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Search for "C-arylation" in Full Text gives 10 result(s) in Beilstein Journal of Organic Chemistry.
Photoredox catalysis harvesting multiple photon or electrochemical energies
- Mattia Lepori,
- Simon Schmid and
- Joshua P. Barham
Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81
- enabling controlled bond activations [45]. Regarding the reductive C–C arylation, the application of the xanthene dye rhodamine 6G (Rh-6G) as a catalyst for the reduction of heteroarenes bearing two or three bromine atoms (e.g., 6) under irradiation with green light (λ = 530 nm) gave monosubstituted
Graphical Abstract
Figure 1: Oxidative and reductive activations of organic compounds harvesting photoredox catalysis.
Figure 2: General catalytic cycles of radical ion conPET (left) and radical ion e-PRC (right).
Figure 3: “Beginner’s guide”: comparison between advantages, capacities, and prospectives of conPET and PEC.
Figure 4: A) conPET reductive dehalogenation of aryl halides with PDI. B) Reductive C–H arylation with pyrrol...
Figure 5: A) Chromoselective mono- and disubstitution or polybrominated pyrimidines with pyrroles. B) Sequent...
Figure 6: A) Synthesis of pyrrolo[1,2-a]quinolines. B) Synthesis of ullazines.
Figure 7: A) Reductive phosphorylation of aryl halides via conPET. B) Selected examples from the substrate sc...
Figure 8: A) Reductive dehalogenation of aryl halides via conPET and selected examples from the substrate sco...
Figure 9: A) Reductive C–H arylation of aryl halides via conPET (top) and selected examples from the substrat...
Figure 10: A) Reductive hydrodehalogenation of aryl halides with Mes-Acr-BF4. B) Selected examples from the su...
Figure 11: A) Reductive hydrodechlorination of aryl chlorides with 4-DPAIPN. B) Proposed formation of CO2•−. C...
Figure 12: A) Reductive conPET borylation with 3CzEPAIPN (top) and selected examples from the substrate scope ...
Figure 13: Scale-up of conPET phosphorylation with 3CzEPAIPN.
Figure 14: A) Borylation of 1d. B) Characteristics and structure of PC1 with green and red parts showing the l...
Figure 15: A) Reductive C–H arylation scope with polysulfide conPET (top) and selected examples from the subst...
Figure 16: Scale-up of A) C–H arylation and B) dehaloborylation with polysulfide photocatalysis in continuous-...
Figure 17: A) Formation of [Ir1]0 and [Ir2]0 upon PET between [Ir1]+ and Et3N. B) Mechanism of multi-photon ta...
Figure 18: A) Reductive hydrodehalogenation of aryl halides via multi-photon tandem photocatalysis. B) Selecte...
Figure 19: A) Carbonylative amidation of aryl halides in continuous flow. B) Selected examples from the substr...
Figure 20: A) General scheme for reductive (RQ) and oxidative quenching (OQ) protocols using [FeIII(btz)3](PF6)...
Figure 21: A) Carbonylative amidation of alkyl iodides with [IrIII(ppy)2(dtbbpy)]PF6. B) Selected examples fro...
Figure 22: A) Carboxylative C–N bond cleavage in cyclic amines. B) Selected examples from the substrate scope....
Figure 23: A) Formal reduction of alkenes to alkanes via transfer hydrogenation. B) Selected examples from the...
Figure 24: A) Birch-type reduction of benzenes with PMP-BPI. B) Selected examples from the substrate scope (sc...
Figure 25: Proposed mechanism of the OH− mediated conPET Birch-type reduction of benzene via generation of sol...
Figure 26: Reductive detosylation of N-tosylated amides with Mes-Acr-BF4. B) Selected examples from the substr...
Figure 27: A) Reductive detosylation of N-tosyl amides by dual PRC. B) Selected examples from the substrate sc...
Figure 28: A) Mechanism of the dual PRC based on PET between [Cu(dap)2]+ and DCA. B) Mechanism of the dual PRC...
Figure 29: A) N–O bond cleavage in Weinreb amides with anthracene. B) N–O bond cleavage in Weinreb amides rely...
Figure 30: A) Pentafluorosulfanylation and fluoride elimination. B) Mechanism of the pentafluorosulfanylation ...
