues using copper-mediated C(sp2)–H activation.
Scheme 77: (A) Copper-mediated annulation of acrylamide; (B) achieved scope, including the synthesis of the co...
Scheme 78: (A) Known bioactive compounds containing a naphthyl aryl ether motif; (B and C) copper-mediated eth...
Scheme 79: (A and B) Cu-mediated alkylation of N-oxide-heteroarenes; (C) late-stage modification.
Scheme 80: (A) Cu-mediated cross-dehydrogenative coupling of polyfluoroarenes and alkanes; (B) scope from know...
Scheme 81: (A) Known anticancer acrylonitrile compounds; (B and C) Copper-mediated cyanation of unactivated al...
Scheme 82: (A) Cu-mediated radiofluorination of 8-aminoquinoline-derived aryl amides; (B) achieved scope, incl...
Scheme 83: (A) Examples of natural β-carbolines; (B and C) an example of a zinc-catalyzed C–H functionalizatio...
Scheme 84: (A) Examples of anticancer α-aminophosphonic acid derivatives; (B and C) an example of a zinc-catal...
Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122
Graphical Abstract
Scheme 1: Mn-catalyzed late-stage fluorination of sclareolide (1) and complex steroid 3.
Figure 1: Proposed reaction mechanism of C–H fluorination by a manganese porphyrin catalyst.
Scheme 2: Late-stage radiofluorination of biologically active complex molecules.
Figure 2: Proposed mechanism of C–H radiofluorination.
Scheme 3: Late-stage C–H azidation of bioactive molecules. a1.5 mol % of Mn(TMP)Cl (5) was used. bMethyl acet...
Figure 3: Proposed reaction mechanism of manganese-catalyzed C–H azidation.
Scheme 4: Mn-catalyzed late-stage C–H azidation of bioactive molecules via electrophotocatalysis. a2.5 mol % ...
Figure 4: Proposed reaction mechanism of electrophotocatalytic azidation.
Scheme 5: Manganaelectro-catalyzed late-stage azidation of bioactive molecules.
Figure 5: Proposed reaction pathway of manganaelectro-catalyzed late-stage C–H azidation.
Scheme 6: Mn-catalyzed late-stage amination of bioactive molecules. a3 Å MS were used. Protonation with HBF4⋅...
Figure 6: Proposed mechanism of manganese-catalyzed C–H amination.
Scheme 7: Mn-catalyzed C–H methylation of heterocyclic scaffolds commonly found in small-molecule drugs. aDAS...
Scheme 8: Examples of late-stage C–H methylation of bioactive molecules. aDAST activation. bFor insoluble sub...
Scheme 9: A) Mn-catalyzed late-stage C–H alkynylation of peptides. B) Intramolecular late-stage alkynylative ...
Figure 7: Proposed reaction mechanism of Mn(I)-catalyzed C–H alkynylation.
Scheme 10: Late-stage Mn-catalyzed C–H allylation of peptides and bioactive motifs.
Scheme 11: Intramolecular C–H allylative cyclic peptide formation.
Scheme 12: Late-stage C–H glycosylation of tryptophan analogues.
Scheme 13: Late-stage C–H glycosylation of tryptophan-containing peptides.
Scheme 14: Late-stage C–H alkenylation of tryptophan-containing peptides.
Scheme 15: A) Late-stage C–H macrocyclization of tryptophan-containing peptides and B) traceless removal of py...
Beilstein J. Org. Chem. 2021, 17, 1727–1732, doi:10.3762/bjoc.17.121
Graphical Abstract
Scheme 1: Photocatalyzed aerobic oxidation of aromatic alcohols.
Scheme 2: Substrate scope. Reaction conditions as given in Table 1 (entry 1). Yields are isolated yields, average of...
Scheme 3: Selective oxidation of 3-bromobenzyl alcohol in the presence of 3-phenylpropanol. Compound 1af was ...
