Search for "C–O bond" in Full Text gives 152 result(s) in Beilstein Journal of Organic Chemistry.
Beilstein J. Org. Chem. 2020, 16, 917–955, doi:10.3762/bjoc.16.83
Graphical Abstract
Figure 1: Chemical structures of the porphyrinoids and their absorption spectra: in bold are highlighted the ...
Figure 2: Photophysical and photochemical processes (Por = porphyrin). Adapted from [12,18].
Figure 3: Main dual photocatalysts and their oxidative/reductive excited state potentials, including porphyri...
Scheme 1: Photoredox alkylation of aldehydes with diazo acetates using porphyrins and a Ru complex. aUsing a ...
Scheme 2: Proposed mechanism for the alkylation of aldehydes with diazo acetates in the presence of TPP.
Scheme 3: Arylation of heteroarenes with aryldiazonium salts using TPFPP as photocatalyst, and corresponding ...
Scheme 4: A) Scope with different aryldiazonium salts and enol acetates. B) Photocatalytic cycles and compari...
Scheme 5: Photoarylation of isopropenyl acetate A) Comparison between batch and continuous-flow approaches an...
Scheme 6: Dehalogenation induced by red light using thiaporphyrin (STPP).
Scheme 7: Applications of NiTPP as both photoreductant and photooxidant.
Scheme 8: Proposed mechanism for obtaining tetrahydroquinolines by reductive quenching.
Scheme 9: Selenylation and thiolation of anilines.
Scheme 10: NiTPP as photoredox catalyst in oxidative and reductive quenching, in comparison with other photoca...
Scheme 11: C–O bond cleavage of 1-phenylethanol using a cobalt porphyrin (CoTMPP) under visible light.
Scheme 12: Hydration of terminal alkynes by RhIII(TSPP) under visible light irradiation.
Scheme 13: Regioselective photocatalytic hydro-defluorination of perfluoroarenes by RhIII(TSPP).
Scheme 14: Formation of 2-methyl-2,3-dihydrobenzofuran by intramolecular hydro-functionalization of allylpheno...
Scheme 15: Photocatalytic oxidative hydroxylation of arylboronic acids using UNLPF-12 as heterogeneous photoca...
Scheme 16: Photocatalytic oxidative hydroxylation of arylboronic acids using MOF-525 as heterogeneous photocat...
Scheme 17: Preparation of the heterogeneous photocatalyst CNH.
Scheme 18: Photoinduced sulfonation of alkenes with sulfinic acid using CNH as photocatalyst.
Scheme 19: Sulfonic acid scope of the sulfonation reactions.
Scheme 20: Regioselective sulfonation reaction of arimistane.
Scheme 21: Synthesis of quinazolin-4-(3H)-ones.
Scheme 22: Selective photooxidation of aromatic benzyl alcohols to benzaldehydes using Pt/PCN-224(Zn).
Scheme 23: Photooxidation of benzaldehydes to benzoic acids using Pt or Pd porphyrins.
Scheme 24: Photocatalytic reduction of various nitroaromatics using a Ni-MOF.
Scheme 25: Photoinduced cycloadditions of CO2 with epoxides by MOF1.
Figure 4: Electronic configurations of the species of oxygen. Adapted from [66].
Scheme 26: TPP-photocatalyzed generation of 1O2 and its application in organic synthesis. Adapted from [67-69].
Scheme 27: Pericyclic reactions involving singlet oxygen and their mechanisms. Adapted from [67].
Scheme 28: First scaled up ascaridole preparation from α-terpinene.
Scheme 29: Antimalarial drug synthesis using an endoperoxidation approach.
Scheme 30: Photooxygenation of colchicine.
Scheme 31: Synthesis of (−)-pinocarvone from abundant (+)-α-pinene.
Scheme 32: Seeberger’s semi-synthesis of artemisinin.
Scheme 33: Synthesis of artemisinin using TPP and supercritical CO2.
Scheme 34: Synthesis of artemisinin using chlorophyll a.
Scheme 35: Quercitol stereoisomer preparation.
Scheme 36: Photocatalyzed preparation of naphthoquinones.
Scheme 37: Continuous endoperoxidation of conjugated dienes and subsequent rearrangements leading to oxidized ...
Scheme 38: The Opatz group total synthesis of (–)-oxycodone.
Scheme 39: Biomimetic syntheses of rhodonoids A, B, E, and F.
Scheme 40: α-Photooxygenation of chiral aldehydes.
Scheme 41: Asymmetric photooxidation of indanone β-keto esters by singlet oxygen using PTC as a chiral inducer...
Scheme 42: Asymmetric photooxidation of both β-keto esters and β-keto amides by singlet oxygen using PTC-2 as ...
Scheme 43: Bifunctional photo-organocatalyst used for the asymmetric oxidation of β-keto esters and β-keto ami...
Scheme 44: Mechanism of singlet oxygen oxidation of sulfides to sulfoxides.
Scheme 45: Controlled oxidation of sulfides to sulfoxides using protonated porphyrins as photocatalysts. aIsol...
Scheme 46: Photochemical oxidation of sulfides to sulfoxides using PdTPFPP as photocatalyst.
Scheme 47: Controlled oxidation of sulfides to sulfoxides using SnPor@PAF as a photosensitizer.
Scheme 48: Syntheses of 2D-PdPor-COF and 3D-Pd-COF.
Scheme 49: Photocatalytic oxidation of A) thioanisole to methyl phenyl sulfoxide and B) various aryl sulfides,...
Scheme 50: General mechanism for oxidation of amines to imines.
Scheme 51: Oxidation of secondary amines to imines.
Scheme 52: Oxidation of secondary amines using Pd-TPFPP as photocatalyst.
Scheme 53: Oxidative amine coupling using UNLPF-12 as heterogeneous photocatalyst.
Scheme 54: Synthesis of Por-COF-1 and Por-COF-2.
Scheme 55: Photocatalytic oxidation of amines to imines by Por-COF-2.
Scheme 56: Photocyanation of primary amines.
Scheme 57: Synthesis of ᴅ,ʟ-tert-leucine hydrochloride.
Scheme 58: Photocyanation of catharanthine and 16-O-acetylvindoline using TPP.
Scheme 59: Photochemical α-functionalization of N-aryltetrahydroisoquinolines using Pd-TPFPP as photocatalyst.
Scheme 60: Ugi-type reaction with 1,2,3,4-tetrahydroisoquinoline using molecular oxygen and TPP.
Scheme 61: Ugi-type reaction with dibenzylamines using molecular oxygen and TPP.
Scheme 62: Mannich-type reaction of tertiary amines using PdTPFPP as photocatalyst.
Scheme 63: Oxidative Mannich reaction using UNLPF-12 as heterogeneous photocatalyst.
Scheme 64: Transformation of amines to α-cyanoepoxides and the proposed mechanism.
Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77
Graphical Abstract
Scheme 1: Copper complexes with amidophenolate type benzoxazole ligands for alcohol oxidations.
Scheme 2: Copper-catalyzed aerobic oxidation of alcohols and representative substrate scope.
Scheme 3: Introduction of H-bonding network in the ligand coordination sphere.
Scheme 4: Well-defined isatin copper complexes.
Scheme 5: Catalyst control in the biomimetic phenol ortho-oxidation.
Scheme 6: Structural diversity accessible by direct functionalization.
Scheme 7: Copper-catalyzed trifluoromethylation of heteroaromatics with redox-active iminosemiquinone ligands....
Scheme 8: Reversal of helical chirality upon redox stimuli and enantioselective Michael addition with a redox...