Figure 31: A) α-Alkoxypentafluorosulfanylation (top) and selected examples from the substrate scope (bottom). ...
Figure 32: A) Oxidative amination of arenes with azoles catalyzed by N-Ph PTZ. B) Selected examples from the s...
Figure 33: A) C(sp3)–H bond activation by HAT via chloride oxidation by *N-Ph PTZ•+. B) Proposed mechanism for...
Figure 34: A) Recycling e-PRC C–H azolation of electron-rich arenes with pyrazoles using Mes-Acr+ as a photoca...
Figure 35: A) Radical ion e-PRC direct oxidation of unactivated arenes using TAC+ as an electro-activated phot...
Figure 36: A) Radical ion e-PRC direct oxidation of unactivated arenes using TPA as an electro-activated photo...
Figure 37: Proposed mechanism (top) and mode of preassembly (bottom).
Figure 38: A) Possible preassemblies of reactive (left) vs unreactive (right) arenes. B) Calculated spin densi...
Figure 39: A) Recycling e-PRC C(sp2 )–H acetoxylation of arenes using DDQ as a photocatalyst. B) Proposed cata...
Figure 40: Gram scale hydroxylation of benzene in a recirculated flow setup.
Figure 41: A) Radical ion e-PRC vicinal diamination of alkylarenes using TAC+ as an electro-activated photocat...
Figure 42: A) Sequential oxygenation of multiple adjacent C–H bonds under radical ion e-PRC using TAC+ as an e...
Figure 43: A) Enantioselective recycling e-PRC cyanation of benzylic C–H bonds using ADQS as photocatalyst. B)...
Figure 44: Proposed tandem mechanism by Xu and co-workers.
Figure 45: A) Enantioselective recycling e-PRC decarboxylative cyanation using Cu(acac)2, Ce(OTf)3 and a box l...
Figure 46: A) Enantioselective recycling e-PRC benzylic cyanation using Cu(MeCN)4BF4, box ligand and anthraqui...
Figure 47: A) Radical ion e-PRC acetoxyhydroxylation of aryl olefins using TAC+ as an electro-activated photoc...
Figure 48: Selected examples from the substrate scope.
Figure 49: Photoelectrochemical acetoxyhydroxylation in a recirculated flow setup.
Figure 50: A) Radical ion e-PRC aminooxygenation of aryl olefins using TAC+ as an electro-activated photocatal...
Figure 51: A) Recycling e-PRC C–H alkylation of heteroarenes with organic trifluoroborates using Mes-Acr+ as p...
Figure 52: A) Recycling e-PRC decarboxylative C–H alkylation of heteroarenes using CeCl3·7H2O as catalyst. B) ...
Figure 53: A) Recycling e-PRC decarboxylative C–H alkylation of heteroarenes using Fe(NH4)2(SO4)2·6H2O as cata...
Figure 54: A) Recycling e-PRC C–H alkylation of heteroarenes with alkyl oxalates and 4CzIPN as photocatalyst. ...
Figure 55: A) Recycling e-PRC decarboxylative C–H carbamoylation of heteroarenes using 4CzIPN as photocatalyst...
Figure 56: A) Photoelectrochemical HAT-mediated hydrocarbon activation via the chlorine radical. B) Proposed m...
Figure 57: A) Selected examples from the substrate scope. B) Gram and decagram scale semi-continuous flow PEC ...
Figure 58: A) Photoelectrochemical HAT-mediated dehydrogenative coupling of benzothiazoles with aliphatic C–H ...
Figure 59: A) Photoelectrochemical HAT activation of ethers using electro-activated TAC+ as photocatalyst. B) ...
Figure 60: Selected examples from the substrate scope.
Figure 61: A) Photoelectrochemical HAT-mediated synthesis of alkylated benzimidazo-fused isoquinolinones using...
Figure 62: A) Decoupled photoelectrochemical cerium-catalyzed oxydichlorination of alkynes using CeCl3 as cata...
Figure 63: Proposed decoupled photoelectrochemical mechanism.
Figure 64: A) Decoupled photoelectrochemical ring-opening bromination of tertiary cycloalkanols using MgBr2 as...
Figure 65: A) Recycling e-PRC ring-opening functionalization of cycloalkanols using CeCl3 as catalyst. B) Prop...
