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Search for "regioselective arylation" in Full Text gives 10 result(s) in Beilstein Journal of Organic Chemistry.
Pyridine C(sp2)–H bond functionalization under transition-metal and rare earth metal catalysis
- Haritha Sindhe,
- Malladi Mounika Reddy,
- Karthikeyan Rajkumar,
- Akshay Kamble,
- Amardeep Singh,
- Anand Kumar and
- Satyasheel Sharma
Beilstein J. Org. Chem. 2023, 19, 820–863, doi:10.3762/bjoc.19.62
- ). In 2015, a palladium-catalyzed cross dehydrogenative coupling of pyridine N-oxides with toluene for the regioselective arylation and benzylation of pyridine N-oxide was reported by Khan and co-workers [92] (Scheme 23). The authors have shown toluene 117 when used as benzyl and aryl source remained
Graphical Abstract
Figure 1: Representative examples of bioactive natural products and FDA-approved drugs containing a pyridine ...
Scheme 1: Classical and traditional methods for the synthesis of functionalized pyridines.
Scheme 2: Rare earth metal (Ln)-catalyzed pyridine C–H alkylation.
Scheme 3: Pd-catalyzed C–H alkylation of pyridine N-oxide.
Scheme 4: CuI-catalyzed C–H alkylation of N-iminopyridinium ylides with tosylhydrazones (A) and a plausible r...
Scheme 5: Zirconium complex-catalyzed pyridine C–H alkylation.
Scheme 6: Rare earth metal-catalyzed pyridine C–H alkylation with nonpolar unsaturated substrates.
Scheme 7: Heterobimetallic Rh–Al complex-catalyzed ortho-C–H monoalkylation of pyridines.
Scheme 8: Mono(phosphinoamido)-rare earth complex-catalyzed pyridine C–H alkylation.
Scheme 9: Rhodium-catalyzed pyridine C–H alkylation with acrylates and acrylamides.
Scheme 10: Ni–Al bimetallic system-catalyzed pyridine C–H alkylation.
Scheme 11: Iridium-catalyzed pyridine C–H alkylation.
Scheme 12: para-C(sp2)–H Alkylation of pyridines with alkenes.
Scheme 13: Enantioselective pyridine C–H alkylation.
Scheme 14: Pd-catalyzed C2-olefination of pyridines.
Scheme 15: Ru-catalyzed C-6 (C-2)-propenylation of 2-arylated pyridines.
Scheme 16: C–H addition of allenes to pyridines catalyzed by half-sandwich Sc metal complex.
Scheme 17: Pd-catalyzed stereodivergent synthesis of alkenylated pyridines.
Scheme 18: Pd-catalyzed ligand-promoted selective C3-olefination of pyridines.
Scheme 19: Mono-N-protected amino acids in Pd-catalyzed C3-alkenylation of pyridines.
Scheme 20: Amide-directed and rhodium-catalyzed C3-alkenylation of pyridines.
Scheme 21: Bimetallic Ni–Al-catalyzed para-selective alkenylation of pyridine.
Scheme 22: Arylboronic ester-assisted pyridine direct C–H arylation.
Scheme 23: Pd-catalyzed C–H arylation/benzylation with toluene.
Scheme 24: Pd-catalyzed pyridine C–H arylation with potassium aryl- and heteroaryltrifluoroborates.
Scheme 25: Transient activator strategy in pyridine C–H biarylation.
Scheme 26: Ligand-promoted C3-arylation of pyridine.
Scheme 27: Pd-catalyzed arylation of nicotinic and isonicotinic acids.
Scheme 28: Iron-catalyzed and imine-directed C–H arylation of pyridines.
Scheme 29: Pd–(bipy-6-OH) cooperative system-mediated direct pyridine C3-arylation.
Scheme 30: Pd-catalyzed pyridine N-oxide C–H arylation with heteroarylcarboxylic acids.
Scheme 31: Pd-catalyzed C–H cross-coupling of pyridine N-oxides with five-membered heterocycles.