Scheme 9: Interaction of guanidine-copper catalyst with oxygen and representative coupling products. a4 mol %...
Scheme 10: Access to 1,2-oxy-aminoarenes by copper-catalyzed phenol–amine coupling.
Scheme 11: Copper-catalyzed aziridination through molecular spin catalysis with redox-active iminosemiquinone ...
Scheme 12: Nitrogen-group and carbon-group transfer in copper-catalyzed aziridination and cyclopropanation thr...
Beilstein J. Org. Chem. 2020, 16, 674–680, doi:10.3762/bjoc.16.65
Graphical Abstract
Figure 1: Examples of liquid crystal candidates with negative values for dielectric anisotropy (Δε) [6-10].
Figure 2: Synthetic candidate LC targets 8–11.
Scheme 1: Synthesis of 8. Reagents and conditions: a) TMSCF3, NaI, THF, reflux, 55% [13,14].
Scheme 2: Synthesis of 9. Reagents and conditions: a) NBS, HF·Py, DCM; b) t-BuOK, DCM, 42% in two steps [15]; c) ...
Scheme 3: Synthesis of compound 10. Reagents and conditions: a) NaBH4, MeOH, rt, 45%; b) C4H9OCH=CH2, Pd(TFA)2...
Scheme 4: Synthesis of compounds 11. Reagents and conditions: a) PPh3CH3Br, t-BuOK, diethyl ether, 0 °C to rt...
Figure 3: Theory study exploring the relative energies for different conformers of 11a.
Beilstein J. Org. Chem. 2020, 16, 544–550, doi:10.3762/bjoc.16.51
Graphical Abstract
Scheme 1: Projected synthetic routes for 3,6,13,16-tetrasubstituted tetrabenzo[a,d,j,m]coronenes.
Scheme 2: Reported syntheses of 2,7,12,17-tetrasubstituted tetrabenzo[a,d,j,m]coronenes.
Scheme 3: C–H tetraarylation of anthraquinone (1).
Scheme 4: C–H diarylation of 1,4-diarylanthraquinones 5.
Figure 1: Normalized UV–vis absorption spectra of 7aa, 7bb, and 7ba.
Figure 2: Effects of the concentration and the temperature on the 1H NMR spectra of 7aa.
Beilstein J. Org. Chem. 2020, 16, 88–105, doi:10.3762/bjoc.16.11
Graphical Abstract
Scheme 1: Arbusov, phospha-Fries, and phospha-Brook rearrangements.
Scheme 2: Cyclization of 1a and 1b under acidic conditions.
Scheme 3: The synthesis of P-stereogenic β-hydroxyalkylphosphine sulfides.
Scheme 4: Cyclization of 8 and 19 in the presence of H3PO4.
Scheme 5: Cyclization of (SP)-19 in the presence of H3PO4.
Figure 1: 1H NMR spectra of compounds 12 and 29.
Figure 2: 13C NMR spectra of compounds 12 and 29.
Scheme 6: Synthesis of the alkenylphosphine sulfides used in study.
Scheme 7: The reaction of mesylate compounds with Lewis-acidic AlCl3.
Scheme 8: The reaction of alkenylphosphine sulfides with AlCl3.
Scheme 9: Rearrangement of 20 in the presence of Brønsted acid. The calculated energies next to the arrows ar...
Scheme 10: Rearrangement of 20 in the presence of Lewis acid. The calculated energies next to the arrows are r...
Scheme 11: The synthesis of chiral substrates for rearrangement reactions.
Scheme 12: The reaction of (SP)-60 and (SP)-65 with AlCl3.
Scheme 13: Reaction of chiral β-hydroxyalkylphosphine sulfides with Brønsted acid.
Scheme 14: Attempted cyclization of enantiomerically enriched 53 and 46.
Beilstein J. Org. Chem. 2019, 15, 2948–2957, doi:10.3762/bjoc.15.290
Graphical Abstract
Scheme 1: Ireland–Claisen rearrangement of allyl esters 1a–c.
Scheme 2: Ireland–Claisen rearrangement of 1c mediated by tertiary amines.
Figure 1: Organocatalysts used in this study. Conditions: typical procedure: 1. Et3N (4.9 equiv), DCM, −60 °C...
Scheme 3: Solvent-free Ireland–Claisen rearrangement of cinnamyl esters.
Figure 2: ωB97X-D/6-31G* calculated uncatalyzed Ireland–Claisen rearrangement of 1c. Charges on allylic oxyge...
Figure 3: ωB97X-D/6-31G* calculated Schreiner thiourea (12)-catalyzed Ireland–Claisen rearrangement of 1c. Ch...
Figure 4: ωB97X-D/6-31G* calculated Ph-thiourea (top) and squaramide-catalyzed (bottom) Ireland–Claisen rearr...
Figure 5: a) Rate of product formation; b) reaction profile without catalyst determined by 1H NMR.
Beilstein J. Org. Chem. 2019, 15, 2419–2427, doi:10.3762/bjoc.15.234
Graphical Abstract
Figure 1: Oxazolone pseudodipeptide 1 and tetrapeptide 2a.
Scheme 1: Synthesis of linear azido ester dipeptide 5 and tetrapeptide 7.
Scheme 2: Synthesis of oxazolone pseudopeptides 1, 2a and 2b.
Figure 2: Characteristic NOEs of 2a.
Figure 3: DMSO titration study of 2a.
Figure 4: 1H NMR temperature study of 2a.
Figure 5: Optimized helical conformations of (A) 2a, (B) 2b and (C) 9.
Figure 6: Ion transport activity (A) for 1, (B) for 2a, across EYPC-LUVs HPTS.
Figure 7: Cation (A) and anion (B) transport activity of 2a.
Figure 8:
Comparison of the ion transport activity of 2a and 2b at 20 µM across EYPC-LUVslucigenin (A). Conce...
Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218
Graphical Abstract
Scheme 1: The main three strategies of fluorination: nucleophilic, electrophilic and radical fluorination.
Scheme 2: Doyle’s Pd-catalyzed fluorination of allylic chlorides.
Scheme 3: Allylic fluorination of 2- and 3-substituted propenyl esters.
Scheme 4: Regioselective allylic fluorination of cinnamyl phosphorothioate esters.
Scheme 5: Palladium-catalyzed aliphatic C–H fluorination reported by Doyle.
Scheme 6: Pd-catalyzed enantioselective fluorination of α-ketoesters followed by stereoselective reduction to...
Scheme 7: Pd-catalyzed C(sp3)–H fluorination of oxindoles.
Scheme 8: C–H fluorination of 8-methylquinoline derivatives with F− reagents.
Scheme 9: Fluorination of α-cyano acetates reported by van Leeuwen.
Scheme 10: The catalytic enantioselective electrophilic C–H fluorination of α-chloro-β-keto phosphonates.
Scheme 11: Fluorination of unactivated C(sp3)–H bonds directed by the bidentate PIP auxiliary.
Scheme 12: Fluorination of C(sp3)–H bonds at the β-position of carboxylic acids.
Scheme 13: Enantioselective benzylic C–H fluorination with a chiral transient directing group.
Scheme 14: Microwave-heated Pd-catalyzed fluorination of aryl alcohols.
Scheme 15: Fluorination of aryl potassium trifluoroborates.
Scheme 16: C(sp2)–F bond formation using precatalyst [L·Pd]2(cod).
Scheme 17: Pd-catalyzed fluorination of (hetero)aryl triflates and bromides.
Scheme 18: The Pd-catalyzed C–H fluorination of arenes with Selectfluor/NFSI.