Figure 66: Selected examples from the substrate scope of the PEC ring-opening functionalization.
Figure 67: A) Radical ion e-PRC reduction of chloro- and bromoarenes using DCA as catalyst and various accepto...
Figure 68: A) Screening of different phthalimide derivatives as catalyst for the e-PRC reduction of aryl halid...
Figure 69: Screening of different organic catalysts for the e-PRC reduction of trialkylanilium salts.
Figure 70: A) e-PRC reduction of phosphonated phenols and anilinium salts. B) Selected examples from the subst...
Figure 71: A) ConPET and e-PRC reduction of 4-bromobenzonitrile using a naphthalene diimide (NDI) precatalyst ...
Figure 72: A) Radical ion e-PRC reduction of phosphinated aliphatic alcohols with n-BuO-NpMI as catalyst. B) C...
Figure 73: Selected examples from the substrate scope.
Figure 74: A) Recycling e-PRC reductive dimerization of benzylic chlorides using a [Cu2] catalyst. B) Proposed...
Figure 75: A) Decoupled photoelectrochemical C–H alkylation of heteroarenes through deamination of Katritzky s...
Figure 76: Proposed mechanism by Chen and co-workers.
Facile and diastereoselective arylation of the privileged 1,4-dihydroisoquinolin-3(2H)-one scaffold
- Dmitry Dar’in,
- Grigory Kantin,
- Alexander Bunev and
- Mikhail Krasavin
Beilstein J. Org. Chem. 2022, 18, 1070–1078, doi:10.3762/bjoc.18.109
- in the literature. While pondering possible solutions to fill this void, we drew inspiration in our recent success achieving direct Brønsted acid-catalyzed C-arylation of 4-diazo-isoquinoline-1,3-diones 7 [9] which are, in turn, obtainable via the Regitz diazo transfer reaction onto readily available
- optimum conditions for the C-arylation of diazo substrates 10 (60 equiv ArH, 1.5 equiv TfOH, DCM, rt, 15 min), we proceeded to investigate the scope of this transformation for 4-diazo-3(2H)-isoquinolones 10a–s as well as various arenes (Scheme 3). In all cases, this (generally high-yielding
- ) transformation resulted in the highly diastereoselective formation of C-arylation products 10 which in some cases was accompanied by a regioisomer formation (with respect to the entering arene moiety) and the formation of 3-isoquinolones 15 (isolated and characterized in several instances). Not unexpectedly
Graphical Abstract
Figure 1: Diverse bioactive compounds based on the privileged 1,4-DHIQ scaffold.
Figure 2: Strategy investigated in this work.
Scheme 1: Preparation of 3(2H)-isoquinolones 11. aObtained as a 10:1 mixture of regioisomers; purified by cry...
Scheme 2: Preparation of 4-diazo-3(2H)-isoquinolones 10. aConfirmed by single-crystal X-ray crystallography (...
Scheme 3: TfOH-promoted arylation of diazo substrates 10. aStructure confirmed by single-crystal X-ray analys...
Scheme 4: Unexpected outcome of the TfOH-promoted arylation of 10a with N-formyl-N-methylaniline giving rise ...
Scheme 5: Plausible mechanism for the conversion of diazo substrates 10 to 4-aryl products 9 (shown for ArH =...
Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage
- Gagandeep Kour Reen,
- Ashok Kumar and
- Pratibha Sharma
Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165
- ][42][43][44]. Various copper salts have been used as Lewis acid in homogeneous catalysis. CuO nanoparticles (NPs) were used for C–N, C–S, C–O cross-coupling reactions and C-arylation. Recently, exploiting the cross-coupling tendency of CuO NPs, Reddy et al. have reported their use as a heterogeneous
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.
One-pot preparation of 4-aryl-3-bromocoumarins from 4-aryl-2-propynoic acids with diaryliodonium salts, TBAB, and Na2S2O8
- Teppei Sasaki,
- Katsuhiko Moriyama and
- Hideo Togo
Beilstein J. Org. Chem. 2018, 14, 345–353, doi:10.3762/bjoc.14.22
- -alkynoates with N-bromosuccinimide (NBS) at rt [34], where those reactions proceed via radical spiro-cyclization and then radical 1,2-carboxyl group migration, were reported. On the other hand, diaryliodonium salts are very useful for the C-arylation of active CH groups, the O-arylation of OH groups, and the
Graphical Abstract
Scheme 1: One-pot preparation of 4-aryl-3-bromocoumarins 3 from 3-aryl-2-propynoic acids 1 with diphenyliodon...
