Search for "C–O bond" in Full Text gives 152 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172
Graphical Abstract
Scheme 1: Syntheses of C4-substituted diethyl 2,6-pyridinedicarbamates 4, passing hazardous and explosive dia...
Scheme 2: Synthesis of 1-deazaguanine (11) described by Markees and Kidder in 1956 [18].
Scheme 3: Synthesis of 1-deazaguanine (11) described by Gorton and Shive in 1957 [19].
Scheme 4: Six-step synthesis of 1-deazaguanine (11). Abbreviations: p-toluenesulfonic acid (TsOH), 4-(dimethy...
Scheme 5: 1-Deazahypoxanthine (30) synthesis described by Kubo and Hirao in 2019 [29]. For reason of simplicity o...
Scheme 6: Synthesis of 1-deazahypoxanthine (30).
Beilstein J. Org. Chem. 2022, 18, 1107–1115, doi:10.3762/bjoc.18.113
Graphical Abstract
Figure 1: Structures of cattleyaisoflavones A (1), B (2), C (3), and daidzein (4).
Figure 2: a) The culture in ISP-2 liquid did not produce 1–3, while feeding with 4 restored the production (a...
Figure 3: CYP158C1 dimerizes 4 to form dimers 2 and 5 in vitro (analytical method B, 254 nm). Control conditi...
Scheme 1: a) Compatible and b) incompatible substrates of CYP158C1. Products were identified using analytical...
Scheme 2: Proposed mechanism of CYP158C1-mediated dimerization of isoflavones.
Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93
Graphical Abstract
Scheme 1: Reuben G. Jones synthesis of 2-hydroxypyrazines.
Scheme 2: Four hypothetical reaction intermediates.
Figure 1: ORTEP depiction of compound 4{1,2}.
Scheme 3: Suggested mechanism for the Reuben G. Jones synthesis of 2-hydroxypyrazines.
Scheme 4: Tetraethylammonium hydroxide-mediated condensation of glyoxal (1{3}), methylglyoxal (1{4}), or 2-(4...
Beilstein J. Org. Chem. 2022, 18, 769–780, doi:10.3762/bjoc.18.77
Graphical Abstract
Scheme 1: Early studies concerning cyclopropene cycloadditions to azomethine ylides and cycloaddition reactio...
Scheme 2: The pilot experiment aimed at studying the cycloaddition reaction between the protonated form of Ru...
Scheme 3: Synthesis of meso-3'-azadispiro[indene-2,2'-bicyclo[3.1.0]hexane-4',2''-indene] derivatives 3b–g vi...
Figure 1: ORTEP representation of the molecular structure of 3e.
Scheme 4: The reaction of protonated Ruhemann's purple (1) with 3-methyl-3-phenylcyclopropene (2j).
Scheme 5: Attempts to carry out the cycloaddition reactions between 3,3-disubstituted cyclopropenes 2k,l and ...
Scheme 6: The reactions of protonated Ruhemann's purple (1) with unstable cyclopropenes 2m–p.
Scheme 7: The acid–base reaction of Ruhemann's purple with hydrochloric acid and relative Gibbs free energy c...
Scheme 8: Plausible mechanism of the 1,3-DC reaction of protonated Ruhemann's purple (1) with 3-methyl-3-phen...
Scheme 9: Plausible mechanism of the 1,3-DC reaction of protonated Ruhemann's purple (1) with 1-chloro-2-phen...
Beilstein J. Org. Chem. 2022, 18, 533–538, doi:10.3762/bjoc.18.55
Graphical Abstract
Figure 1: Previously reported transformations of DAS (1) and their unusual dimerization investigated in this ...
Scheme 1: The result of Rh(II)-catalyzed decomposition of DAS 1r.
Scheme 2: Plausible mechanism for the formation of dimer 2a and indene 3a through the Rh(II)-catalyzed decomp...
Figure 2: Cytotoxicity of N-alkyl-substituted dibenzoazulenodipyrroles 2 against the A549 human lung adenocar...
Beilstein J. Org. Chem. 2021, 17, 2932–2938, doi:10.3762/bjoc.17.202
Graphical Abstract
Figure 1: Uncaging of peptide backbone N–H bonds from Chan–Lam-type modification.
Figure 2: Photocleavage of compounds 1 and 6 under basic conditions. Yield of products was calculated from cr...