Scheme 19: Pd(II)-catalyzed ortho-monofluorination protocol for benzoic acids.
Scheme 20: Pd-catalyzed C(sp2)–H bond fluorination of 2-arylbenzothiazoles.
Scheme 21: Nitrate-promoted fluorination of aromatic and olefinic C(sp2)–H bonds and proposed mechanism.
Scheme 22: Fluorination of oxalyl amide-protected benzylamine derivatives.
Scheme 23: C–H fluorination of benzaldehydes with orthanilic acids as transient directing group.
Scheme 24: Pd(II)-catalyzed aryl C–H fluorination with various directing groups.
Scheme 25: Cu-catalyzed aliphatic, allylic, and benzylic fluorination.
Scheme 26: Cu-catalyzed SN2 fluorination of primary and secondary alkyl bromides.
Scheme 27: Copper-catalyzed fluorination of alkyl triflates.
Scheme 28: Cu-catalyzed fluorination of allylic bromides and chlorides.
Scheme 29: Synthetic strategy for the fluorination of active methylene compounds.
Scheme 30: Fluorination of β-ketoesters using a tartrate-derived bidentate bisoxazoline-Cu(II) complex.
Scheme 31: Highly enantioselective fluorination of β-ketoesters and N-Boc-oxindoles.
Scheme 32: Amide group-assisted site-selective fluorination of α-bromocarbonyl compounds.
Scheme 33: Cu-mediated aryl fluorination reported by Sanford [77].
Scheme 34: Mono- or difluorination reactions of benzoic acid derivatives.
Scheme 35: Cu-catalyzed fluorination of diaryliodonium salts with KF.
Scheme 36: Copper(I)-catalyzed cross-coupling of 2-pyridylaryl bromides.
Scheme 37: AgNO3-catalyzed decarboxylative fluorination of aliphatic carboxylic acids.
Scheme 38: The Mn-catalyzed aliphatic and benzylic C–H fluorination.
Scheme 39: Iron(II)-promoted C–H fluorination of benzylic substrates.
Scheme 40: Ag-catalyzed fluorodecarboxylation of carboxylic acids.
Scheme 41: Vanadium-catalyzed C(sp3)–H fluorination.
Scheme 42: AgNO3-catalyzed radical deboronofluorination of alkylboronates and boronic acids.
Scheme 43: Selective heterobenzylic C–H fluorination with Selectfluor reported by Van Humbeck.
Scheme 44: Fe(II)-catalyzed site-selective fluorination guided by an alkoxyl radical.
Scheme 45: Fluorination of allylic trichloroacetimidates reported by Nguyen et al.
Scheme 46: Iridium-catalyzed fluorination of allylic carbonates with TBAF(t-BuOH)4.
Scheme 47: Iridium-catalyzed asymmetric fluorination of allylic trichloroacetimidates.
Scheme 48: Cobalt-catalyzed α-fluorination of β-ketoesters.
Scheme 49: Nickel-catalyzed α-fluorination of various α-chloro-β-ketoesters.
Scheme 50: Ni(II)-catalyzed enantioselective fluorination of oxindoles and β-ketoesters.
Scheme 51: Scandium(III)-catalyzed asymmetric C–H fluorination of unprotected 3-substituted oxindoles.
Scheme 52: Iron-catalyzed directed C–H fluorination.
Scheme 53: Electrophilic silver-catalyzed Ar–F bond-forming reaction from arylstannanes.
Figure 1: Nucleophilic, electrophilic and radical CF3 sources.
Scheme 54: Cu(I)-catalyzed allylic trifluoromethylation of unactivated terminal olefins.
Scheme 55: Direct copper-catalyzed trifluoromethylation of allylsilanes.
Scheme 56: Cupper-catalyzed enantioselective trifluoromethylation of five and six-membered ring β-ketoesters.
Scheme 57: Cu-catalyzed highly stereoselective trifluoromethylation of secondary propargyl sulfonates.
Scheme 58: Remote C(sp3)–H trifluoromethylation of carboxamides and sulfonamides.
Scheme 59: Trifluoromethylation of allylsilanes with photoredox catalysis.
Scheme 60: Ag-catalyzed decarboxylative trifluoromethylation of aliphatic carboxylic acids in aqueous CH3CN.
Scheme 61: Decarboxylative trifluoromethylation of aliphatic carboxylic acids via combined photoredox and copp...
Scheme 62: Palladium-catalyzed Ar–CF3 bond-forming reaction.
Scheme 63: Palladium-catalyzed trifluoromethylation of arenes with diverse heterocyclic directing groups.
Scheme 64: Pd-catalyzed trifluoromethylation of indoles as reported by Liu.
Scheme 65: Pd-catalyzed trifluoromethylation of vinyl triflates and vinyl nonaflates.
Scheme 66: Pd(II)-catalyzed ortho-trifluoromethylation of aromatic C–H bonds.
Scheme 67: Visible-light-induced Pd(OAc)2-catalyzed ortho-trifluoromethylation of acetanilides with CF3SO2Na.
Scheme 68: CuI-catalyzed trifluoromethylation of aryl- and alkenylboronic acids.
Scheme 69: Cu-catalyzed trifluoromethylation of aryl- and vinylboronic acids.
Scheme 70: Copper-catalyzed trifluoromethylation of α,β-unsaturated carboxylic acids.
Scheme 71: Formation of C(sp2)–CF3 bond catalyzed by copper(I) complex.
Scheme 72: Loh’s Cu(I)-catalyzed trifluoromethylation of enamides and electron-deficient alkenes.
Scheme 73: Copper and iron-catalyzed decarboxylative tri- and difluoromethylation.
Scheme 74: Cu-catalyzed trifluoromethylation of hydrazones developed by Bouyssi.
Scheme 75: Cu(I)-catalyzed trifluoromethylation of terminal alkenes.
Scheme 76: Cu/Ag-catalyzed decarboxylative trifluoromethylation of cinnamic acids.
Scheme 77: Copper-catalyzed direct alkenyl C–H trifluoromethylation.
Scheme 78: Copper(I/II)-catalyzed direct trifluoromethylation of styrene derivatives.
Scheme 79: Regioselective trifluoromethylation of pivalamido arenes and heteroarenes.
Scheme 80: Synthesis of trifluoromethylquinones in the presence of copper(I).
Scheme 81: Oxidative trifluoromethylation of imidazoheterocycles in ionic liquid/water.
Scheme 82: A mild and fast continuous-flow trifluoromethylation of coumarins using a CuI/CF3SO2Na/TBHP system.
Scheme 83: Copper-catalyzed oxidative trifluoromethylation of various 8-aminoquinolines.
Scheme 84: PA-directed copper-catalyzed trifluoromethylation of anilines.
Scheme 85: Trifluoromethylation of potassium vinyltrifluoroborates catalyzed by Fe(II).
Scheme 86: Alkenyl trifluoromethylation catalyzed by Ru(phen)3Cl2 as photocatalyst.
Scheme 87: Ru-catalyzed trifluoromethylation of alkenes by Akita’s group.
Scheme 88: Ir-catalyzed Cvinyl–CF3 bond formation of α,β-unsaturated carboxylic acids.
Scheme 89: Ag(I)-catalyzed denitrative trifluoromethylation of β-nitrostyrenes.
Scheme 90: Photocatalyzed direct trifluoromethylation of aryl and heteroaryl C–H bonds.
Scheme 91: Rhenium (MTO)-catalyzed direct trifluoromethylation of aromatic substrates.
Scheme 92: Trifluoromethylation of unprotected anilines under [Ir(ppy)3] catalyst.