Scheme 2: One-pot preparation of 3-bromo-4-phenylcoumarins 3a from 3-phenyl-2-propynoic acid (1a) with daryli...
Scheme 3: Derivatization of 3-bromo-4-phenylcoumarin.
Figure 1: ORTEP of 3-bromo-7-chloro-4-phenylcoumarin (3Da).
Scheme 4: Possible reaction pathway.
Synthesis of benzannelated sultams by intramolecular Pd-catalyzed arylation of tertiary sulfonamides
- Valentin A. Rassadin,
- Mirko Scholz,
- Anastasiia A. Klochkova,
- Armin de Meijere and
- Victor V. Sokolov
Beilstein J. Org. Chem. 2017, 13, 1932–1939, doi:10.3762/bjoc.13.187
- Göttingen, Germany 10.3762/bjoc.13.187 Abstract A new and efficient approach to five- and six-membered benzannelated sultams by intramolecular C-arylation of tertiary 1-(methoxycarbonyl)methanesulfonamides under palladium catalysis is described. In case of the α-toluenesulfonamide derivative, an unexpected
- trifluoroacetic acid [36]. Indeed, when 10a was treated with CF3CO2H in refluxing dichloromethane for 3 days, the deprotected sultam 23 was isolated in a good yield of 72% (Scheme 7). Conclusion In conclusion, the intramolecular palladium-catalyzed C-arylation of tertiary 1-(methoxycarbonyl)methanesulfonanilides
Graphical Abstract
Scheme 1: A previous and a new approach to arene-annelated sultams.
Scheme 2: Pd-catalyzed cyclization of (2-iodophenyl)sulfonamides 3 and 5.
Scheme 3: Preparation of 4-methoxybenzyl-protected methyl 2-(N-o-iodoarylsulfamoyl)acetates 8. Reagents and c...
Scheme 4: Synthesis of arene-annelated sultams 10 by Pd-catalyzed intramolecular arylation of a C–H acidic me...
Figure 1: Structure of methyl 5-chloro-1-(4-methoxybenzyl)-1,3-dihydrobenzo[c]isothiazole-3-carboxylate-2,2-d...
Scheme 5: Palladium-catalyzed transformation of N-(2-iodophenyl)-N-(4-methoxybenzyl-benzylsulfonamide 12. Ar ...
Scheme 6: Palladium-catalyzed intramolecular arylation to yield a benzannelated six-membered sultam 21. Ar = ...
Scheme 7: An attempted and a successful removal of the PMB group from the sultam 10a.
Figure 2: Structure of methyl 1-(4-methoxybenzyl)-3-(nitrooxy)-1,3-dihydrobenzo[c]isothiazole-3-carboxylate-2...
Silyl-protective groups influencing the reactivity and selectivity in glycosylations
- Mikael Bols and
- Christian Marcus Pedersen
Beilstein J. Org. Chem. 2017, 13, 93–105, doi:10.3762/bjoc.13.12
- , the ability of the bulky silyl groups to alter the conformation of the glycosyl-donor ring can be used to control the selectivity. Suzuki and collaborators showed that the C-arylation reactions with the 3,4-O-di(tert-butyldiphenylsilyl)-protected acetate 56 led to the α-glycoside 58 with high
- thioglycoside 41. Regio- and stereoselective glycosylation using the superarmed thioglycoside donor 20. Superarmed donors used for C-arylation and the dependence of the size of the silylethers on the stereochemical outcome. β-Selective glucosylation with TIPS-protected glucosyl donors. The α-face is shielded by
Graphical Abstract
Figure 1: Silicon-protective groups typically used in carbohydrate chemistry.
Scheme 1: Glycosylation with sulfoxide 1.
Scheme 2: Glycosylation with imidate 4.
Scheme 3: Glycosylation with thioglycoside 7.
Scheme 4: In situ formation of a silylated lactosyl iodide for the synthesis of α-lactosylceramide.
