Search results
Search for "diarylacetylenes" in Full Text gives 10 result(s) in Beilstein Journal of Organic Chemistry.
Synthetic study of vic-bromination of diarylacetylenes, easy purification and separation
- Akane Togo,
- Hiyono Suzuki,
- Yuto Akai,
- Makoto Matsumoto,
- Yoshinori Suzuma,
- Hidehiko Kodama and
- Kouichi Matsumoto
Beilstein J. Org. Chem. 2026, 22, 795–802, doi:10.3762/bjoc.22.61
- , the E isomer could be recovered as a solid material by utilizing the difference in solubility. On the other hand, the Z isomer could be removed by filtration while remaining in solution. Keywords: bromination; diarylacetylenes; green chemistry; purification and separation; stereoselective reaction
- scope and limitations by using various diarylacetylenes bearing the substituents on the benzene ring at para-position. The results were summarized in Table 2. Depending on the product's characteristics, either heptane or methanol was used for purification and separation. The reaction of 1,2-di-p
- . In addition, heptane played an important and critical role for purification and separation of the crude product. Scope and limitations for bromination of various diarylacetylenes together with the gram-scale synthesis and control experiments were also investigated. These results and findings can
Graphical Abstract
Scheme 1: Selected and previous reports for bromination of diphenylacetylenes (a–c), and this work (d).
Scheme 2: Gram-scale synthesis of (a), and control experiments of (b), (c) and (d). n.r. = no reaction.
Scheme 3: Plausible reaction mechanism of the present reaction.
Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene
- Semyon V. Tsybulin,
- Ekaterina A. Filatova,
- Alexander F. Pozharskii,
- Valery A. Ozeryanskii and
- Anna V. Gulevskaya
Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49
- for these compounds were largely unaffected by HCl protonation, the UV spectra of the protonated forms were very similar to those of unsubstituted diphenylpolyynes attributing the above bands to a π→π* transition. Сomplete protonation of DMAN-based diarylacetylenes led to a hypsochromic shift of their
Graphical Abstract
Figure 1: Proton sponge-based 1,4-diaryl-1,3-butadiynes synthesized previously and in this study.
Figure 2: Target oligomers as push–pull and cross-conjugated π-systems.
Scheme 1: Synthetic strategy for target oligomers 5.
Scheme 2: Synthesis of 7-(arylethynyl)-2-ethynyl-DMAN 6.
Scheme 3: Synthesis of 1,4-diaryl-1,3-butadiynes 5 and their salts 11.
Figure 3: Molecular structures of compounds 5b (top), 5d (middle), and 5e (bottom).
Figure 4: Views on the molecular backbone of compounds 5b (top), 5d (middle), and 5e (bottom) along the napht...
Scheme 4: Transformation of butadiyne 5c into benzo[g]indole 12.
Figure 5: Molecular structure of compound 11c: frontal (top; BF4− omitted) and side views (bottom; hydrogen a...
Figure 6: Calculation of the qr parameter.
Figure 7: Two π-conjugation ways in oligomers 5.
Figure 8: UV–vis spectra of oligomers 5 (blue line), monomers 6 (red line), and butadiyne 1 (green line).
Figure 9: UV–vis spectra of salts 11 (left), 1·2HBF4 and 6b·HBF4 (right) in acetonitrile.
Figure 10: π-Conjugation pathway in salts 11b and 6b·HBF4.
Figure 11: Cyclic voltammograms of oligomers 5.
Scheme 5: Possible ways of one- and two-electron oxidation of oligomers 5.
Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes
- Almaz A. Zagidullin,
- Farida F. Akhmatkhanova,
- Mikhail N. Khrizanforov,
- Robert R. Fayzullin,
- Tatiana P. Gerasimova,
- Ilya A. Bezkishko and
- Vasili A. Miluykov
Beilstein J. Org. Chem. 2022, 18, 1338–1345, doi:10.3762/bjoc.18.139
- cation. Using this approach, tris(4-chlorophenyl)- and tris(3-chlorophenyl)cyclopropenyl bromides were prepared for the first time. The advantage of this approach is the possibility of synthesis of substituted diarylacetylenes, the corresponding substituted benzal chlorides, and triarylcyclopropenyl
- temperature to afford substituted diarylacetylenes 3. Based on this reaction, the desired compounds 3 were prepared from 2-chloro-, 3-chloro-, and 4-chlorophenyl aldehydes, respectively, in 3 steps in 10–53% yield (10% for 3a, 48% for 3b, 53% for 3c, Scheme 1). This method is an alternative way to different
- transition metal-catalyzed cross-coupling reactions broadly used for the preparation of different diarylacetylenes and, rarely, bis(chlorophenyl)acetylenes. Next, starting substituted benzaldehydes were treated with an excess of SOCl2 for 24 h at 25 °C. Corresponding substituted benzal chlorides 4 were
Graphical Abstract
Scheme 1: Synthesis of bis(chlorophenyl)acetylenes 3.