Figure 3: (a) Photocleavage of compound 6 under acidic conditions. Yields determined by 1H NMR using residual...
Figure 4: Preparation and hydrolysis kinetics (inset) of N-formyl product 11. Dashed line: first-order decay ...
Figure 5: Proposed mechanism for the formation of aldehyde 3 and N-formyl product 8.
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, 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, 2321–2328, doi:10.3762/bjoc.17.150
Graphical Abstract
Figure 1: Representation of bioactive molecules and applications.
Scheme 1: Synthetic methodologies for 3-monohalooxindoles.
Scheme 2: Substrate scope of the acidolysis of isatin-derived phosphates 2 with hydrochloric acid. Standard r...
Scheme 3: Substrate scope of the acidolysis of isatin-derived phosphates 2 with hydrobromic acid. Standard re...
Scheme 4: Reduction of the substrates 2 to the corresponding oxindoles 5.
Scheme 5: Plausible reaction mechanism.
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, 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, 1509–1517, doi:10.3762/bjoc.17.108
Graphical Abstract
Figure 1: Structures of exemplary benzo- and heteroaromatic fused 1,4-quinone drugs and natural products.
Scheme 1: First [3 + 2]-cycloaddition of 1,4-naphthoquinone (1a) with intermediate nitrile imine 2, generated...
Scheme 2: Selected applications of trifluoroacetonitrile imines 7 in the synthesis of S-containing 5- and 6-m...
Scheme 3: Synthesis of [3 + 2]-cycloadducts 9a–l derived from CF3-substituted nitrile imines 7a–h and 1,4-qui...
Figure 2: X-ray structure of 3-trifluoromethylpyrazole derivative 9d. The labeling scheme of the asymmetric u...
Scheme 4: Thermal elimination of MeOH from the initial [3 + 2]-cycloadduct of 1d and nitrile imine 7d generat...
Scheme 5: Formation of the thermally stable, initially formed [3 + 2]-cycloadduct 10c obtained from 1e and ni...
Figure 3: Electronic absorption spectra for selected a) naphthoquinone-derived (9c, 9d, 9g) and b) anthraquin...
Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53
Graphical Abstract
Figure 1: Potential classification of plastic recycling processes. The area covered by the present review is ...
Figure 2: EG produced during glycolytic depolymerisation of PET using DEG + DPG as solvent and titanium(IV) n...
Scheme 1: Simplified representation of the conversion of 1,4-PBD to C16–C44 macrocycles using Ru metathesis c...
Figure 3: Main added-value monomers obtainable by catalytic depolymerisation of PET via chemolytic methods.
Scheme 2: Hydrogenolytic depolymerisation of PET by ruthenium complexes.
Scheme 3: Depolymerisation of PET via catalytic hydrosilylation by Ir(III) pincer complex.
Scheme 4: Catalytic hydrolysis (top) and methanolysis (bottom) reactions of PET.
Scheme 5: Depolymerisation of PET by glycolysis with ethylene glycol.
Figure 4: Glycolysis of PET: evolution of BHET yield over time, with and without zinc acetate catalyst (196 °...
Scheme 6: Potential activated complex for the glycolysis reaction of PET catalysed by metallated ILs and evol...
Scheme 7: One-pot, two-step process for PET repurposing via chemical recycling.
Scheme 8: Synthetic routes to PLA.
Scheme 9: Structures of the zinc molecular catalysts used for PLA-methanolysis in various works. a) See [265], b) ...
Scheme 10: Depolymerisation of PLLA by Zn–N-heterocyclic carbene complex.
Scheme 11: Salalen ligands.
Scheme 12: Catalytic hydrogenolysis of PLA.
Scheme 13: Catalytic hydrosilylation of PLA.
Scheme 14: Hydrogenative depolymerisation of PBT and PCL by molecular Ru catalysts.
Scheme 15: Glycolysis reaction of PCT by diethylene glycol.
Scheme 16: Polymerisation–depolymerisation cycle of 3,4-T6GBL.
Scheme 17: Polymerisation–depolymerisation cycle of 2,3-HDB.
Scheme 18: Hydrogenative depolymerisation of PBPAC by molecular Ru catalysts.
Scheme 19: Catalytic hydrolysis (top), alcoholysis (middle) and aminolysis (bottom) reactions of PBPAC.