Figure 2: Comparison of the reactivity of glycosyl donors with the pKa of the corresponding piperidinium ions....
Figure 3: Conformational change induced by bulky vicinal protective groups such as TBS, TIPS and TBDPS. The v...
Scheme 5: An example of a “one pot one addition” glycosylation, where 3 glucosyl donors are mixed with 2.1 eq...
Scheme 6: Superarmed-armed glycosylation with thioglycoside 34.
Scheme 7: One-pot double glycosylation with the conformationally armed thioglycoside 37.
Scheme 8: Superarmed-armed glycosylation with thioglycoside 41.
Figure 4: Donors disarmed by the di-tert-butylsilylene protective group.
Figure 5: The influence of a 3,6-O-tethering on anomeric reactivity and glycosylation selectivity. The α-thio...
Scheme 9: Regio- and stereoselective glycosylation using the superarmed thioglycoside donor 20.
Scheme 10: Superarmed donors used for C-arylation and the dependence of the size of the silylethers on the ste...
Scheme 11: β-Selective glucosylation with TIPS-protected glucosyl donors. The α-face is shielded by the bulky ...
Scheme 12: β-Selective rhamnosylation with a conformationally inverted donor.
Scheme 13: α-Selective galactosylation with DTBS-protected galactosyl donors.
Scheme 14: β-Selective arabinofuranosylation with a DTBS-protected donor.
Scheme 15: α-Selective glycosylation with a TIPDS-protected glucal donor.
Scheme 16: Highly β-selective glucuronylation using a 2,4-DTBS-tethered donor.
Recent advances in copper-catalyzed asymmetric coupling reactions
- Fengtao Zhou and
- Qian Cai
Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280
- synthesis of chiral biphenyl diphosphine ligands by means of an intramolecular Ullmann coupling with the introduction of chiral bridged ethers. Catalytic asymmetric C–C coupling In 1929, Hurtley reported the first example of a C-arylation reaction of malonic esters with 2-bromobenzoic acid using a catalytic
Graphical Abstract
Scheme 1: Copper-catalyzed asymmetric preparation of biaryl diacids by Ullmann coupling.
Scheme 2: Intramolecular biaryl coupling of bis(iodotrimethoxybenzoyl)hexopyranose derivatives.
Scheme 3: Preparation of 3,3’-disubstituted MeO-BIPHEP derivatives.
Scheme 4: Enantioselective synthesis of trans-4,5,9,10-tetrahydroxy-9,10-dihydrophenanthrene.
Scheme 5: Copper-catalyzed coupling of oxazoline-substituted aromatics to afford biaryl products with high di...
Scheme 6: Total synthesis of O-permethyl-tellimagrandin I.
Scheme 7: Total synthesis of (+)-gossypol.
Scheme 8: Total synthesis of (−)-mastigophorene A.
Scheme 9: Total synthesis of isokotanin.
Scheme 10: Synthesis of dimethyl[7]thiaheterohelicenes.
Scheme 11: Intramolecular coupling with chiral ortho-substituents.
Scheme 12: Chiral 1,3-diol-derived tethers in the diastereoselective synthesis of biaryl compounds.
Scheme 13: Synthesis of chiral unsymmetrically substituted biaryl compounds.
Scheme 14: Atroposelective synthesis of biaryl ligands and natural products by using a chiral diether linker.
Scheme 15: Enantioselective arylation reactions of 2-methylacetoacetates.
Scheme 16: Asymmetric aryl C–N coupling reactions following a desymmetrization strategy.
Scheme 17: Construction of cyano-bearing all-carbon quaternary stereocenters.
Scheme 18: An unexpected inversion of the enantioselectivity in the asymmetric C–N coupling reactions using ch...
Scheme 19: Differentiation of two nucleophilic amide groups.
Scheme 20: Synthesis of spirobilactams through a double N-arylation reaction.
Scheme 21: Asymmetric N-arylation through kinetic resolution.
Scheme 22: Formation of cyano-substituted quaternary stereocenters through kinetic resolution.
Scheme 23: Copper-catalyzed intramolecular desymmetric aryl C–O coupling.
Scheme 24: Transition metal-catalyzed allylic substitutions.