Scheme 2: Synthesis of 1,2,3-tris(chlorophenyl)cyclopropenylium bromides 5 and tributyl(1,2,3-tris(chlorophen...
Figure 1: ORTEP representations for cations 5c (a) and 6c (b) at the 50% probability level. Bromide anion and...
Scheme 3: Synthesis of 3,4,5-tris(chlorophenyl)-1,2-diphosphacyclopentadienides 7 and 3,4,5-tris(chlorophenyl...
Figure 2: Considered conformations of 8b-I and 8b-II.
Figure 3: Top: experimental UV–vis spectra of 8с (black) and 8b (red). Bottom: broadened calculated UV–vis sp...
Figure 4: Frontier orbitals of 8b-II contributing to absorption bands at about 380 nm.
Figure 5: Cyclic voltammograms of 3,4,5-triaryl-1,2-diphosphaferrocenes 8b and 8c in CH3CN on glassy carbon e...
A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles
- Pezhman Shiri,
- Ali Mohammad Amani and
- Thomas Mayer-Gall
Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114
- carrying alkyl substituents as well as electron-rich and electron-poor aryl groups afforded the corresponding products 142 in good to excellent yield. A moderate to good yield was achieved when numerous diarylacetylenes 141 substituted by 4-Me, 4-OMe, F, CF3, CO2Et, and CN were employed in this
- ]. First, the nanocatalyst 139 is inserted in the C–I bond to obtain the intermediate 143. Then, the insertion of diarylacetylenes 141 forms intermediate 144. In continuation, the acetate anion formed by reaction of AcOH with Et3N undergoes a ligand exchange with iodide to produce the intermediate 145
Graphical Abstract
Figure 1: Some significant triazole derivatives [8,23-27].
Scheme 1: A general comparison between synthetic routes for disubstituted 1,2,3-triazole derivatives and full...
Scheme 2: Synthesis of formyltriazoles 3 from the treatment of α-bromoacroleins 1 with azides 2.
Scheme 3: A probable mechanism for the synthesis of formyltriazoles 5 from the treatment of α-bromoacroleins 1...
Scheme 4: Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 8 from the reaction of aryl azides 7 with enamino...
Scheme 5: Proposed mechanism for the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles from the reaction of a...
Scheme 6: Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 11 from the reaction of primary amines 10 with 1,...
Scheme 7: The proposed mechanism for the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 11 from the reacti...
Scheme 8: Synthesis of fully decorated 1,2,3-triazoles 19 containing a sulfur-based side chain.
Scheme 9: Mechanism for the formation of fully decorated 1,2,3-triazoles 19 containing a sulfur-based side ch...
Scheme 10: Synthesis of fully decorated 1,2,3-triazole compounds 25 through the regioselective addition and cy...
Scheme 11: A reasonable mechanism for the synthesis of fully decorated 1,2,3-triazole compounds 25 through the...
Scheme 12: Synthesis of 1,4,5-trisubstituted glycosyl-containing 1,2,3-triazole derivatives 30 from the reacti...
Scheme 13: Synthesis of 1,4,5-trisubstituted 1,2,3-triazoles 34 via intramolecular cyclization reaction of ket...
Scheme 14: Synthesis of fully decorated 1,2,3-triazoles 38 from the reaction of aldehydes 35, amines 36, and α...
Scheme 15: A reasonable mechanism for the synthesis of fully decorated 1,2,3-triazoles 38 from the reaction of...
Scheme 16: Synthesis of functionally rich double C- and N-vinylated 1,2,3-triazoles 45 and 47.
Scheme 17: Synthesis of disubstituted 4-chloro-, 4-bromo-, and 4-iodo-1,2,3-triazoles 50.
Scheme 18: a) A general route for SPAAC in polymer chemistry and b) synthesis of a novel pH-sensitive polymeri...
Scheme 19: Synthesis of 5-allenyl-1,2,3-triazoles 60 by the treatment of alkynes 57, azides 58, and propargyli...