Scheme 20: Hydrogenative depolymerisation of PPC (top) and PEC (bottom) by molecular Ru catalysts.
Scheme 21: Polymerisation-depolymerisation cycle of BEP.
Scheme 22: Hydrogenolysis of polyamides using soluble Ru catalysts.
Scheme 23: Catalytic depolymerisation of epoxy resin/carbon fibres composite.
Scheme 24: Depolymerisation of polyethers with metal salt catalysts and acyl chlorides.
Scheme 25: Proposed mechanism for the iron-catalysed depolymerisation reaction of polyethers. Adapted with per...
Beilstein J. Org. Chem. 2021, 17, 410–419, doi:10.3762/bjoc.17.37
Graphical Abstract
Scheme 1: Synthetic pathways for the synthesis of 6-substituted 2-triazolylpurine derivatives IV.
Scheme 2: Synthesis of 2,6-bistriazolylpurine derivatives 2a–c.
Scheme 3: Synthesis of 6-alkyloxy-2-triazolylpurine derivatives 3a–f.
Scheme 4: Synthesis of 6-alkyloxy-2-triazolylpurine nucleosides 3g–j.
Scheme 5: 2,6-Bistriazolylpurine derivatives in SNAr reactions with H2O/HO− as nucleophiles.
Scheme 6: Synthesis of C6-substituted 2-triazolylpurine derivatives 5.
Figure 1: Possible tautomeric structures of compounds 5a–d.
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, 2757–2768, doi:10.3762/bjoc.16.226
Graphical Abstract
Scheme 1: RCEYM with Ru and Mo catalysts.
Scheme 2: Beneficial effect of ethene atmosphere.
Scheme 3: Enantioselective dienyne metathesis [21].
Scheme 4: Diastereoselective endiyne metathesis [31].
Figure 1: Oxaenediynes considered for the study of desymmetrizing RCEYM.
Scheme 5: Synthesis of hepta-1,6-diyn-4-ol (4a).
Scheme 6: Protection of hepta-1,6-diyn-4-ol (4a).
Scheme 7: Alkylation of the protected diynols 7a and 8a.
Scheme 8: Deprotection of protected diynols 7b, 7c and 8b–d.
Scheme 9: Synthesis of the oxaenediynes 2 and 9 bearing an allyl or a methallyl group.
Scheme 10: Synthesis of oxaenediynes 2e and 2f bearing ester or silyl groups.
Scheme 11: Synthesis of alkadiynyl acrylates 10 and methacrylates 11.
Figure 2: The ruthenium precatalysts employed.
Scheme 12: RCEYM of oxaenediynes 2.
Figure 3: Examples of side products of CM with ethene.
Scheme 13: Attempted RCEYM of oxaenediynes 9, alkadiynyl acrylates 10 and methacrylates 11.
Scheme 14: Diels–Alder reaction of dihydropyran 12b with N-phenylmaleimide (13).
Figure 4: The four possible diastereoisomers of hexahydropyranoisoindole 14.
Figure 5: Conformations of dihydropyran 12b.
Figure 6: The two most stable s-trans (left) and s-cis (right) conformations of dihydropyran 12b.
Figure 7: The two most stable transition states endo-trans 15B and exo-cis 15C (hydrogens are omitted for cla...
Figure 8: PES of the Diels–Alder reaction of dihydropyran 12b and maleimide 13.
Beilstein J. Org. Chem. 2020, 16, 2663–2670, doi:10.3762/bjoc.16.216
Graphical Abstract
Figure 1: The natural product piperine (1) is the inspiration for this work; the crystal structure is shown [14]....
Scheme 1: The attempted synthesis of 6 (a diastereoisomer of 2) via a one-step 1,2-difluorination reaction [24]. ...
Scheme 2: The attempted synthesis of 2 via a stepwise fluorination approach (ether series). THF = tetrahydrof...
Scheme 3: Synthesis of compound 2 via a stepwise fluorination approach (ester series). DIC = diisopropylcarbo...
Figure 2: Conformational analysis of 2 by DFT and NMR. The numbering scheme for NMR spins is given on structu...
Figure 3: Analog 2 has greater stability to UV light than does piperine (1).