Scheme 25: Copper-catalyzed asymmetric allylic substitution of allyl phosphates.
Scheme 26: Allylic substitution of allyl phosphates with allenylboronates.
Scheme 27: Allylic substitution of allyl phosphates with vinylboron.
Scheme 28: Allylic substitution of allyl phosphates with vinylboron.
Scheme 29: Construction of quaternary stereogenic carbon centers through enantioselective allylic cross-coupli...
Scheme 30: Cu-catalyzed enantioselective allyl–allyl cross-coupling.
Scheme 31: Cu-catalyzed enantioselective allylic substitutions with silylboronates.
Scheme 32: Asymmetric allylic substitution of allyl phosphates with silylboronates.
Scheme 33: Stereoconvergent synthesis of chiral allylboronates.
Scheme 34: Enantioselective allylic substitutions with diboronates.
Scheme 35: Enantioselective allylic alkylations of terminal alkynes.
Synthesis of diverse indole libraries on polystyrene resin – Scope and limitations of an organometallic reaction on solid supports
- Kerstin Knepper,
- Sylvia Vanderheiden and
- Stefan Bräse
Beilstein J. Org. Chem. 2012, 8, 1191–1199, doi:10.3762/bjoc.8.132
- ], palladium-catalyzed indole synthesis [34][35][36][37][38][39][40], cycloaddition strategies [41], C-arylation of substituted acetonitriles or 1,3-dicarbonyl compounds [42], halocyclization [43][44] and finally, reduction of ortho-fluoro-nitroarenes [42]. The significant biological properties and the
Graphical Abstract
Scheme 1: Diverse synthesis of indoles using Bartoli reactions. aSee [24].
Figure 1: Nitroarenes on solid supports. In red: Nitroarenes failed to give indoles. aResin has been reported...
Figure 2: Temperature optimization with Grignard reagent 2{b}.
Figure 3: Temperature optimization with Grignard reagent 2{a}. Isolated yield.
Figure 4: Optimization studies of ester 1{h} with a Grignard reagent 2{d} to give indole 3{h,d} and methyl 3-...
Scheme 2: Stille reaction on solid supports.
Scheme 3: Suzuki reaction on solid supports.
Scheme 4: Sonogashira–Hagihara reaction on solid supports.
Amines as key building blocks in Pd-assisted multicomponent processes
- Didier Bouyssi,
- Nuno Monteiro and
- Geneviève Balme
Beilstein J. Org. Chem. 2011, 7, 1387–1406, doi:10.3762/bjoc.7.163
- a Pd-catalyzed cascade sequence, involving an alkenyl amination, a C-arylation and a subsequent intramolecular N-arylation, was developed by Barluenga and coworkers for the preparation of indole derivatives 68 [37]. Here, equimolecular amounts of haloalkene 65, o-dihaloarene 66, and amines are mixed
- -alkynylindoles through a Pd-catalyzed Sonogashira/double C–N coupling reaction. Synthesis of indoles through a Pd-catalyzed sequential alkenyl amination/C-arylation/N-arylation. Synthesis of N-aryl-2-benzylpyrrolidines through a sequential N-arylation/carboamination reaction. Synthesis of phenothiazine
- basic media. A subsequent Pd-mediated intermolecular alkylation with the dihalogeno substrate followed by an intramolecular N-arylation furnished 2-substituted indoles 68. In this cascade reaction, the palladium catalyst intervenes in three different coupling reactions: Intermolecular N-alkenylation, C
Graphical Abstract
Scheme 1: Synthesis of substituted amides.
Scheme 2: Synthesis of ketocarbamates and imidazolones.
Scheme 3: Access to β-lactams.
Scheme 4: Access to β-lactams with increased structural diversity.
Scheme 5: Synthesis of imidazolinium salts.
Scheme 6: Access to the indenamine core.
Scheme 7: Synthesis of substituted tetrahydropyridines.
Scheme 8: Synthesis of more substituted tetrahydropyridines.
Scheme 9: Synthesis of chiral tetrahydropyridines.
Scheme 10: Preparation of α-aminonitrile by a catalyzed Strecker reaction.
Scheme 11: Synthesis of spiroacetals.
Scheme 12: Synthesis of masked 3-aminoindan-1-ones.