Scheme 32: Cu-catalyzed dehydrative biaryl coupling of azine(pyridine) N-oxides and oxazoles.
Scheme 33: Rh(III)-catalyzed cross dehydrogenative C3-heteroarylation of pyridines.
Scheme 34: Pd-catalyzed C3-selective arylation of pyridines.
Scheme 35: Rhodium-catalyzed oxidative C–H annulation of pyridines to quinolines.
Scheme 36: Rhodium-catalyzed and NHC-directed C–H annulation of pyridine.
Scheme 37: Ni/NHC-catalyzed regio- and enantioselective C–H cyclization of pyridines.
Scheme 38: Rare earth metal-catalyzed intramolecular C–H cyclization of pyridine to azaindolines.
Scheme 39: Rh-catalyzed alkenylation of bipyridine with terminal silylacetylenes.
Scheme 40: Rollover cyclometallation in Rh-catalyzed pyridine C–H functionalization.
Scheme 41: Rollover pathway in Rh-catalyzed C–H functionalization of N,N,N-tridentate chelating compounds.
Scheme 42: Pd-catalyzed rollover pathway in bipyridine-6-carboxamides C–H arylation.
Scheme 43: Rh-catalyzed C3-acylmethylation of bipyridine-6-carboxamides with sulfoxonium ylides.
Scheme 44: Rh-catalyzed C–H functionalization of bipyridines with alkynes.
Scheme 45: Rh-catalyzed C–H acylmethylation and annulation of bipyridine with sulfoxonium ylides.
Scheme 46: Iridium-catalyzed C4-borylation of pyridines.
Scheme 47: C3-Borylation of pyridines.
Scheme 48: Pd-catalyzed regioselective synthesis of silylated dihydropyridines.
Efficient synthesis of 3,6,13,16-tetrasubstituted-tetrabenzo[a,d,j,m]coronenes by selective C–H/C–O arylations of anthraquinone derivatives
- Seiya Terai,
- Yuki Sato,
- Takuya Kochi and
- Fumitoshi Kakiuchi
Beilstein J. Org. Chem. 2020, 16, 544–550, doi:10.3762/bjoc.16.51
- ]. Anthraquinone was chosen as a convenient template for the PAH syntheses, because various anthraquinone derivatives possessing zero to four oxygen substituents at the ortho-positions are readily available and the regioselective arylation at the positions of either C–H or C–O bonds provided a variety of
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.
Copper-catalyzed remote C–H arylation of polycyclic aromatic hydrocarbons (PAHs)
- Anping Luo,
- Min Zhang,
- Zhangyi Fu,
- Jingbo Lan,
- Di Wu and
- Jingsong You
Beilstein J. Org. Chem. 2020, 16, 530–536, doi:10.3762/bjoc.16.49
- and 4i). Notably, 1-naphthamides with alkenyl (1l) and alkynyl (1m) groups were also suitable substrates for this direct C7−H arylation, affording 4k and 4l in good yields (Scheme 3, 4k and 4l). Furthermore, this Cu-catalyzed direct C−H arylation could tolerate other PAH substrates. The regioselective
- arylation of PAHs is challenging, and so far, there are no examples on the selective remote C–H arylation of phenanthrene-9-carboxamide, pyrene-1-carboxamide and fluoranthene-3-carboxamide. Gratifyingly, the remote C–H arylation of these PAH substrates occurred smoothly, giving the corresponding arylation
Graphical Abstract
Scheme 1: Direct C–H arylation of PAHs.
Scheme 2: Scope of aryliodonium salts. Reaction conditions: 1a (0.2 mmol), 2 (0.3 mmol) in DCE (1 mL) at 70 °...
Scheme 3: Scope of PAHs. Reaction conditions: 1 (0.2 mmol), 2a (0.3 mmol) in DCE (1 mL) at 70 °C under N2 for...
Scheme 4: Proposed catalytic cycle.
Figure 1: a) UV-visible absorption spectra of 4k, 4n and 4o in toluene (1 × 10−5 mol/L). b) Emission spectra ...