Figure 4: Biological activity of piperine (1) and derivative 2. (a) Inihbition of AChE by 1 (IC50 >1000 μM) a...
Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186
Graphical Abstract
Figure 1: Representation of corannulene (1) and sumanene (2), the subunits of fullerene (C60).
Scheme 1: Mehta’s unsuccessful effort for the synthesis of sumanene scaffold 2.
Scheme 2: First synthesis of sumanene 2 by Sakurai et al. from norbornadiene 10.
Scheme 3: Synthesis of trimethylsumanene 28 from easily accessible norbornadiene (10).
Scheme 4: Generation of anions 29–31 and the preparation of tris(trimethylsilyl)sumanene 32.
Scheme 5: Synthesis of tri- and hexa-substituted sumanene derivatives.
Scheme 6: Synthesis of bowl-shaped π-extended sumanene derivatives 37a–f.
Scheme 7: Synthesis of monooxasumanene 38, trioxosumanene 40 along with imination of them.
Scheme 8: Synthesis of trimethylsumanenetrione 46 and exo-functionalized products 45a,b.
Scheme 9: Synthesis of bisumanenylidene 47 and sumanene dimer 48 from 2.
Scheme 10: The mono-substitution of 2 to generate diverse mono-sumanene derivatives 49a–d.
Scheme 11: Synthesis of sumanene building block 53 useful for further extension.
Scheme 12: Synthesis of hexafluorosumanene derivative 55 by Sakurai and co-workers.
Scheme 13: Preparation of sumanene-based carbene 60 and its reaction with cyclohexane.
Scheme 14: Barton–Kellogg reaction for the synthesis of sterically hindered alkenes.
Scheme 15: Synthesis of hydroxysumanene 68 by employing Baeyer–Villiger oxidation.
Scheme 16: Synthesis of sumanene derivatives having functionality at an internal carbon.
Scheme 17: Mechanism for nucleophilic substitution reaction at the internal carbon.
Scheme 18: Synthesis of diverse monosubstituted sumanene derivatives.
Scheme 19: Synthesis of di- and trisubstituted sumanene derivatives from sumanene (2).
Scheme 20: Preparation of monochlorosumanene 88 and hydrogenation of sumanene (2).
Scheme 21: The dimer 90 and bissumanenyl 92 achieved from halosumannes.
Scheme 22: Pyrenylsumanene 93 involving the Suzuki-coupling as a key transformation.
Scheme 23: Synthesis of various hexaarylsumanene derivatives using the Suzuki-coupling reaction.
Scheme 24: Synthesis of hexasubstituted sumanene derivatives 96 and 97.
Scheme 25: Synthesis of thioalkylsumanenes via an aromatic nucleophilic substitution reaction.
Scheme 26: Synthesis of tris(ethoxycarbonylethenyl)sumanene derivative 108.
Scheme 27: Synthesis of ferrocenyl-based sumanene derivatives.
Scheme 28: Synthesis of sumanenylferrocene architectures 118 and 119 via Negishi coupling.
Scheme 29: Diosmylation and the synthesis of phenylboronate ester 121 of sumanene.
Scheme 30: Synthesis of the iron-complex of sumanene.
Scheme 31: Synthesis of tri- and mononuclear sumanenyl zirconocene complexes.
Scheme 32: Synthesis of [CpRu(η6-sumanene)]PF6.
Scheme 33: Preparation of sumanene-based porous coordination networks 127 (spherical tetramer units) and 128 (...
Scheme 34: Synthesis of sumanenylhafnocene complexes 129 and 130.
Scheme 35: Synthesis of 134 and 135 along with PdII coordination complex 136.
Scheme 36: Synthesis of alkali metals sumanene complex K7(C21H102−)2(C21H93−)·8THF (137) containing di- and tr...
Scheme 37: The encapsulation of a Cs+ ion between two sumanenyl anions.
Scheme 38: Synthesis of monothiasumanene 140 and dithiasumanene 141 from 139.
Scheme 39: Synthesis of trithiasumanene 151 by Otsubo and his co-workers.
Scheme 40: Synthesis of trithiasumanene derivatives 155 and 156.
Scheme 41: Synthetic route towards hexathiolated trithiasumanenes 158.
Scheme 42: Synthesis of triselenasumanene 160 by Shao and teammates.
Scheme 43: Synthesis of tritellurasumanene derivatives from triphenylene skeletons.