Scheme 13: Synthesis of homoallylic amines and α-aminoesters.
Scheme 14: Preparation of 1,2-dihydroisoquinolin-1-ylphosphonates.
Scheme 15: Pyrazole elaboration by cycloaddition of hydrazines with alkynones generated in situ.
Scheme 16: An alternative approach to pyrazoles involving hydrazine cycloaddition.
Scheme 17: Synthesis of pyrroles by cyclization of propargyl amines.
Scheme 18: Isoindolone and phthalazone synthesis by cyclization of acylhydrazides.
Scheme 19: Sultam synthesis by cyclization of sulfonamides.
Scheme 20: Synthesis of sulfonamides by aminosulfonylation of aryl iodides.
Scheme 21: Pyrrolidine synthesis by carbopalladation of allylamines.
Scheme 22: Synthesis of indoles through a sequential C–C coupling/desilylation–coupling/cyclization reaction.
Scheme 23: Synthesis of indoles by a site selective Pd/C catalyzed cross-coupling approach.
Scheme 24: Synthesis of isoindolin-1-one derivatives through a sequential Sonogashira coupling/carbonylation/h...
Scheme 25: Synthesis of pyrroles through an allylic amination/Sonogashira coupling/hydroamination reaction.
Scheme 26: Synthesis of indoles through a Sonogashira coupling/cyclofunctionalization reaction.
Scheme 27: Synthesis of indoles through a one-pot two-step Sonogashira coupling/cyclofunctionalization reactio...
Scheme 28: Synthesis of α-alkynylindoles through a Pd-catalyzed Sonogashira/double C–N coupling reaction.
Scheme 29: Synthesis of indoles through a Pd-catalyzed sequential alkenyl amination/C-arylation/N-arylation.
Scheme 30: Synthesis of N-aryl-2-benzylpyrrolidines through a sequential N-arylation/carboamination reaction.
Scheme 31: Synthesis of phenothiazine derivatives through a one-pot palladium-catalyzed double C–N arylation i...
Scheme 32: Synthesis of substituted imidazolidinones through a palladium-catalyzed three-component reaction of...
Scheme 33: Synthesis of 2,3-diarylated amines through a palladium-catalyzed four-component reaction involving ...
Scheme 34: Synthesis of rolipram involving a Pd-catalyzed three-component reaction.
Scheme 35: Synthesis of seven-membered ring lactams through a Pd-catalyzed amination/intramolecular cyclocarbo...
C-Arylation reactions catalyzed by CuO-nanoparticles under ligand free conditions
- Mazaahir Kidwai,
- Saurav Bhardwaj and
- Roona Poddar
Beilstein J. Org. Chem. 2010, 6, No. 35, doi:10.3762/bjoc.6.35
- Mazaahir Kidwai Saurav Bhardwaj Roona Poddar Green Research Laboratory, Department ofChemistry, University of Delhi, Delhi, India 110007 10.3762/bjoc.6.35 Abstract CuO-nanoparticles were found to be an excellent heterogeneous catalyst for C-arylation of active methylene compounds using various
- aryl halides. The products were obtained in good to excellent yield. The catalyst can be recovered and reused for four cycles with almost no loss in activity. Keywords: active methylene compounds; C-arylation; heterogeneous catalyst; recyclability; Introduction Carbon-carbon (C–C) bond formation is
- one of the most important reactions in organic synthesis [1][2][3]. The resulting compounds formed from C–C coupling are valuable synthons in organic synthesis [4][5][6][7]. However, C-arylation reactions have not been investigated to the same extent as other C–C bond forming reactions. A great deal
Graphical Abstract
Scheme 1: Synthesis of 3-phenylpentane-2,4-dione using CuO-nanoparticles.
Figure 1: Powder X-ray diffraction pattern and TEM image of nano CuO (fresh).
Scheme 2: Synthesis of 3-phenylpentane-2,4-dione using CuO-nanoparticles.
Scheme 3: Synthesis of diethyl 2-aryl-malonate using CuO-nanoparticles.
Figure 2: Proposed reaction pathway for the CuO-nanoparticles catalyzed C–C coupling reaction.
Figure 3: Powder X-ray diffraction pattern and TEM image of recycled CuO-nanoparticles.