Regioselective Pd-catalyzed direct C1- and C2-arylations of lilolidine for the access to 5,6-dihydropyrrolo[3,2,1-ij]quinoline derivatives
- Hai-Yun Huang,
- Haoran Li,
- Thierry Roisnel,
- Jean-François Soulé and
- Henri Doucet
Beilstein J. Org. Chem. 2019, 15, 2069–2075, doi:10.3762/bjoc.15.204
- acetate bases in DMA was found to promote the regioselective arylation at α-position of the nitrogen atom of lilolidine with a wide variety of aryl bromides. From these α-arylated lilolidines, a second arylation at the β-position gives the access to α,β-diarylated lilolidines containing two different aryl
Graphical Abstract
Figure 1: Structures of lilolidine, tivantinib and tarazepide.
Scheme 1: Access to α- and β-arylated lilolidine derivatives.
Scheme 2: Synthesis of α-arylated lilolidine derivatives.
Scheme 3: Synthesis of α,β-di(hetero)arylated lilolidine derivatives.
Scheme 4: Synthesis of α,β-diarylated lilolidine derivatives via successive direct arylations.
Scheme 5: Synthesis of 5,6-dihydrodibenzo[a,c]pyrido[3,2,1-jk]carbazoles via successive direct arylations.
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
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.
Reactivity of bromoselenophenes in palladium-catalyzed direct arylations
- Aymen Skhiri,
- Ridha Ben Salem,
- Jean-François Soulé and
- Henri Doucet
Beilstein J. Org. Chem. 2017, 13, 2862–2868, doi:10.3762/bjoc.13.278
- groups on both coupling partners such as nitrile, acetyl or chloro. It should be mentioned that again a regioselective arylation at the C2-position of 3-chlorothiophene was observed affording 26 in 72% yield. Although the mechanism of these reactions was not elucidated, the catalytic cycle shown on
Graphical Abstract
Scheme 1: Reported Pd-catalyzed heteroarylations of bromoselenophenes.
Scheme 2: Palladium-catalyzed heteroarylations of 2-bromoselenophene. *: 110 °C
Scheme 3: Palladium-catalyzed 2,5-diheteroarylation of 2,5-dibromoselenophene.
Scheme 4: Synthesis of 2-aryl-5-(heteroaryl)selenophenes.
Scheme 5: Proposed catalytic cycle.
Efficient synthesis of π-conjugated molecules incorporating fluorinated phenylene units through palladium-catalyzed iterative C(sp2)–H bond arylations
- Fatiha Abdelmalek,
- Fazia Derridj,
- Safia Djebbar,
- Jean-François Soulé and
- Henri Doucet
Beilstein J. Org. Chem. 2015, 11, 2012–2020, doi:10.3762/bjoc.11.218
- ; aThe reaction was performed using 4 equiv of 1-methylpyrrole during 15 h. Pd-catalyzed second arylation of 1 and 2. i) PdCl(C3H5)(dppb) (2 mol %), KOAc (2 equiv), DMA, 150 °C, 16 h. aRegioselectivity (a:b) ratio determined from crude 1H NMR. Pd-catalyzed direct regioselective arylation of 1-methyl-2
- -(2,3,4-trifluorophenyl)pyrrole (4). i) PdCl(C3H5)(dppb) (2 mol %), KOAc (2 equiv), DMA, 150 °C, 16 h. Pd-catalyzed direct regioselective arylation of 3-(2,3,4-trifluorophenyl)thiophenes. i) PdCl(C3H5)(dppb) (2 mol %), KOAc (2 equiv), DMA, 150 °C, 16 h. Pd-catalyzed desulfitative direct arylations of
- heteroarenes using difluorobenzenesulfonyl chlorides as the arylating agents. i) PdCl2(CH3CN)2 (5 mol %), Li2CO3 (3 equiv), 1,4-dioxane, 140 °C, 48 h. Pd-catalyzed second direct regioselective arylation of difluorophenylheteroarenes 19-23. i) PdCl(C3H5)(dppb) (2 mol %), KOAc (2 equiv), DMA, 150 °C, 16 h. [a
Graphical Abstract
Figure 1: Different pathways for the synthesis of π-conjugated molecules incorporating fluorinated phenylene ...