Scheme 44: Synthesis of pyrazine-fused sumanene architectures through condensation reaction.
Scheme 45: Treatment of the trichalcogenasumanenes with diverse oxidative reagents.
Scheme 46: Ring-opening reaction with H2O2 and oxone of heterasumanenes 178 and 179.
Scheme 47: Synthesis of polycyclic compounds from sumanene derivatives.
Scheme 48: Synthesis of diimide-based heterocycles reported by Shao’s and co-workers.
Scheme 49: Synthesis of pristine trichalcogenasumanenes, 151, 205, and 206.
Scheme 50: Synthesis of trichalcogenasumanenes via hexaiodotriphenylene precursor 208.
Scheme 51: Synthesis of trisilasumanenes 214 and 215.
Scheme 52: Synthesis of trisilasumanene derivatives 218 and 219.
Scheme 53: Synthesis of novel trigermasumanene derivative 223.
Scheme 54: An attempt towards the synthesis of tristannasumanene derivative 228.
Scheme 55: Synthesis of triphosphasumanene trisulfide 232 from commercially available 229.
Scheme 56: The doping of sumanene derivatives with chalcogens (S, Se, Te) and phosphorus.
Scheme 57: Synthesis of heterasumanene containing three different heteroatoms.
Scheme 58: Synthesis of trichalcogenasumanene derivatives 240 and 179.
Scheme 59: Preparation of trichalcogenasumanenes 245 and 248.
Scheme 60: Design and synthesis of trichalcogenasumanene derivatives 252 and 178.
Scheme 61: Synthesis of spirosumanenes 264–269 and non-spiroheterasumanenes 258–263.
Scheme 62: Synthesis of sumanene-type hetero polycyclic compounds.
Scheme 63: Synthesis of triazasumanenes 288 and its sulfone congener 287.
Scheme 64: Synthesis of C3-symmetric chiral triaryltriazasumanenes via cross-coupling reaction.
Scheme 65: Synthesis of mononaphthosumanene 293 using Suzuki coupling as a key step.
Scheme 66: Synthesis of di- and trinaphthosumanene derivatives 302–304.
Scheme 67: Synthesis of hemifullerene skeletons by Hirao’s group.
Scheme 68: Design and construction of C70 fragment from a C60 sumanene fragment.
Beilstein J. Org. Chem. 2020, 16, 2141–2150, doi:10.3762/bjoc.16.182
Graphical Abstract
Figure 1: Examples of lipophilicity modulation for geminal dimethyl to cyclopropyl and oxetane modifications ...
Figure 2: Lipophilicity modulation examples involving fluorinated cyclopropane derivatives (measured experime...
Figure 3: Lipophilicity changes upon fluorination of isopropyl, cyclopropane and oxetane rings (Series A, C: ...
Figure 4: Lipophilicity modulations discussed in this contribution.
Figure 5: Distribution of the experimental lipophilicity values of series D, E and F (* denotes an estimated ...
Figure 6: Comparison of lipophilicities between the linear alkyl, isopropyl, cyclopropyl, and 3-oxetanyl subs...
Figure 7: Comparison of lipophilicities between isopropyl and cyclopropyl substituents grouped by exchange of...
Figure 8: Carbon extensions.
Figure 9: Experimental and theoretical (in blue) values (calculated at the MN15/aug-cc-pVTZ//MN15/cc-pVTZ lev...
Figure 10: Correlation of the DFT-calculated lipophilicities with the experimental values. A) fluorinated seri...
Figure 11: Experimental (in black) and theoretical (in blue) values (calculated at the MN15/aug-cc-pVTZ//MN15/...
Beilstein J. Org. Chem. 2020, 16, 1936–1946, doi:10.3762/bjoc.16.160
Graphical Abstract
Figure 1: Representative fluorinated nucleos(t)ides and acyclonucleotides.
Figure 2: Acyclonucleotides as nucleotide surrogates.
Figure 3: Olefination approaches and ring-opening of oxetane derivatives.
Scheme 1: Preparation of fluoroakylidene-oxetanes and their ring-opening reactions.
Scheme 2: Synthesis of benzyloxy-substituted fluoroethylidene-oxetane derivative 8.
Scheme 3: Effect of the medium on the selective formation of derivative 10.