Figure 1: Mechanistic studies. (A): UV–vis spectra of the CeIV(OBn)Cln complex in CH3CN under blue light irra...
Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116
Graphical Abstract
Figure 1: Structure of DNA and PNA.
Figure 2: PNA binding modes: (A) PNA–dsDNA 1:1 triplex; (B) PNA–DNA–PNA strand-invasion triplex; (C) the Hoog...
Figure 3: Structure of P-form PNA–DNA–PNA triplex from reference [41]. (A) view in the major groove and (B) view ...
Figure 4: Structures of backbone-modified PNA.
Figure 5: Structures of PNA having α- and γ-substituted backbones.
Figure 6: Structures of modified nucleobases in PNA to improve Hoogsteen hydrogen bonding to guanine and aden...
Figure 7: Proposed hydrogen bonding schemes for modified PNA nucleobases designed to recognize pyrimidines or...
Figure 8: Modified nucleobases to modulate Watson–Crick base pairing and chemically reactive crosslinking PNA...
Figure 9: Examples of triplets formed by Janus-wedge PNA nucleobases (blue). R1 denotes DNA, RNA, or PNA back...
Figure 10: Examples of fluorescent PNA nucleobases. R1 denotes DNA, RNA, or PNA backbones.
Figure 11: Endosomal entrapment and escape pathways of PNA and PNA conjugates.
Figure 12: (A) representative cell-penetrating peptides (CPPs), (B) conjugation designs and linker chemistries....
Figure 13: Proposed delivery mode by pHLIP-PNA conjugates (A) the transmembrane section of pHLIP interacting w...
Figure 14: Structures of modified penetratin CPP conjugates with PNA linked through either disulfide (for stud...
Figure 15: Chemical structure of C9–PNA, a stable amphipathic (cyclic-peptide)–PNA conjugate.
Figure 16: Structures of PNA conjugates with a lipophilic triphenylphosphonium cation (TPP–PNA) through (A) th...
Figure 17: Structures of (A) chloesteryl–PNA, (B) cholate–PNA and (C) cholate–PNA(cholate)3.
Figure 18: Structures of PNA–GalNAc conjugates (A) (GalNAc)2K, (B) triantennary (GalNAc)3, and (C) trivalent (...
Figure 19: Vitamin B12–PNA conjugates with different linkages.
Figure 20: Structures of (A) neomycin B, (B) PNA–neamine conjugate, and (C) PNA–neosamine conjugate.
Figure 21: PNA clamp (red) binding to target DNA containing a mixture of sequences (A) PNA binds with higher a...
Figure 22: Rolling circle amplification using PNA openers (red) to invade a dsDNA target forming a P-loop. A p...
Figure 23: Molecular beacons containing generic fluorophores (Fl) and quenchers (Q) recognizing a complementar...
Figure 24: (A) Light-up fluorophores such as thiazole orange display fluorescence enhancement upon binding to ...
Figure 25: Templated fluorogenic detection of oligonucleotides using two PNAs. (A) Templated FRET depends on h...
Figure 26: Lateral flow devices use a streptavidin labeled strip on nitrocellulose paper to anchor a capture P...
Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114
Graphical Abstract
Figure 1: Some significant triazole derivatives [8,23-27].
Scheme 1: A general comparison between synthetic routes for disubstituted 1,2,3-triazole derivatives and full...
Scheme 2: Synthesis of formyltriazoles 3 from the treatment of α-bromoacroleins 1 with azides 2.
Scheme 3: A probable mechanism for the synthesis of formyltriazoles 5 from the treatment of α-bromoacroleins 1...
Scheme 4: Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 8 from the reaction of aryl azides 7 with enamino...
Scheme 5: Proposed mechanism for the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles from the reaction of a...
Scheme 6: Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 11 from the reaction of primary amines 10 with 1,...
Scheme 7: The proposed mechanism for the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 11 from the reacti...