Scheme 20: A reasonable mechanism for the synthesis of 5-allenyl-1,2,3-triazoles 60 by the treatment of alkyne...
Scheme 21: Synthesis of 5‐alkynyl-1,2,3-triazoles 69.
Scheme 22: A reasonable mechanism for the synthesis of 5‐alkynyl-1,2,3-triazoles 69.
Scheme 23: Synthesis of sulfur-cycle-fused 1,2,3-triazoles 75 and 77.
Scheme 24: A reasonable mechanism for the synthesis of sulfur-cycle-fused 1,2,3‐triazoles 75 and 77.
Scheme 25: Synthesis of 5-selanyltriazoles 85 from the reaction of ethynylstibanes 82, organic azides 83, and ...
Scheme 26: A mechanism for the synthesis of 5-selanyltriazoles 85 from the reaction of ethynylstibanes 82, org...
Scheme 27: Synthesis of trisubstituted triazoles containing an Sb substituent at position C5 in 93 and 5-unsub...
Scheme 28: Synthesis of asymmetric triazole disulfides 98 from disulfide-containing tert-butyltosyl disulfide 97...
Scheme 29: A mechanism for the synthesis of asymmetric triazole disulfides 98 from disulfide-containing tert-bu...
Scheme 30: Synthesis of triazole-fused sultams 104.
Scheme 31: Synthesis of 1,2,3-triazole-fused tricyclic heterocycles 106.
Scheme 32: A reasonable mechanism for the synthesis of 1,2,3-triazole-fused tricyclic heterocycles 106.
Scheme 33: Synthesis of 5-aryl-substituted 1,2,3-triazole derivatives 112.
Scheme 34: A reasonable mechanism for the synthesis of 5-aryl-substituted 1,2,3-triazole derivatives 112.
Scheme 35: Synthesis of 1,4,5-trisubstituted 1,2,3-triazole-5-carboxamides 119.
Scheme 36: A probable mechanism for the synthesis of 1,4,5-trisubstituted 1,2,3-triazole-5-carboxamides 119.
Scheme 37: Synthesis of fully decorated triazoles 125 via the Pd/C-catalyzed arylation of disubstituted triazo...
Scheme 38: Synthesis of triazolo[1,5-a]indolones 131.
Scheme 39: Synthesis of unsymmetrically substituted triazole-fused enediyne systems 135 and 5-aryl-4-ethynyltr...
Scheme 40: Synthesis of Pd/Cu-BNP 139 and application of 139 in the synthesis of polycyclic triazoles 142.
Scheme 41: A probable mechanism for the synthesis of polycyclic triazoles 142.
Scheme 42: Synthesis of highly functionalized 1,2,3-triazole-fused 5-, 6-, and 7-membered rings 152–154.
Scheme 43: A probable mechanism for the synthesis of highly functionalized 1,2,3-triazole-fused 5-, 6-, and 7-...
Scheme 44: Synthesis of fully functionalized 1,2,3-triazolo-fused chromenes 162, 164, and 166 via the intramol...
Scheme 45: Ru-catalyzed synthesis of fully decorated triazoles 172.
Scheme 46: Synthesis of 4-cyano-1,2,3-triazoles 175.
Scheme 47: Synthesis of functionalized triazoles from the reaction of 1-alkyltriazenes 176 and azides 177 and ...
Scheme 48: Mechanism for the synthesis of functionalized triazoles from the reaction of 1-alkyltriazenes 176 a...
Efficient [(NHC)Au(NTf2)]-catalyzed hydrohydrazidation of terminal and internal alkynes
- Maximillian Heidrich and
- Herbert Plenio
Beilstein J. Org. Chem. 2020, 16, 2080–2086, doi:10.3762/bjoc.16.175
- diarylacetylenes was reacted with electronically variable benzohydrazides (4-R = NMe2, H, NO2), to cover a range of steric and electronic substituents. In case shorter reaction times were desired, this could be compensated by increasing the amount of catalyst or the reaction temperature. The order of the alkyne
Graphical Abstract
Scheme 1: Simplified mechanism of the hydrohydrazidation (NuH= ArCONHNH2) of alkynes.
Scheme 2: [(NHC)Au(NTf2)] complexes tested in hydrohydrazidation reactions of phenylacetylene.
Scheme 3: Hydrohydrazidation of terminal alkynes in chlorobenzene and anisole using complex 1 (first line sol...
Scheme 4: Hydrohydrazidation of internal alkynes in chlorobenzene and anisole using complex 1. Reaction tempe...
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.