Scheme 4: Mechanism for the formation of dihydrofuran 10.
Scheme 5: Mechanism for the formation of unsaturated lactones 14 and 15.
Scheme 6: Opening reaction of ethyl 2-(oxetanyl-3-idene)acetate (16).
Scheme 7: Functionalization of bromomethyllactone 15 and its analogues.
Scheme 8: Functionalization by substitution reaction of the bromide E-1d vs ring-opening reaction of the oxet...
Scheme 9: Preparation of tetrasubstituted fluoroalkenes.
Beilstein J. Org. Chem. 2020, 16, 1805–1819, doi:10.3762/bjoc.16.148
Graphical Abstract
Scheme 1: Oxazolidinone (1), five-membered cyclic carbonate (2) and some important compounds containing an ox...
Scheme 2: Proposed mechanisms by Keshava Murthy and Dhar [41] and De Meijere and co-workers [42].
Figure 1: Possible pathways for the formation of oxazolidinone intermediates 10 and 11. Optimized transition ...
Figure 2: Potential energy profile related to the formation of oxazolidinone intermediates 10 and 11 at the P...
Figure 3: IRC calculated for the formation of (a) 10 and (b) 11 at M06-2X/6-31+G(d,p) level. I-1, I-15, I-35, ...
Figure 4: Optimized geometries for the stationary points for the formation of 10 at PCM(DCM)/M06-2X/6-31+G(d,...
Scheme 3: Proposed mechanisms for the formation of oxazolidinone 9f.
Figure 5: Potential energy profiles for paths 1a (blue), 1b (red), 2 (green) and relative Gibbs free energies...
Figure 6: Optimized geometries for the stationary points of path 1b at PCM(DCM)/M06-2X/6-31+G(d,p)//M06-2X/6-...
Scheme 4: Proposed mechanism for the formation of five-membered cyclic carbonate 8f.
Figure 7: Potential energy profile and relative Gibbs free energies (kcal/mol) in DCM related to the formatio...
Figure 8: Optimized geometries for the stationary points of step 1 for the formation of 16 at PCM(DCM)/M06-2X...
Figure 9: Optimized geometries for the stationary points of step 2 for the formation of 17 at PCM(DCM)/M06-2X...
Figure 10: Optimized geometries for the stationary points of step 3 for the formation of PC8 at PCM(DCM)/M06-2...
Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123
Graphical Abstract
Figure 1: Bioactive phenanthridine and phenanthridinium derivatives.
Scheme 1: Synthesis of phenanthrenes by a photo-Pschorr reaction.
Scheme 2: Synthesis of phenanthrenes by a benzannulation reaction.
Scheme 3: Photocatalytic cyclization of α-bromochalcones for the synthesis of phenanthrenes.
Figure 2: Carbon-centered and nitrogen-centered radicals used for the synthesis of phenanthridines.
Scheme 4: General scheme describing the synthesis of phenanthridines from isocyanides via imidoyl radicals.
Scheme 5: Synthesis of substituted phenanthridines involving the intermediacy of electrophilic radicals.
Scheme 6: Photocatalyzed synthesis of 6-β-ketoalkyl phenanthridines.
Scheme 7: Synthesis of 6-substituted phenanthridines through the addition of trifluoromethyl (path a), phenyl...
Scheme 8: Synthesis of 6-(trifluoromethyl)-7,8-dihydrobenzo[k]phenanthridine.
Scheme 9: Phenanthridine syntheses by using photogenerated radicals formed through a C–H bond homolytic cleav...
Scheme 10: Trifluoroacetimidoyl chlorides as starting substrates for the synthesis of 6-(trifluoromethyl)phena...
Scheme 11: Synthesis of phenanthridines via aryl–aryl-bond formation.
Scheme 12: Oxidative conversion of N-biarylglycine esters to phenanthridine-6-carboxylates.
Scheme 13: Photocatalytic synthesis of benzo[f]quinolines from 2-heteroaryl-substituted anilines and heteroary...
Scheme 14: Synthesis of noravicine (14.2a) and nornitidine (14.2b) alkaloids.
Scheme 15: Gram-scale synthesis of the alkaloid trisphaeridine (15.3).
Scheme 16: Synthesis of phenanthridines starting from vinyl azides.