Scheme 93: Oxidative trifluoromethylation of imidazopyridines and imidazoheterocycles.
Scheme 94: Ruthenium-catalyzed trifluoromethylation of (hetero)arenes with trifluoroacetic anhydride.
Scheme 95: Phosphovanadomolybdic acid-catalyzed direct C–H trifluoromethylation.
Scheme 96: Picolinamide-assisted ortho-trifluoromethylation of arylamines.
Scheme 97: A nickel-catalyzed C–H trifluoromethylation of free anilines.
Scheme 98: Cu-mediated trifluoromethylation of terminal alkynes reported by Qing.
Scheme 99: Huang’s C(sp)–H trifluoromethylation using Togni’s reagent.
Scheme 100: Cu-catalyzed methods for trifluoromethylation with Umemoto’s reagent.
Scheme 101: The synthesis of alkynyl-CF3 compounds in the presence of fac-[Ir(ppy)3] under visible-light irradi...
Scheme 102: Pd-catalyzed Heck reaction reported by Reutrakul.
Scheme 103: Difluoromethylation of enamides and ene-carbamates.
Scheme 104: Difluoromethylation of α,β-unsaturated carboxylic acids.
Scheme 105: Copper-catalyzed direct C(sp2)–H difluoroacetylation reported by Pannecoucke and co-workers.
Scheme 106: Difluoroalkylation of aldehyde-derived hydrazones with functionalized difluoromethyl bromides.
Scheme 107: Photoredox-catalyzed C–H difluoroalkylation of aldehyde-derived hydrazones.
Scheme 108: Synergistic ruthenium(II)-catalyzed C–H difluoromethylation reported by Ackermann.
Scheme 109: Visible-light photocatalytic decarboxylation of α,β-unsaturated carboxylic acids.
Scheme 110: Synthesis of difluorinated ketones via S-alkyl dithiocarbamates obtained from acyl chlorides and po...
Scheme 111: Synthesis of aryl and heteroaryl difluoromethylated phosphonates.
Scheme 112: Difluoroalkylation of secondary propargyl sulfonates using Cu as the catalyst.
Scheme 113: Ru(II)-mediated para-selective difluoromethylation of anilides and their derivatives.
Scheme 114: Bulky diamine ligand promoted cross-coupling of difluoroalkyl bromides.
Scheme 115: Copper-catalyzed C3–H difluoroacetylation of quinoxalinones.
Scheme 116: Copper(I) chloride-catalyzed trifluoromethylthiolation of enamines, indoles and β-ketoesters.
Scheme 117: Copper-boxmi-catalyzed asymmetric trifluoromethylthiolation of β-ketoesters.
Scheme 118: Direct Cu-catalyzed trifluoromethylthiolation of boronic acids and alkynes.
Scheme 119: Cu-catalyzed synthesis of α-trifluoromethylthio-substituted ketones.
Scheme 120: Trifluoromethylthiolation reactions promoted by diazotriflone and copper.
Scheme 121: Halide activation of N-(trifluoromethylthio)phthalimide.
Scheme 122: The visible light-promoted trifluoromethylthiolation reported by Glorius.
Scheme 123: Synthesis of α-trifluoromethylthioesters via Goossen’s approach.
Scheme 124: Photoinduced trifluoromethylthiolation of diazonium salts.
Scheme 125: Ag-mediated trifluoromethoxylation of aryl stannanes and arylboronic acids.
Scheme 126: Catalytic (hetero)aryl C–H trifluoromethoxylation under visible light.
Scheme 127: Photoinduced C–H-bond trifluromethoxylation of (hetero)arenes.
Beilstein J. Org. Chem. 2019, 15, 1864–1871, doi:10.3762/bjoc.15.182
Graphical Abstract
Scheme 1: Comparison of our work with previous studies.
Scheme 2: Scope of pyridinium salts and benzylamine substrates. Reaction conditions: 1 (1 mmol), 2 (1 mmol), ...
Scheme 3: Scope of pyridinium salts and benzyl alcohol substrates. Reaction conditions: 1 (1 mmol), 4 (1 mmol...
Scheme 4: Scope of pyridinium salts, primary and secondary amine substrates. Reaction conditions: 1 (1 mmol), ...
Scheme 5: Control experiments for the oxidative cleavage of C–C bonds.
Scheme 6: Plausible reaction mechanism for the synthesis of N-alkylated benzamides 3.
Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165
Graphical Abstract
Figure 1: Various drugs having IP nucleus.
Figure 2: Participation percentage of various TMs for the syntheses of IPs.
Scheme 1: CuI–NaHSO4·SiO2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 2: Experimental examination of reaction conditions.
Scheme 3: One-pot tandem reaction for the synthesis of 2-haloimidazopyridines.
Scheme 4: Mechanistic scheme for the synthesis of 2-haloimidazopyridine.
Scheme 5: Copper-MOF-catalyzed three-component reaction (3-CR) for imidazo[1,2-a]pyridines.
Scheme 6: Mechanism for copper-MOF-driven synthesis.
Scheme 7: Heterogeneous synthesis via titania-supported CuCl2.
Scheme 8: Mechanism involving oxidative C–H functionalization.
Scheme 9: Heterogeneous synthesis of IPs.
Scheme 10: One-pot regiospecific synthesis of imidazo[1,2-a]pyridines.
Scheme 11: Vinyl azide as an unprecedented substrate for imidazo[1,2-a]pyridines.
Scheme 12: Radical pathway.
Scheme 13: Cu(I)-catalyzed transannulation approach for imidazo[1,5-a]pyridines.
Scheme 14: Plausible radical pathway for the synthesis of imidazo[1,5-a]pyridines.
Scheme 15: A solvent-free domino reaction for imidazo[1,2-a]pyridines.
Scheme 16: Cu-NPs-mediated synthesis of imidazo[1,2-a]pyridines.
Scheme 17: CuI-catalyzed synthesis of isoxazolylimidazo[1,2-a]pyridines.
Scheme 18: Functionalization of 4-bromo derivative via Sonogashira coupling reaction.
Scheme 19: A plausible reaction pathway.
Scheme 20: Cu(I)-catalyzed intramolecular oxidative C–H amidation reaction.
Scheme 21: One-pot synthetic reaction for imidazo[1,2-a]pyridine.
Scheme 22: Plausible reaction mechanism.
Scheme 23: Cu(OAc)2-promoted synthesis of imidazo[1,2-a]pyridines.
Scheme 24: Mechanism for aminomethylation/cycloisomerization of propiolates with imines.
Scheme 25: Three-component synthesis of imidazo[1,2-a]pyridines.
Figure 3: Scope of pyridin-2(1H)-ones and acetophenones.
Scheme 26: CuO NPS-promoted A3 coupling reaction.
Scheme 27: Cu(II)-catalyzed C–N bond formation reaction.
Scheme 28: Mechanism involving Chan–Lam/Ullmann coupling.
Scheme 29: Synthesis of formyl-substituted imidazo[1,2-a]pyridines.
Scheme 30: A tandem sp3 C–H amination reaction.
Scheme 31: Probable mechanistic approach.
Scheme 32: Dual catalytic system for imidazo[1,2-a]pyridines.
Scheme 33: Tentative mechanism.
Scheme 34: CuO/CuAl2O4/ᴅ-glucose-promoted 3-CCR.
Scheme 35: A tandem CuOx/OMS-2-based synthetic strategy.
Figure 4: Biomimetic catalytic oxidation in the presence of electron-transfer mediators (ETMs).
Scheme 36: Control experiment.