Scheme 8: Synthesis of fully decorated 1,2,3-triazoles 19 containing a sulfur-based side chain.
Scheme 9: Mechanism for the formation of fully decorated 1,2,3-triazoles 19 containing a sulfur-based side ch...
Scheme 10: Synthesis of fully decorated 1,2,3-triazole compounds 25 through the regioselective addition and cy...
Scheme 11: A reasonable mechanism for the synthesis of fully decorated 1,2,3-triazole compounds 25 through the...
Scheme 12: Synthesis of 1,4,5-trisubstituted glycosyl-containing 1,2,3-triazole derivatives 30 from the reacti...
Scheme 13: Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 34 via intramolecular cyclization reaction of ket...
Scheme 14: Synthesis of fully decorated 1,2,3-triazoles 38 from the reaction of aldehydes 35, amines 36, and α...
Scheme 15: A reasonable mechanism for the synthesis of fully decorated 1,2,3-triazoles 38 from the reaction of...
Scheme 16: Synthesis of functionally rich double C- and N-vinylated 1,2,3-triazoles 45 and 47.
Scheme 17: Synthesis of disubstituted 4-chloro-, 4-bromo-, and 4-iodo-1,2,3-triazoles 50.
Scheme 18: a) A general route for SPAAC in polymer chemistry and b) synthesis of a novel pH-sensitive polymeri...
Scheme 19: Synthesis of 5-allenyl-1,2,3-triazoles 60 by the treatment of alkynes 57, azides 58, and propargyli...
Scheme 20: A reasonable mechanism for the synthesis of 5-allenyl-1,2,3-triazoles 60 by the treatment of alkyne...
Scheme 21: Synthesis of 5‐alkynyl-1,2,3-triazoles 69.
Scheme 22: A reasonable mechanism for the synthesis of 5‐alkynyl-1,2,3-triazoles 69.
Scheme 23: Synthesis of sulfur-cycle-fused 1,2,3-triazoles 75 and 77.
Scheme 24: A reasonable mechanism for the synthesis of sulfur-cycle-fused 1,2,3‐triazoles 75 and 77.
Scheme 25: Synthesis of 5-selanyltriazoles 85 from the reaction of ethynylstibanes 82, organic azides 83, and ...
Scheme 26: A mechanism for the synthesis of 5-selanyltriazoles 85 from the reaction of ethynylstibanes 82, org...
Scheme 27: Synthesis of trisubstituted triazoles containing an Sb substituent at position C5 in 93 and 5-unsub...
Scheme 28: Synthesis of asymmetric triazole disulfides 98 from disulfide-containing tert-butyltosyl disulfide 97...
Scheme 29: A mechanism for the synthesis of asymmetric triazole disulfides 98 from disulfide-containing tert-bu...
Scheme 30: Synthesis of triazole-fused sultams 104.
Scheme 31: Synthesis of 1,2,3-triazole-fused tricyclic heterocycles 106.
Scheme 32: A reasonable mechanism for the synthesis of 1,2,3-triazole-fused tricyclic heterocycles 106.
Scheme 33: Synthesis of 5-aryl-substituted 1,2,3-triazole derivatives 112.
Scheme 34: A reasonable mechanism for the synthesis of 5-aryl-substituted 1,2,3-triazole derivatives 112.
Scheme 35: Synthesis of 1,4,5-trisubstituted 1,2,3-triazole-5-carboxamides 119.
Scheme 36: A probable mechanism for the synthesis of 1,4,5-trisubstituted 1,2,3-triazole-5-carboxamides 119.
Scheme 37: Synthesis of fully decorated triazoles 125 via the Pd/C-catalyzed arylation of disubstituted triazo...
Scheme 38: Synthesis of triazolo[1,5-a]indolones 131.
Scheme 39: Synthesis of unsymmetrically substituted triazole-fused enediyne systems 135 and 5-aryl-4-ethynyltr...