Synthesis of spirocyclic scaffolds using hypervalent iodine reagents
- Fateh V. Singh,
- Priyanka B. Kole,
- Saeesh R. Mangaonkar and
- Samata E. Shetgaonkar
Beilstein J. Org. Chem. 2018, 14, 1778–1805, doi:10.3762/bjoc.14.152
- functionalized benzocoumarins to spirocyclic lactones. In 2015, Du and co-workers [74] reported a spirocyclization of diarylacetylenes to fused spiro polycyclic compounds through a hypervalent iodine-mediated cascade annulation reaction. In this reaction, the Lewis acid BF3·Et2O acts as catalyst which activates
Graphical Abstract
Figure 1: The structures of biologically active natural and synthetic products having spirocyclic moiety.
Scheme 1: Iodine(III)-mediated spirocyclization of substituted phenols 7 and 11 to 10 and 13, respectively.
Scheme 2: PIDA-mediated spirolactonization of N-protected tyrosine 14 to spirolactone 16.
Figure 2: The structures of polymer-supported iodine(III) reagents 17a and 17b.
Scheme 3: Spirolactonization of substrates 14 to spirolactones 16 using polymer-supported reagents 17a and 17b...
Scheme 4: PIDA-mediated spirolactonization of 1-(p-hydroxyaryl)cyclobutanols 18 to spirolactones 19.
Scheme 5: Iodine(III)-mediated spirocyclization of aryl alkynes 24 to spirolactones 26 by the reaction with b...
Scheme 6: Bridged iodine(III)-mediated spirocyclization of phenols 27 to spirodienones 29.
Scheme 7: Iodine(III)-mediated spirocyclization of arnottin I (30) to its spirocyclic analogue arnottin II (32...
Scheme 8: Iodine(III)-catalyzed spirolactonization of p-substituted phenols 27 to spirolactones 29 using iodo...
Scheme 9: Iodine(III)-catalyzed oxylactonization of ketocarboxylic acid 34 to spirolactone 36 using iodobenze...
Scheme 10: Iodine(III)-mediated asymmetric oxidative spirocyclization of naphthyl acids 37 to naphthyl spirola...
Scheme 11: Oxidative cyclization of L-tyrosine 14 to spirocyclic lactone 16 using PIDA (15).
Scheme 12: Oxidative cyclization of oxazoline derivatives 41 to spirolactams 42 using PIDA (15).
Scheme 13: Oxidative cyclization of oxazoline 43 to spirolactam 44 using PIDA 15 as oxidant.
Scheme 14: PIFA-mediated spirocyclization of amides 46 to N-spirolactams 47 using PIFA (31) as an electrophile....
Scheme 15: Synthesis of spirolactam 49 from phenolic enamide 48 using PIDA (15).
Scheme 16: Iodine(III)-mediated spirocyclization of alkyl hydroxamates 50 to spirolactams 51 using stoichiomet...
Scheme 17: PIFA-mediated cyclization of substrate 52 to spirocyclic product 54.
Scheme 18: Synthesis of spiro β-lactams 56 by oxidative coupling reaction of p-substituted phenols 55 using PI...
Scheme 19: Iodine(III)-mediated spirocyclization of para-substituted amide 58 to spirolactam 59 by the reactio...
Scheme 20: Iodine(III)-mediated synthesis of spirolactams 61 from anilide derivatives 60.
Scheme 21: PIFA-mediated oxidative cyclization of anilide 60 to bis-spirobisoxindole 61.
Scheme 22: PIDA-mediated spirocyclization of phenylacetamides 65 to spirocyclic lactams 66.
Scheme 23: Oxidative dearomatization of arylamines 67 with PIFA (31) to give dieniminium salts 68.
Scheme 24: PIFA-mediated oxidative spirocarbocyclization of 4-methoxybenzamide 69 with diphenylacetylene (70) ...
Scheme 25: Synthesis of spiroxyindole 75 using I2O5/TBHP oxidative system.
Scheme 26: Iodine(III)-catalyzed spirolactonization of functionalized amides 76 to spirolactones 77 using iodo...
Scheme 27: Intramolecular cyclization of alkenes 78 to spirolactams 80 using Pd(II) 79 and PIDA (15) as the ox...
Scheme 28: Iodine(III)-catalyzed spiroaminocyclization of amides 76 to spirolactam 77 using bis(iodoarene) 81 ...
Scheme 29: Iodine(III)-catalyzed spirolactonization of N-phenyl benzamides 82 to spirolactams 83 using iodoben...