Scheme 37: Copper-catalyzed C(sp3)–H aminatin reaction.
Scheme 38: Reaction of secondary amines.
Scheme 39: Probable mechanistic pathway.
Scheme 40: Coupling reaction of α-azidoketones.
Scheme 41: Probable pathway.
Scheme 42: Probable mechanism with free energy calculations.
Scheme 43: MCR for cyanated IP synthesis.
Scheme 44: Substrate scope for the reaction.
Scheme 45: Reaction mechanism.
Scheme 46: Probable mechanistic pathway for Cu/ZnAl2O4-catalyzed reaction.
Scheme 47: Copper-catalyzed double oxidative C–H amination reaction.
Scheme 48: Application towards different coupling reactions.
Scheme 49: Reaction mechanism.
Scheme 50: Condensation–cyclization approach for the synthesis of 1,3-diarylated imidazo[1,5-a]pyridines.
Scheme 51: Optimized reaction conditions.
Scheme 52: One-pot 2-CR.
Scheme 53: One-pot 3-CR without the isolation of chalcone.
Scheme 54: Copper–Pybox-catalyzed cyclization reaction.
Scheme 55: Mechanistic pathway catalyzed by Cu–Pybox complex.
Scheme 56: Cu(II)-promoted C(sp3)-H amination reaction.
Scheme 57: Wider substrate applicability for the reaction.
Scheme 58: Plausible reaction mechanism.
Scheme 59: CuI assisted C–N cross-coupling reaction.
Scheme 60: Probable reaction mechanism involving sp3 C–H amination.
Scheme 61: One-pot MCR-catalyzed by CoFe2O4/CNT-Cu.
Scheme 62: Mechanistic pathway.
Scheme 63: Synthetic scheme for 3-nitroimidazo[1,2-a]pyridines.
Scheme 64: Plausible mechanism for CuBr-catalyzed reaction.
Scheme 65: Regioselective synthesis of halo-substituted imidazo[1,2-a]pyridines.
Scheme 66: Synthesis of 2-phenylimidazo[1,2-a]pyridines.
Scheme 67: Synthesis of diarylated compounds.
Scheme 68: CuBr2-mediated one-pot two-component oxidative coupling reaction.
Scheme 69: Decarboxylative cyclization route to synthesize 1,3-diarylimidazo[1,5-a]pyridines.
Scheme 70: Mechanistic pathway.
Scheme 71: C–H functionalization reaction of enamines to produce diversified heterocycles.
Scheme 72: A plausible mechanism.
Scheme 73: CuI-promoted aerobic oxidative cyclization reaction of ketoxime acetates and pyridines.
Scheme 74: CuI-catalyzed pathway for the formation of imidazo[1,2-a]pyridine.
Scheme 75: Mechanistic pathway.
Scheme 76: Mechanistic rationale for the synthesis of products.
Scheme 77: Copper-catalyzed synthesis of vinyloxy-IP.
Scheme 78: Regioselective product formation with propiolates.
Scheme 79: Proposed mechanism for vinyloxy-IP formation.
Scheme 80: Regioselective synthesis of 3-hetero-substituted imidazo[1,2-a]pyridines with different reaction su...
Scheme 81: Mechanistic pathway.
Scheme 82: CuI-mediated synthesis of 3-formylimidazo[1,2-a]pyridines.
Scheme 83: Radical pathway for 3-formylated IP synthesis.
Scheme 84: Pd-catalyzed urea-cyclization reaction for IPs.
Scheme 85: Pd-catalyzed one-pot-tandem amination and intramolecular amidation reaction.
Figure 5: Scope of aniline nucleophiles.
Scheme 86: Pd–Cu-catalyzed Sonogashira coupling reaction.
Scheme 87: One-pot amide coupling reaction for the synthesis of imidazo[4,5-b]pyridines.
Scheme 88: Urea cyclization reaction for the synthesis of two series of pyridines.
Scheme 89: Amidation reaction for the synthesis of imidazo[4,5-b]pyridines.
Figure 6: Amide scope.
Scheme 90: Pd NPs-catalyzed 3-component reaction for the synthesis of 2,3-diarylated IPs.
Scheme 91: Plausible mechanistic pathway for Pd NPs-catalyzed MCR.
Scheme 92: Synthesis of chromenoannulated imidazo[1,2-a]pyridines.
Scheme 93: Mechanism for the synthesis of chromeno-annulated IPs.
Scheme 94: Zinc oxide NRs-catalyzed synthesis of imidazo[1,2-a]azines/diazines.
Scheme 95: Zinc oxide-catalyzed isocyanide based GBB reaction.
Scheme 96: Reaction pathway for ZnO-catalyzed GBB reaction.
Scheme 97: Mechanistic pathway.
Scheme 98: ZnO NRs-catalyzed MCR for the synthesis of imidazo[1,2-a]azines.
Scheme 99: Ugi type GBB three-component reaction.
Scheme 100: Magnetic NPs-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 101: Regioselective synthesis of 2-alkoxyimidazo[1,2-a]pyridines catalyzed by Fe-SBA-15.
Scheme 102: Plausible mechanistic pathway for the synthesis of 2-alkoxyimidazopyridine.
Scheme 103: Iron-catalyzed synthetic approach.
Scheme 104: Iron-catalyzed aminooxygenation reaction.
Scheme 105: Mechanistic pathway.
Scheme 106: Rh(III)-catalyzed double C–H activation of 2-substituted imidazoles and alkynes.
Scheme 107: Plausible reaction mechanism.
Scheme 108: Rh(III)-catalyzed non-aromatic C(sp2)–H bond activation–functionalization for the synthesis of imid...
Scheme 109: Reactivity and selectivity of different substrates.
Scheme 110: Rh-catalyzed direct C–H alkynylation by Li et al.
Scheme 111: Suggested radical mechanism.
Scheme 112: Scandium(III)triflate-catalyzed one-pot reaction and its mechanism for the synthesis of benzimidazo...
Scheme 113: RuCl3-assisted Ugi-type Groebke–Blackburn condensation reaction.
Scheme 114: C-3 aroylation via Ru-catalyzed two-component reaction.
Scheme 115: Regioselective synthetic mechanism.
Scheme 116: La(III)-catalyzed one-pot GBB reaction.
Scheme 117: Mechanistic approach for the synthesis of imidazo[1,2-a]pyridines.
Scheme 118: Synthesis of imidazo[1,2-a]pyridine using LaMnO3 NPs under neat conditions.
Scheme 119: Mechanistic approach.
Scheme 120: One-pot 3-CR for regioselective synthesis of 2-alkoxy-3-arylimidazo[1,2-a]pyridines.
Scheme 121: Formation of two possible products under optimization of the catalysts.
Scheme 122: Mechanistic strategy for NiFe2O4-catalyzed reaction.
Scheme 123: Two-component reaction for synthesizing imidazodipyridiniums.
Scheme 124: Mechanistic scheme for the synthesis of imidazodipyridiniums.
Scheme 125: CuI-catalyzed arylation of imidazo[1,2-a]pyridines.
Scheme 126: Mechanism for arylation reaction.
Scheme 127: Cupric acetate-catalyzed double carbonylation approach.
Scheme 128: Radical mechanism for double carbonylation of IP.
Scheme 129: C–S bond formation reaction catalyzed by cupric acetate.
Scheme 130: Cupric acetate-catalyzed C-3 formylation approach.
Scheme 131: Control experiments for signifying the role of DMSO and oxygen.
Scheme 132: Mechanism pathway.
Scheme 133: Copper bromide-catalyzed CDC reaction.