Scheme 40: Synthesis of Pd/Cu-BNP 139 and application of 139 in the synthesis of polycyclic triazoles 142.
Scheme 41: A probable mechanism for the synthesis of polycyclic triazoles 142.
Scheme 42: Synthesis of highly functionalized 1,2,3-triazole-fused 5-, 6-, and 7-membered rings 152–154.
Scheme 43: A probable mechanism for the synthesis of highly functionalized 1,2,3-triazole-fused 5-, 6-, and 7-...
Scheme 44: Synthesis of fully functionalized 1,2,3-triazolo-fused chromenes 162, 164, and 166 via the intramol...
Scheme 45: Ru-catalyzed synthesis of fully decorated triazoles 172.
Scheme 46: Synthesis of 4-cyano-1,2,3-triazoles 175.
Scheme 47: Synthesis of functionalized triazoles from the reaction of 1-alkyltriazenes 176 and azides 177 and ...
Scheme 48: Mechanism for the synthesis of functionalized triazoles from the reaction of 1-alkyltriazenes 176 a...
Beilstein J. Org. Chem. 2021, 17, 1591–1599, doi:10.3762/bjoc.17.113
Graphical Abstract
Figure 1: Assembly of 3-methyleneisoindolin-1-one via 3d transition metal-mediated/catalyzed oxidative C−H/N−...
Scheme 1: Copper-mediated oxidative C−H/N−H functionalization of hydrazides 1 with ethynylbenzene (2a).
Scheme 2: Copper-mediated oxidative C−H/N−H functionalization of 1 with alkynes 2.
Scheme 3: Decaboxylative C−H/N−H activation and cleavage of the directing group.
Scheme 4: Summary of key mechanistic findings.
Scheme 5: Proposed reaction pathway.
Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112
Graphical Abstract
Figure 1: Some examples of natural products and drugs containing quaternary carbon centers.
Scheme 1: Simplified mechanism for olefin hydrofunctionalization using an electrophilic transition metal as a...
Scheme 2: Selected examples of quaternary carbon centers formed by the intramolecular hydroalkylation of β-di...
Scheme 3: Control experiments and the proposed mechanism for the Pd(II)-catalyzed intermolecular hydroalkylat...
Scheme 4: Intermolecular olefin hydroalkylation of less reactive ketones under Pd(II) catalysis using HCl as ...
Scheme 5: A) Selected examples of Pd(II)-mediated quaternary carbon center synthesis by intermolecular hydroa...
Scheme 6: Selected examples of quaternary carbon center synthesis by gold(III) catalysis. This is the first r...
Scheme 7: Selected examples of inter- (A) and intramolecular (B) olefin hydroalkylations promoted by a silver...
Scheme 8: A) Intermolecular hydroalkylation of N-alkenyl β-ketoamides under Au(I) catalysis in the synthesis ...
Scheme 9: Asymmetric pyrrolidine synthesis through intramolecular hydroalkylation of α-substituted N-alkenyl ...
Scheme 10: Proposed mechanism for the chiral gold(I) complex promotion of the intermolecular olefin hydroalkyl...
Scheme 11: Selected examples of carbon quaternary center synthesis by gold and evidence of catalytic system pa...
Scheme 12: Synthesis of a spiro compound via an aza-Michael addition/olefin hydroalkylation cascade promoted b...
Scheme 13: A selected example of quaternary carbon center synthesis using an Fe(III) salt as a catalyst for th...
Scheme 14: Intermolecular hydroalkylation catalyzed by a cationic iridium complex (Fuji (2019) [47]).
Scheme 15: Generic example of an olefin hydrofunctionalization via MHAT (Shenvi (2016) [51]).
Scheme 16: The first examples of olefin hydrofunctionalization run under neutral conditions (Mukaiyama (1989) [56]...
Scheme 17: A) Aryl olefin dimerization catalyzed by vitamin B12 and triggered by HAT. B) Control experiment to...