Scheme 17: Synthesis of pyrido[4,3,2-gh]phenanthridines 17.5a–d through the radical trifluoromethylthiolation ...
Scheme 18: The direct oxidative C–H amidation involving amidyl radicals for the synthesis of phenanthridones.
Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107
Graphical Abstract
Figure 1: Imine-N-oxyl radicals (IV) discussed in the present review and other classes of N-oxyl radicals (I–...
Figure 2: The products of decomposition of iminoxyl radicals generated from oximes by oxidation with Ag2O.
Scheme 1: Generation of oxime radicals and study of the kinetics of their decay by photolysis of the solution...
Scheme 2: Synthesis of di-tert-butyliminoxyl radical and its decomposition products.
Scheme 3: The proposed reaction pathway of the decomposition of di-tert-butyliminoxyl radical (experimentally...
Scheme 4: Monomolecular decomposition of the tert-butyl(triethylmethyl)oxime radical.
Scheme 5: The synthesis and stability of the most stable dialkyl oxime radicals – di-tert-butyliminoxyl and d...
Scheme 6: The formation of iminoxyl radicals from β-diketones under the action of NO2.
Scheme 7: Synthesis of the diacetyliminoxyl radical.
Scheme 8: Examples of long-living oxime radicals with electron-withdrawing groups and the conditions for thei...
Figure 3: The electronic structure iminoxyl radicals and their geometry compared to the corresponding oximes.
Figure 4: Bond dissociation enthalpies (kcal/mol) of oximes and N,N-disubstituted hydroxylamines calculated o...
Scheme 9: Examples demonstrating the low reactivity of the di-tert-butyliminoxyl radical towards the substrat...
Scheme 10: The reactions of di-tert-butyliminoxyl radical with unsaturated hydrocarbons involving hydrogen ato...
Scheme 11: Possible mechanisms of reaction of di-tert-butyliminoxyl radical with alkenes.
Scheme 12: Products of the reaction between di-tert-butyliminoxyl radical and phenol derivatives.
Scheme 13: The reaction of di-tert-butyliminoxyl radical with amines.
Scheme 14: Reaction of di-tert-butyliminoxyl radicals with organolithium reagents.
Scheme 15: Cross-dehydrogenative C–O coupling of 1,3-dicarbonyl compounds with oximes under the action of mang...
Scheme 16: Cross-dehydrogenative C–O coupling of 1,3-dicarbonyl compounds with oximes under the action of Cu(BF...
Scheme 17: Oxidative C–O coupling of benzylmalononitrile (47) with 3-(hydroxyimino)pentane-2,4-dione (19).
Scheme 18: The proposed mechanism of the oxidative coupling of benzylmalononitrile (47) with diacetyl oxime (19...
Scheme 19: Oxidative C–O coupling of pyrazolones with oximes under the action of Fe(ClO4)3.
Scheme 20: The reaction of diacetyliminoxyl radical with pyrazolones.
Scheme 21: Oxidative C–O coupling of oximes with acetonitrile, ketones, and esters.
Scheme 22: Intramolecular cyclizations of oxime radicals to form substituted isoxazolines or cyclic nitrones.
Scheme 23: TEMPO-mediated oxidative cyclization of oximes with C–H bond cleavage.
Scheme 24: Proposed reaction mechanism of oxidative cyclization of oximes with C–H bond cleavage.
Scheme 25: Selectfluor/Bu4NI-mediated C–H oxidative cyclization of oximes.
Scheme 26: Oxidative cyclization of N-benzyl amidoximes to 1,2,4-oxadiazoles.
Scheme 27: The formation of quinazolinone 73a from 5-phenyl-4,5-dihydro-1,2,4-oxadiazole 74 under air.
Scheme 28: DDQ-mediated oxidative cyclization of thiohydroximic acids.
Scheme 29: Plausible mechanism of the oxidative cyclization of thiohydroximic acids.
Scheme 30: Silver-mediated oxidative cyclization of α-halogenated ketoximes and 1,3-dicarbonyl compounds.
Scheme 31: Possible pathway of one-pot oxidative cyclization of α-halogenated ketoximes and 1,3-dicarbonyl com...
Scheme 32: T(p-F)PPT-catalyzed oxidative cyclization of oximes with the formation of 1,2,4-oxadiazolines.