Scheme 134: Extension of the substrate scope.
Scheme 135: Plausible radical pathway.
Scheme 136: Transannulation reaction for the synthesis of imidazo[1,5-a]pyridines.
Scheme 137: Plausible reaction pathway for denitrogenative transannulation.
Scheme 138: Cupric acetate-catalyzed C-3 carbonylation reaction.
Scheme 139: Plausible mechanism for regioselective C-3 carbonylation.
Scheme 140: Alkynylation reaction at C-2 of 3H-imidazo[4,5-b]pyridines.
Scheme 141: Two-way mechanism for C-2 alkynylation of 3H-imidazo[4,5-b]pyridines.
Scheme 142: Palladium-catalyzed SCCR approach.
Scheme 143: Palladium-catalyzed Suzuki coupling reaction.
Scheme 144: Reaction mechanism.
Scheme 145: A phosphine free palladium-catalyzed synthesis of C-3 arylated imidazopyridines.
Scheme 146: Palladium-mediated Buchwald–Hartwig cross-coupling reaction.
Figure 7: Structure of the ligands optimized.
Scheme 147: Palladium acetate-catalyzed direct arylation of imidazo[1,2-a]pyridines.
Scheme 148: Palladium acetate-catalyzed mechanistic pathway.
Scheme 149: Palladium acetate-catalyzed regioselective arylation reported by Liu and Zhan.
Scheme 150: Mechanism for selective C-3 arylation of IP.
Scheme 151: Pd(II)-catalyzed alkenylation reaction with styrenes.
Scheme 152: Pd(II)-catalyzed alkenylation reaction with acrylates.
Scheme 153: A two way mechanism.
Scheme 154: Double C–H activation reaction catalyzed by Pd(OAc)2.
Scheme 155: Probable mechanism.
Scheme 156: Palladium-catalyzed decarboxylative coupling.
Scheme 157: Mechanistic cycle for decarboxylative arylation reaction.
Scheme 158: Ligand-free approach for arylation of imidazo[1,2-a]pyridine-3-carboxylic acids.
Scheme 159: Mechanism for ligandless arylation reaction.
Scheme 160: NHC-Pd(II) complex assisted arylation reaction.
Scheme 161: C-3 arylation of imidazo[1,2-a]pyridines with aryl bromides catalyzed by Pd(OAc)2.
Scheme 162: Pd(II)-catalyzed C-3 arylations with aryl tosylates and mesylates.
Scheme 163: CDC reaction for the synthesis of imidazo[1,2-a]pyridines.
Scheme 164: Plausible reaction mechanism for Pd(OAc)2-catalyzed synthesis of imidazo[1,2-a]pyridines.
Scheme 165: Pd-catalyzed C–H amination reaction.
Scheme 166: Mechanism for C–H amination reaction.
Scheme 167: One-pot synthesis for 3,6-di- or 2,3,6-tri(hetero)arylimidazo[1,2-a]pyridines.
Scheme 168: C–H/C–H cross-coupling reaction of IPs and azoles catalyzed by Pd(II).
Scheme 169: Mechanistic cycle.
Scheme 170: Rh-catalyzed C–H arylation reaction.
Scheme 171: Mechanistic pathway for C–H arylation of imidazo[1,2-a]pyridine.
Scheme 172: Rh(III)-catalyzed double C–H activation of 2-phenylimidazo[1,2-a]pyridines and alkynes.
Scheme 173: Rh(III)-catalyzed mechanistic pathway.
Scheme 174: Rh(III)-mediated oxidative coupling reaction.
Scheme 175: Reactions showing functionalization of the product obtained by the group of Kotla.
Scheme 176: Mechanism for Rh(III)-catalyzed oxidative coupling reaction.
Scheme 177: Rh(III)-catalyzed C–H activation reaction.
Scheme 178: Mechanistic cycle.
Scheme 179: Annulation reactions of 2-arylimidazo[1,2-a]pyridines and alkynes.
Scheme 180: Two-way reaction mechanism for annulations reaction.
Scheme 181: [RuCl2(p-cymene)]2-catalyzed C–C bond formation reaction.
Scheme 182: Reported reaction mechanism.
Scheme 183: Fe(III) catalyzed C-3 formylation approach.
Scheme 184: SET mechanism-catalyzed by Fe(III).
Scheme 185: Ni(dpp)Cl2-catalyzed KTC coupling.
Scheme 186: Pd-catalyzed SM coupling.
Scheme 187: Vanadium-catalyzed coupling of IP and NMO.
Scheme 188: Mechanistic cycle.
Scheme 189: Selective C3/C5–H bond functionalizations by mono and bimetallic systems.
Scheme 190: rGO-Ni@Pd-catalyzed C–H bond arylation of imidazo[1,2-a]pyridine.
Scheme 191: Mechanistic pathway for heterogeneously catalyzed arylation reaction.
Scheme 192: Zinc triflate-catalyzed coupling reaction of substituted propargyl alcohols.
Beilstein J. Org. Chem. 2019, 15, 1552–1562, doi:10.3762/bjoc.15.158
Graphical Abstract
Scheme 1: Oxidation of alkanes with RuO4.
Scheme 2: Mechanisms for RuO4 oxidation of alkanes.
Scheme 3: Oxidation of saturated five-membered (hetero)cyclic compounds.
Scheme 4: Rate-limiting step for the oxidation of cyclopentane (R1), tetrahydrofuran (R2) and tetrahydrothiop...
Figure 1: Optimized (B3LYP-d3bj/Def2SVP/cpcm=MeCN) geometries of transition structures corresponding to the o...
Figure 2: ELF analysis for the oxidation of cyclopentane (R1). Left: evolution of the electron population alo...
Figure 3: ELF analysis for the oxidation of tetrahydrofuran (R2, A) and tetrahydrothiophene (R3, B). Left: ev...
Figure 4: ELF assignment of electrons to the Ru environment. C(Ru) corresponds to a monosynaptic core basin a...
Scheme 5: Rate-limiting step for the oxidation of N-methyl- and N-benzylpyrrolidines R4 and R5, respectively.
Figure 5: Energy profile for the oxidation of R4 and R5. Relative energies, calculated at the B3LYP-d3bj/Def2...
Figure 6: Optimized (B3LYP-d3bj/Def2SVP/cpcm=water) transition structures for the oxidation of R4 and R5.
Beilstein J. Org. Chem. 2019, 15, 1416–1424, doi:10.3762/bjoc.15.141
Graphical Abstract
Scheme 1: Stereospecific formation of α-enynes from alkynyloxiranes.
Scheme 2: Trapping experiments of the oxiranyllithium derived from cis or trans-alkynyloxiranes 1b, and their...
Scheme 3: Proposed mechanism for the rearrangement of alkynyloxiranes to α-enynes through metalation and bory...
Beilstein J. Org. Chem. 2019, 15, 1313–1320, doi:10.3762/bjoc.15.130
Graphical Abstract
Scheme 1: FCR of pyrene and phthalic anhydride.
Scheme 2: Scope of acylation reagents in FCR under mechanochemical activation conditions and comparison with ...
Scheme 3: Scope of aromatic substrates in FCR under mechanochemical activation conditions. aIsolated yields.
Scheme 4: Mechanochemical regiodirected FCR of anthracene dimer and succinic anhydride.
Scheme 5: Regioselectivity direction by protection of 9,10-anthracene ring positions.
Scheme 6: Double FCR of phthaloyl chloride and aromatics.
Figure 1: In situ Raman monitoring of reaction of phthalic anhydride with p-xylene.