Scheme 1: Pd-catalyzed desulfitative direct arylations of heteroarenes using 2,3,4-trifluorobenzenesulfonyl c...
Scheme 2: Pd-catalyzed second arylation of 1 and 2. i) PdCl(C3H5)(dppb) (2 mol %), KOAc (2 equiv), DMA, 150 °...
Scheme 3: Pd-catalyzed direct regioselective arylation of 1-methyl-2-(2,3,4-trifluorophenyl)pyrrole (4). i) P...
Scheme 4: Pd-catalyzed direct regioselective arylation of 3-(2,3,4-trifluorophenyl)thiophenes. i) PdCl(C3H5)(...
Scheme 5: Pd-catalyzed desulfitative direct arylations of heteroarenes using difluorobenzenesulfonyl chloride...
Scheme 6: Pd-catalyzed second direct regioselective arylation of difluorophenylheteroarenes 19-23. i) PdCl(C3H...
Scheme 7: Pd-catalyzed iterative direct arylations of heteroarenes–fluorobenzene triads and tetrad. i) PdCl2(...
Scheme 8: Reactivity of pentafluorobenzenesulfonyl chloride in Pd-catalyzed direct desulfitative arylation of...
Exploration of C–H and N–H-bond functionalization towards 1-(1,2-diarylindol-3-yl)tetrahydroisoquinolines
- Michael Ghobrial,
- Marko D. Mihovilovic and
- Michael Schnürch
Beilstein J. Org. Chem. 2014, 10, 2186–2199, doi:10.3762/bjoc.10.226
- –Hartwig coupling; C–C coupling; C–H functionalization; iron catalysis; regioselective arylation; Introduction 1,2,3,4-Tetrahydroisoquinolines (THIQs) are common substructures in natural products [1]. The structural motif of 1-(indol-3-yl)-THIQ is also found in compounds with biological activity, for
Graphical Abstract
Figure 1: General structures of biologically active dihydroisoquinolines, THIQs and 1,2-diarylindoles.
Scheme 1: Li’s THIQ indolation protocol.
Scheme 2: Possible strategies for the synthesis of target structure 1. Dashed arrows indicate literature-know...
Scheme 3: Nucleophilic substitution of DMEDA with 2-fluoro-3-iodopyridine (10).
Scheme 4: Decomposition of 1-(indol-3-yl)-THIQ 4d during N-arylation (monitored by GC–MS).
Scheme 5: Formation of byproduct 13 via benzylic oxidation.
Scheme 6: Routes towards 1,2-diarylindoles starting from indole; a: PhB(OH)2 (3 equiv), Pd(OAc)2 (5 mol %), A...
Scheme 7: Palladium-catalyzed C2-arylation attempt of 1-(1-phenylindol-3-yl)-N-Boc-THIQ.
Hindered aryl bromides for regioselective palladium-catalysed direct arylation at less favourable C5-carbon of 3-substituted thiophenes
- Rongwei Jin,
- Charles Beromeo Bheeter and
- Henri Doucet
Beilstein J. Org. Chem. 2014, 10, 1239–1245, doi:10.3762/bjoc.10.123
- organometallics reducing the number of steps to prepare these arylthiophenes. The regioselective arylation via a Pd-catalysed C–H bond activation at carbon C5 of 2-substituted thiophenes has been largely described in recent years [13][14][15][16][17][18][19][20][21][22]. On the other hand, the Pd-catalysed direct
- conditions for the regioselective arylation at carbons C2 or C5 of methyl 3-thiophenecarboxylate [23]. The reaction performed with Pd(PPh3)4 as the catalyst in toluene led selectively to the 2-arylated thiophene; whereas, the use of Pd2(dba)3 in NMP afforded a mixture of 2- and 5-arylated thiophenes in a 15
Graphical Abstract
Scheme 1: Regioselectivity of coupling reactions of 3-substituted thiophenes with aryl halides.