Scheme 33: Intramolecular cyclization of iminoxyl radicals involving multiple C=C and N=N bonds.
Scheme 34: Oxidative cyclization of β,γ- and γ,δ-unsaturated oximes employing the DEAD or TEMPO/DEAD system wi...
Scheme 35: Cobalt-catalyzed aerobic oxidative cyclization of β,γ-unsaturated oximes.
Scheme 36: Manganese-catalyzed aerobic oxidative cyclization of β,γ-unsaturated oximes.
Scheme 37: Visible light photocatalytic oxidative cyclization of β,γ-unsaturated oximes.
Scheme 38: TBAI/TBHP-mediated radical cascade cyclization of the β,γ-unsaturated oximes.
Scheme 39: TBAI/TBHP-mediated radical cascade cyclization of vinyl isocyanides with β,γ-unsaturated oximes.
Scheme 40: tert-Butylnitrite-mediated oxidative cyclization of unsaturated oximes with the introduction of an ...
Scheme 41: Transformation of unsaturated oxime to oxyiminomethylisoxazoline via the confirmed dimeric nitroso ...
Scheme 42: tert-Butylnitrite-mediated oxidative cyclization of unsaturated oximes with the introduction of a n...
Scheme 43: Synthesis of cyano-substituted oxazolines from unsaturated oximes using the TBN/[RuCl2(p-cymene)]2 ...
Scheme 44: Synthesis of trifluoromethylthiolated isoxazolines from unsaturated oximes.
Scheme 45: Copper-сatalyzed oxidative cyclization of β,γ-unsaturated oximes with the introduction of an azido ...
Scheme 46: TBHP-mediated oxidative cascade cyclization of β,γ-unsaturated oximes and unsaturated N-arylamides.
Scheme 47: Copper-сatalyzed oxidative cyclization of unsaturated oximes with the introduction of an amino grou...
Scheme 48: TEMPO-mediated oxidative cyclization of unsaturated oximes followed by elimination.
Scheme 49: Oxidative cyclization of β,γ-unsaturated oximes with the introduction of a trifluoromethyl group.
Scheme 50: Oxidative cyclization of unsaturated oximes with the introduction of a nitrile group.
Scheme 51: Oxidative cyclization of β,γ-unsaturated oximes to isoxazolines with the introduction of a nitrile ...
Scheme 52: Oxidative cyclization of β,γ-unsaturated oximes to isoxazolines with the introduction of a sulfonyl...
Scheme 53: Oxidative cyclization of β,γ- and γ,δ-unsaturated oximes to isoxazolines with the introduction of a...
Scheme 54: Oxidative cyclization of β,γ-unsaturated oximes to isoxazolines with the introduction of a thiocyan...
Scheme 55: PhI(OAc)2-mediated oxidative cyclization of oximes with C–S and C–Se bond formation.
Scheme 56: PhI(OAc)2-mediated oxidative cyclization of unsaturated oximes accompanied by alkoxylation.
Scheme 57: PhI(OAc)2-mediated cyclization of unsaturated oximes to methylisoxazolines.
Scheme 58: Oxidative cyclization-alkynylation of unsaturated oximes.
Scheme 59: TEMPO-mediated oxidative cyclization of C-glycoside ketoximes to C-glycosylmethylisoxazoles.
Scheme 60: Silver-сatalyzed oxidative cyclization of β,γ-unsaturated oximes with formation of fluoroalkyl isox...
Scheme 61: Oxidative cyclization of β,γ-unsaturated oximes with the formation of haloalkyl isoxazolines.
Scheme 62: Cyclization of β,γ-unsaturated oximes into haloalkyl isoxazolines under the action of the halogenat...
Scheme 63: Synthesis of haloalkyl isoxazoles and cyclic nitrones via oxidative cyclization and 1,2-halogen shi...
Scheme 64: Electrochemical oxidative cyclization of diaryl oximes.
Scheme 65: Copper-сatalyzed cyclization and dioxygenation oximes containing a triple C≡C bond.
Scheme 66: Photoredox-catalyzed sulfonylation of β,γ-unsaturated oximes by sulfonyl hydrazides.
Scheme 67: Oxidative cyclization of β,γ-unsaturated oximes with introduction of sulfonate group.
Scheme 68: Ultrasound-promoted oxidative cyclization of β,γ-unsaturated oximes.