Beilstein J. Org. Chem. 2019, 15, 1194–1202, doi:10.3762/bjoc.15.116
Graphical Abstract
Figure 1: Squalestatin S1/zaragozic acid A (1) and DDSQ (2).
Scheme 1: Carbonyl ylide cycloaddition–rearrangement to the squalestatin core [12,13].
Scheme 2: Tartrate alkylation strategy to cycloaddition substrate.
Scheme 3: Conversion of α-ketoester to α-diazoester.
Scheme 4: Seebach’s tartrate alkylation and rationalisation of stereoselectivity [17-19].
Scheme 5: Tartrate alkylation with a non-activated alkyl iodide.
Scheme 6: Alkylated tartrate to diazoester sequence.
Scheme 7: TES protection approach to the squalestatin core.
Scheme 8: Tartrate acetonide methylation.
Scheme 9: Tartrate alkylation with various alkyl halides.
Scheme 10: Rationalisation of dialkylation observations.
Scheme 11: Tartrate alkylation chemistry with more complex alkyl iodides [12,13].
Figure 2: Natural product examples containing the monoalkylated tartaric acid motif.
Scheme 12: Epimerisation of monoalkylated tartrates.
Beilstein J. Org. Chem. 2019, 15, 1107–1115, doi:10.3762/bjoc.15.107
Graphical Abstract
Scheme 1: Previously developed bis-nucleophile/bis-electrophile [3 + 2] annulations.
Scheme 2: Concept: [3 + 2] C–C/C–C vs C–C/O–C bond-forming annulations.
Figure 1: Examples of annulated cylopentanic (top) and furan-based (bottom) substructures in natural products....
Scheme 3: C–C/O–C bond forming annulations with dimethyl 3-oxoglutarate (1a).
Scheme 4: C–C/C–C bond-forming annulations with dimethyl 3-oxoglutarate (1a).
Scheme 5: C–C/C–O bond-forming annulations with various bis-nucleophiles.
Scheme 6: Decarboxylative rearrangement of 4a into 5a.
Scheme 7: Proposed mechanism for the Pd-catalyzed part of the [3 + 2] annulation reaction.
Scheme 8: Proposed mechanism for the temperature dependent cyclization part of the [3 + 2] annulation.
Beilstein J. Org. Chem. 2019, 15, 1032–1045, doi:10.3762/bjoc.15.101
Graphical Abstract
Figure 1: 2-Aminoimidazole alkaloids from marine sponges.
Figure 2: The Knoevenagel–Michael adduct [24] and expected products.
Scheme 1: The three component condensation of imidazo[1,2-a]pyridine, aldehydes and Meldrum’s acid described ...
Figure 3: Molecular structure of 1-([1,1'-biphenyl]-4-yl)-5-oxo-7-phenyl-6,7-dihydro-5H-pyrrolo[1,2-c]imidazo...
Scheme 2: Two forms of cation 9i.
Figure 4: Molecular structure of 3-(2-amino-4-phenyl-1H-imidazol-5-yl)-3-(p-tolyl)propanoic acid 11b accordin...
Scheme 3: Three forms of the compound 11b in the crystal phase.
Scheme 4: Synthesis of the mixture of compounds 13 and 14.
Figure 5: Molecular structure of aminoimidazo[1,2-c]pyrrole 16a according to X-ray diffraction data. Thermal ...
Scheme 5: Resonance structures of 16a.
Figure 6: 3,3’-Spirooxindole alkaloids.
Figure 7: Molecular structure of aminoimidazo[1,2-c]pyrrole 19a according to X-ray diffraction data. Thermal ...
Scheme 6: Resonance structures of 19a.
Beilstein J. Org. Chem. 2018, 14, 3018–3024, doi:10.3762/bjoc.14.281
Graphical Abstract
Scheme 1: The nucleofugal carbanion unit C escapes from the alkoxides A1M1 or A1M2 (M = metal), generating th...
Scheme 2: Preparation of β-shielded α-lithioacrylonitrile 2Li and its reaction with aldehydes 4–6 to adducts 7...
Scheme 3: Reversible formation of the adduct 13 of adamantan-2-one (11).
Scheme 4: Preparation and cleavage of the adduct 18 of fluoren-9-one (15).
Scheme 5: Proton transfer from dicyclopropyl ketone (19) to 2Li.
Scheme 6: Metal-free release of the carbanion unit in 25 and its seizure by t-BuCH=O (→ 7); Bu = n-butyl.
Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221
Graphical Abstract
Scheme 1: Optimization of the Co-catalyzed carboxylation of 1a.
Scheme 2: Co-catalyzed carboxylation of propargyl acetates 1.
Scheme 3: Plausible reaction mechanism for the Co-catalyzed carboxylation of propargyl acetates 1.
Scheme 4: Optimization of the Co-catalyzed carboxylation of 3a.
Scheme 5: Co-catalyzed carboxylation of vinyl triflates 3.
Scheme 6: Co-catalyzed carboxylation of a sterically hindered aryl triflate 5.
Scheme 7: Optimization of the Co-catalyzed carboxylation of 7a.
Scheme 8: Scope of the reductive carboxylation of α,β-unsaturated nitriles 7.
Scheme 9: Scope of the carboxylation of α,β-unsaturated carboxamides 9.
Scheme 10: Optimization of the Co-catalyzed carboxylation of 11a.
Scheme 11: Scope of the carboxylation of allylarenes 11.
Scheme 12: Scope of the carboxylation of 1,4-diene derivatives 14.
Scheme 13: Plausible reaction mechanism for the Co-catalyzed C(sp3)–H carboxylation of allylarenes.
Scheme 14: Optimization of the Co-catalyzed carboxyzincation of 16a.
Scheme 15: Derivatization of the carboxyzincated product.
Scheme 16: Co-catalyzed carboxyzincation of alkynes 16.
Scheme 17: Plausible reaction mechanism for the Co-catalyzed carboxyzincation of alkynes 16.
Scheme 18: Co-catalyzed four-component coupling of alkynes 16, acrylates 18, CO2, and zinc.
Scheme 19: Proposed reaction mechanism for the Co-catalyzed four-component coupling.
Scheme 20: Visible-light-driven hydrocarboxylation of alkynes.
Scheme 21: Visible-light-driven synthesis of γ-hydroxybutenolides from ortho-ester-substituted aryl alkynes.
Scheme 22: One-pot synthesis of coumarines and 2-quinolones via hydrocarboxylation/alkyne isomerization/cycliz...
Scheme 23: Proposed reaction mechanism for the Co-catalyzed carboxylative cyclization of ortho-substituted aro...
Scheme 24: Rh-catalyzed carboxylation of arylboronic esters 25.
Scheme 25: Rh-catalyzed carboxylation of alkenylboronic esters 27.
Scheme 26: Plausible reaction mechanism for the Rh-catalyzed carboxylation of arylboronic esters 25.
Scheme 27: Ligand effect on the Rh-catalyzed carboxylation of 2-phenylpyridine 29a.
Scheme 28: Rh-catalyzed chelation-assisted C(sp2)–H bond carboxylation with CO2.
Scheme 29: Reaction mechanism for the Rh-catalyzed C(sp2)–H carboxylation of 2-pyridylarenes 29.
Scheme 30: Carboxylation of C(sp2)–H bond with CO2.
Scheme 31: Carboxylation of C(sp2)–H bond with CO2.
Scheme 32: Reaction mechanism for the Rh-catalyzed C(sp2)–H carboxylation of 2-arylphenols 34.
Scheme 33: Hydrocarboxylation of styrene derivatives with CO2.