Scheme 30: Iodine(III)-mediated asymmetric oxidative spirocyclization of phenols 84 to spirolactams 86 using c...
Scheme 31: Iodine(III)-catalyzed asymmetric oxidative spirocyclization of N-aryl naphthamides 87 to spirocycli...
Scheme 32: Cyclization of p-substituted phenolic compound 89 to spirolactam 90 using PIDA (15) in TFE.
Scheme 33: Iodine(III)-mediated synthesis of spirocyclic compound 93 from substrates 92 using PIDA (15) as an ...
Scheme 34: Iodine(III)-mediated spirocyclization of p-substituted phenol 48 to spirocyclic compound 49 using P...
Scheme 35: Bridged iodine(III)-mediated spirocyclization of O-silylated phenolic compound 96 in the synthesis ...
Scheme 36: PIFA-mediated approach for the spirocyclization of ortho-substituted phenols 98 to aza-spirocarbocy...
Scheme 37: Oxidative cyclization of para-substituted phenols 102 to spirocarbocyclic compounds 104 using Koser...
Scheme 38: Iodine(III)-mediated spirocyclization of aryl alkynes 105 to spirocarbocyclic compound 106 by the r...
Scheme 39: Iodine(III)-mediated spirocarbocyclization of ortho-substituted phenols 107 to spirocarbocyclic com...
Scheme 40: PIFA-mediated oxidative cyclization of substrates 110 to spirocarbocyclic compounds 111.
Scheme 41: Iodine(III)-mediated cyclization of substrate 113 to spirocyclic compound 114.
Scheme 42: Iodine(III)-mediated spirocyclization of phenolic substrate 116 to the spirocarbocyclic natural pro...
Scheme 43: Iodine(III)-catalyzed spirocyclization of phenols 117 to spirocarbocyclic products 119 using iodoar...
Scheme 44: PIFA-mediated spirocyclization of 110 to spirocyclic compound 111 using PIFA (31) as electrophile.
Scheme 45: PIDA-mediated spirocyclization of phenolic sulfonamide 122 to spiroketones 123.
Scheme 46: Iodine(III)-mediated oxidative spirocyclization of 2-naphthol derivatives 124 to spiropyrrolidines ...
Scheme 47: PIDA-mediated oxidative spirocyclization of m-substituted phenols 126 to tricyclic spiroketals 127.
Figure 3: The structures of chiral organoiodine(III) catalysts 129a and 129b.
Scheme 48: Iodine(III)-catalyzed oxidative spirocyclization of substituted phenols 128 to spirocyclic ketals 1...
Scheme 49: Oxidative spirocyclization of para-substituted phenol 131 to spirodienone 133 using polymer support...
Scheme 50: Oxidative cyclization of bis-hydroxynaphthyl ether 135 to spiroketal 136 using PIDA (15) as an elec...
Scheme 51: Oxidative spirocyclization of phenolic compound 139 to spirodienone 140 using polymer-supported PID...
Scheme 52: PIFA-mediated oxidative cyclization of catechol derived substrate 142 to spirocyclic product 143.
Scheme 53: Oxidative spirocyclization of p-substituted phenolic substrate 145 to aculeatin A (146a) and aculea...
Scheme 54: Oxidative spirocyclization of p-substituted phenolic substrate 147 to aculeatin A (146a) and aculea...
Scheme 55: Oxidative spirocyclization of p-substituted phenolic substrate 148 to aculeatin D (149) using elect...
Scheme 56: Cyclization of phenolic substrate 131 to spirocyclic product 133 using polymer-supported PIFA 150.
Scheme 57: Iodine(III)-mediated oxidative intermolecular spirocyclization of 7-methoxy-α-naphthol (152) to spi...
Scheme 58: Oxidative cyclization of phenols 155 to spiro-ketals 156 using electrophilic species PIDA (15).
Scheme 59: Iodine(III)-catalyzed oxidative spirocyclization of ortho-substituted phenols 158 to spirocyclic ke...
Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s
- Natalia A. Danilkina,
- Petr S. Vlasov,
- Semen M. Vodianik,
- Andrey A. Kruchinin,
- Yuri G. Vlasov and
- Irina A. Balova
Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43
- could also be defined as a type of sila-Sonogashira coupling [47][48], which is an extremely convenient method for the one-step synthesis of non-symmetrically substituted diarylacetylenes [49][50]. Mild conditions allowed carrying out both reactions chemoselectively leaving the bromine atom for further
Graphical Abstract
Figure 1: Recent examples of PAEs and their application for the detection of Hg2+ (a) [11], Ni2+ (b) [12], explosives...