Scheme 18: Generic example of MHAT diolefin cycloisomerization and possible competitive pathways. Shenvi (2014...
Scheme 19: Selected examples of the MHAT-promoted cycloisomerization reaction of unactivated olefins leading t...
Scheme 20: Regioselective carbocyclizations promoted by an MHAT process (Norton (2008) [76]).
Scheme 21: Selected examples of quaternary carbon centers synthetized via intra- (A) and intermolecular (B) MH...
Scheme 22: A) Proposed mechanism for the Fe(III)/PhSiH3-promoted radical conjugate addition between olefins an...
Scheme 23: Examples of cascade reactions triggered by HAT for the construction of trans-decalin backbone uniti...
Scheme 24: A) Selected examples of the MHAT-promoted radical conjugate addition between olefins and p-quinone ...
Scheme 25: A) MHAT triggered radical conjugate addition/E1cB/lactonization (in some cases) cascade between ole...
Scheme 26: A) Spirocyclization promoted by Fe(III) hydroalkylation of unactivated olefins. B) Simplified mecha...
Scheme 27: A) Selected examples of the construction of a carbon quaternary center by the MHAT-triggered radica...
Scheme 28: Hydromethylation of unactivated olefins under iron-mediated MHAT (Baran (2015) [95]).
Scheme 29: The hydroalkylation of unactivated olefins via iron-mediated reductive coupling with hydrazones (Br...
Scheme 30: Selected examples of the Co(II)-catalyzed bicyclization of dialkenylarenes through the olefin hydro...
Scheme 31: Proposed mechanism for the bicyclization of dialkenylarenes triggered by a MHAT process (Vanderwal ...
Scheme 32: Enantioconvergent cross-coupling between olefins and tertiary halides (Fu (2018) [108]).
Scheme 33: Proposed mechanism for the Ni-catalyzed cross-coupling reaction between olefins and tertiary halide...
Scheme 34: Proposed catalytic cycles for a MHAT/Ni cross-coupling reaction between olefins and halides (Shenvi...
Scheme 35: Selected examples of the hydroalkylation of olefins by a dual catalytic Mn/Ni system (Shenvi (2019) ...
Scheme 36: A) Selected examples of quaternary carbon center synthesis by reductive atom transfer; TBC: 4-tert-...
Scheme 37: A) Selected examples of quaternary carbon centers synthetized by radical addition to unactivated ol...
Scheme 38: A) Selected examples of organophotocatalysis-mediated radical polyene cyclization via a PET process...
Scheme 39: A) Sc(OTf)3-mediated carbocyclization approach for the synthesis of vicinal quaternary carbon cente...
Scheme 40: Scope of the Lewis acid-catalyzed methallylation of electron-rich styrenes. Method A: B(C6F5)3 (5.0...
Scheme 41: The proposed mechanism for styrene methallylation (Oestreich (2019) [123]).
Beilstein J. Org. Chem. 2021, 17, 1490–1498, doi:10.3762/bjoc.17.105
Graphical Abstract
Scheme 1: Retrosynthetic analysis of heterocycles A and B.
Figure 1: Molecular structure of compound 3a, displacement parameters are drawn at 50%.
Scheme 2: Free-radical cyclization of N-protected and N-unprotected pyrroles 1a and 2.
Scheme 3: Synthesis of 2H-pyrido[2,1-a]pyrrolo[3,4-c]isoquinolin-4-ium bromide 8.
Scheme 4: Free-radical cyclization of dihalogeno-substituted salts 9 and 12.
Figure 2: Molecular structure of compound 13, displacement parameters are drawn at 50% probability level.
Scheme 5: N-alkylation of the base 6a.
Figure 3: Molecular structure of compound 17a, displacement parameters are drawn at 50% probability level.
Scheme 6: Isomerization of compounds 17a and 18a.
Scheme 7: N-Alkylation of compounds 18a and 19.