Scheme 34: Hydrocarboxylation of α,β-unsaturated esters with CO2.
Scheme 35: Asymmetric hydrocarboxylation of α,β-unsaturated esters with CO2.
Scheme 36: Proposed reaction mechanism for the Rh-catalyzed hydrocarboxylation of C–C double bonds with CO2.
Scheme 37: Visible-light-driven hydrocarboxylation with CO2.
Scheme 38: Visible-light-driven Rh-catalyzed hydrocarboxylation of C–C double bonds with CO2.
Scheme 39: Optimization of reaction conditions on the Rh-catalyzed [2 + 2 + 2] cycloaddition of diyne 42a and ...
Scheme 40: [2 + 2 + 2] Cycloaddition of diyne and CO2.
Scheme 41: Proposed reaction pathways for the Rh-catalyzed [2 + 2 + 2] cycloaddition of diyne and CO2.
Beilstein J. Org. Chem. 2018, 14, 2204–2211, doi:10.3762/bjoc.14.194
Graphical Abstract
Scheme 1: Fixation of CO2 (200 mL/min) by 1 under (a) dry and (b) wet conditions.
Figure 1: Zwitterion adduct 2 and bicarbonate salt 3 confirmed by elemental analysis.
Figure 2: 13C NMR spectra of (a) 1 observed in DMSO-d6, (b) 3' prepared with 2 and D2O observed in D2O, and (...
Figure 3: FTIR-ATR spectra of zwitterion adduct 2 and bicarbonate salt 3 expanded at the range of 1500–1800 cm...
Figure 4: 13C-CPMAS NMR spectra of zwitterion adduct 2 and bicarbonate salt 3 expanded at the range of 30–170...
Figure 5: The optimized geometries of zwitterion adduct 2 and bicarbonate salt 3 estimated by DFT calculation...
Figure 6: TGA trace of (a) zwitterion adduct 2 and (b) bicarbonate salt 3 observed under N2 flow (200 mL/min)...
Scheme 2: Proposal decomposition paths and theoretical weight loss values of (a) zwitterion adduct 2 and (b) ...
Beilstein J. Org. Chem. 2018, 14, 2012–2017, doi:10.3762/bjoc.14.176
Graphical Abstract
Figure 1: Precedent examples of catalytic allylic C(sp3)–H additions to carbonyl electrophiles.
Figure 2: Substrate scope for acetophenone derivatives. aPreparative scale synthesis using 1 mmol of 2a.
Figure 3: Substrate scope for α-olefins.
Figure 4: A possible catalytic cycle.
Beilstein J. Org. Chem. 2018, 14, 1972–1979, doi:10.3762/bjoc.14.172
Graphical Abstract
Scheme 1: ortho-Aminophenol derivatives.
Scheme 2: Rearrangement of N-acyloxyanilines.
Scheme 3: Mechanistic studies, reported in [13].
Scheme 4: Competitive experiments, reported in [13].
Scheme 5: Mechanism for rearrangement to the para-position.
Beilstein J. Org. Chem. 2018, 14, 1813–1825, doi:10.3762/bjoc.14.154
Graphical Abstract
Figure 1: The structures of hypervalent iodine (III) reagents [8].
Scheme 1: Hypervalent iodine(III)-catalyzed functionalization of alkenes.
Scheme 2: Catalytic sulfonyloxylactonization of alkenoic acids [43].
Scheme 3: Catalytic diacetoxylation of alkenes [46].
Scheme 4: Intramolecular asymmetric dioxygenation of alkenes [48,50].
Scheme 5: Intermolecular asymmetric diacetoxylation of styrenes [52].
Scheme 6: Diacetoxylation of alkenes with ester groups containing catalysts 17 [55].
Scheme 7: Intramolecular diamination of alkenes [56].
Scheme 8: Intramolecular asymmetric diamination of alkenes [57].
Scheme 9: Intermolecular asymmetric diamination of alkenes [58].
Scheme 10: Iodoarene-catalyzed aminofluorination of alkenes [60,61].
Scheme 11: Iodoarene-catalyzed aminofluorination of alkenes [62].
Scheme 12: Catalytic difluorination of alkenes with Selectfluor [63].
Scheme 13: Iodoarene-catalyzed 1,2-difluorination of alkenes [64].
Scheme 14: Iodoarene-catalyzed asymmetric fluorination of styrenes [64,65].
Scheme 15: Gem-difluorination of styrenes [67].
Scheme 16: Asymmetric gem-difluorination of cinnamic acid derivatives [68].
Scheme 17: Oxyarylation of alkenes [71].
Scheme 18: Asymmetric oxidative rearrangements of alkenes [72].
Scheme 19: Bromolactonization of alkenes [75].
Scheme 20: Bromination of alkenes [77,78].
Scheme 21: Cooperative strategy for the carbonylation of alkenes [79].
Beilstein J. Org. Chem. 2018, 14, 1743–1749, doi:10.3762/bjoc.14.148
Graphical Abstract
Scheme 1: Possible intermediates of the interaction of alkynyl compounds with Ar–Cu(III) species.
Scheme 2: Two possible reaction routes for the oxazoline formation explored by computations. The schemes indi...
Scheme 3: Free energy profiles for the possible reaction routes. The final energy state (−50.5 kcal/mol) is n...
Beilstein J. Org. Chem. 2018, 14, 1642–1654, doi:10.3762/bjoc.14.140
Graphical Abstract
Figure 1: Minimum structures of the most stable PVE–MeOH dimers obtained at the B3LYP-D3(BJ)/def2-TZVP level;...
Figure 2: Dispersion interaction density (DID) plots calculated at the LCCSD/VQZ-F12 level. The brown zones i...
Figure 3: FTIR spectra of the supersonic expansion of methanol (MeOH) and phenyl vinyl ether (PVE) at differe...
Figure 4: The IR/R2PI spectrum in the range of 3520–3750 cm−1 was obtained via the excitation energy of 36885...
Figure 5: A section of the experimental 2–8 GHz spectrum using a mixture of PVE and MeOH (3 million acquisiti...
Figure 6: UV/IR/UV spectrum of PVE–MeOH in the range of 3520–3750 cm−1; excitation laser: 36741 cm−1, ionizin...
Beilstein J. Org. Chem. 2018, 14, 1413–1420, doi:10.3762/bjoc.14.118
Graphical Abstract
Scheme 1: Nucleophilic and π-electrophilic characters of organometallics depending on the central metals.
Scheme 2: Ni/Cr or Co/Cr-catalyzed NHK reaction.
Scheme 3: Functionalization of alkynes via carbocobaltation.
Scheme 4: Cyclization/borylation of alkynyl iodoarenes using the Co/Cr catalyst.
Scheme 5: Three-component coupling of aryl iodides, arenes, and aldehydes using Co/Cr catalyst (this work).
Scheme 6: Screening of aldehydes in the Co/Cr-catalyzed three-component coupling reaction. All yields are det...
Scheme 7: Screening of aryl iodides in the Co/Cr-catalyzed three-component coupling reaction. All yields are ...
Scheme 8: Screening of allenes in the Co/Cr-catalyzed three-component coupling reaction. All yields are deter...
Scheme 9: Reversed diastereoselectivity using allenyl ethers 5 and 6. a4-chlorobenzaldehyde was used instead ...
Scheme 10: Stoichiometric reaction of phenylchromium(II or III) reagents (reaction 1) and the three-component ...
Scheme 11: The origin of the diastereoselectivity in the present three-component coupling.
Scheme 12: Plausible reaction mechanism of the three-component coupling.