Scheme 2: Regioselectivity of the arylation of 2-methylthiophene with ortho-substituted aryl bromides.
Scheme 3: Direct arylation of 3-substituted thiophenes with 2-bromo-1,3-dichlorobenzene.
Scheme 4: Pd-catalysed C2-arylation of 8b with aryl bromides.
Palladium-catalyzed dual C–H or N–H functionalization of unfunctionalized indole derivatives with alkenes and arenes
- Gianluigi Broggini,
- Egle M. Beccalli,
- Andrea Fasana and
- Silvia Gazzola
Beilstein J. Org. Chem. 2012, 8, 1730–1746, doi:10.3762/bjoc.8.198
- -methyl-2-butene. Proposed mechanism of the N-indolyl prenylation. Regioselective arylation of indoles by dual C–H functionalization. Plausible mechanism of the selective indole arylation. Chemoselective cyclization of N-allyl-1H-indole-2-carboxamide derivatives. Intramolecular annulations of
Graphical Abstract
Scheme 1: Typical catalytic cycle for Pd(II)-catalyzed alkenylation of indoles.
Scheme 2: Application of Fujiwara’s reaction to electron-rich heterocycles.
Scheme 3: Regioselective alkenylation of the unprotected indole.
Scheme 4: Plausible mechanism of the selective indole alkenylation, adapted from [49].
Scheme 5: Directing-group control in intermolecular indole alkenylation.
Scheme 6: Direct C–H alkenylation of N-(2-pyridyl)sulfonylindole.
Scheme 7: N-Prenylation of indoles with 2-methyl-2-butene.
Scheme 8: Proposed mechanism of the N-indolyl prenylation.
Scheme 9: Regioselective arylation of indoles by dual C–H functionalization.
Scheme 10: Plausible mechanism of the selective indole arylation.
Scheme 11: Chemoselective cyclization of N-allyl-1H-indole-2-carboxamide derivatives.
Scheme 12: Intramolecular annulations of alkenylindoles.
Scheme 13: A mechanistic probe for intramolecular annulations of alkenylindoles, adapted from Ferreira et al. [66]....
Scheme 14: Asymmetric indole annulations catalyzed by chiral Pd(II) complexes.
Scheme 15: Aerobic Pd(II)-catalyzed endo cyclization and subsequent amide cleavage/ester formation.
Scheme 16: Synthesis of the pyrimido[3,4-a]indole skeleton by intramolecular C-2 alkenylation.
Scheme 17: Synthesis of azepinoindoles by oxidative Heck cyclization.
Scheme 18: Enantioselective synthesis of 4-vinyl-substituted tetrahydro-β-carbolines.
Scheme 19: Pd-catalyzed endo-cyclization of 3-alkenylindoles for the construction of carbazoles.
Scheme 20: Pd-catalyzed hydroamination of 2-indolyl allenamides.
Scheme 21: Amidation reaction of 1-allyl-2-indolecarboxamides.
Scheme 22: Intramolecular cyclization of N-benzoylindole.
Scheme 23: Intramolecular alkenylation/carboxylation of alkenylindoles.
Scheme 24: Intermolecular alkenylation/carboxylation of 2-substituted indoles.
Scheme 25: Mechanistic investigation of the cyclization/carboxylation reaction.
Scheme 26: Plausible catalytic cycle for the cyclization/carboxylation of alkenylindoles, adapted from Liu et ...
Scheme 27: Intramolecular domino reactions of indolylallylamides through alkenylation/halogenation or alkenyla...
Scheme 28: Proposed mechanism for the alkenylation/esterification process through iminium intermediates.
Scheme 29: Cyclization of 3-indolylallylcarboxamides involving 1,2-migration of the acyl group from spiro-inte...
Scheme 30: Domino reactions of 2-indolylallylcarboxamides involving N–H functionalization.
Scheme 31: Cyclization/acyloxylation reaction of 3-alkenylindoles.
Scheme 32: Doubly intramolecular C–H functionalization of a 2-indolylcarboxamide bearing two allylic groups.