Figure 2: Target structures of PAEs.
Scheme 1: Synthesis of cinnoline-containing PAEs 10a,b.
Figure 3: 1H NMR spectra of PAEs 10a,b solutions in CDCl3.
Figure 4: 13C NMR spectra of PAEs 10a,b solutions in CDCl3.
Figure 5: Irregular chain structure (nonequivalent structural units are marked in different colors).
Figure 6: Optical absorption spectra of PAEs 10a,b in THF solutions.
Figure 7: Emission spectra of PAEs 10a,b in THF solutions.
Figure 8: Optical absorption spectra of PAE 10a in THF before and after the addition of metal analytes.
Figure 9: Optical absorption spectra of PAE 10b in THF before and after the addition of metal analytes.
Figure 10: Emission spectra of PAE 10a in THF before and after the addition of metal ions.
Figure 11: Emission spectra of PAE 10b in THF before and after the addition of metal ions.
Figure 12: Optical absorption spectra of PAE 10a in THF before and after the addition of HCl (10 equiv).
Figure 13: Emission spectra of PAE 10a in THF before and after the addition of HCl (10 equiv).
Figure 14: Optical absorption spectra of PAE 10b in THF before after the addition of methanol solution of PdCl2...
Figure 15: Emission spectra of PAE 10b in THF before and after the addition of methanol solution of PdCl2.
Figure 16: Optical absorption spectra of cinnoline 4a in THF before and after the addition of aqueous solution...
Figure 17: Emission spectra of cinnoline 4a in THF before and after the addition of aqueous solution of PdCl2.
Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions
- Andrea Caporale,
- Stefano Tartaggia,
- Andrea Castellin and
- Ottorino De Lucchi
Beilstein J. Org. Chem. 2014, 10, 384–393, doi:10.3762/bjoc.10.36
- of symmetrical and unsymmetrical diarylacetylenes resides not only in its low cost, but also in the possibility to carry out a conventional and a decarboxylative Sonogashira coupling reaction in sequence at the two sp carbons with two different aryl halides. Therefore a disubstituted alkyne can be
Graphical Abstract
Scheme 1: Conventional (from the left) and decarboxylative (from the right) Pd-catalyzed Sonogashira coupling...
Scheme 2: Protection of propiolic acid with acetone.
Recent advances in transition-metal-catalyzed intermolecular carbomagnesiation and carbozincation
- Kei Murakami and
- Hideki Yorimitsu
Beilstein J. Org. Chem. 2013, 9, 278–302, doi:10.3762/bjoc.9.34
- -phenyl-1-octyne with 4c provided the corresponding alkylated products 4d exclusively without contamination by the hydromagnesiated products of alkynes. In contrast, Nakamura reported the iron-catalyzed hydromagnesiation of diarylacetylenes and diynes with ethylmagnesium bromide as a hydride donor without
Graphical Abstract
Scheme 1: Variation of substrates for carbomagnesiation and carbozincation in this article.
Scheme 2: Copper-catalyzed arylmagnesiation and allylmagnesiation of alkynyl sulfone.
Scheme 3: Copper-catalyzed four-component reaction of alkynyl sulfoxide with alkylzinc reagent, diiodomethane...
Scheme 4: Rhodium-catalyzed reaction of aryl alkynyl ketones with arylzinc reagents.
Scheme 5: Allylmagnesiation of propargyl alcohol, which provides the anti-addition product.
Scheme 6: Negishi’s total synthesis of (Z)-γ-bisabolene by allylmagnesiation.
Scheme 7: Iron-catalyzed syn-carbomagnesiation of propargylic or homopropargylic alcohol.
Scheme 8: Mechanism of iron-catalyzed carbomagnesiation.
Scheme 9: Regio- and stereoselective manganese-catalyzed allylmagnesiation.
Scheme 10: Vinylation and alkylation of arylacetylene-bearing hydroxy group.
Scheme 11: Arylmagnesiation of (2-pyridyl)silyl-substituted alkynes.
Scheme 12: Synthesis of tamoxifen from 2g.
Scheme 13: Controlling regioselectivity of carbocupration by attaching directing groups.
Scheme 14: Rhodium-catalyzed carbozincation of ynamides.
Scheme 15: Synthesis of 4-pentenenitriles through carbometalation followed by aza-Claisen rearrangement.
Scheme 16: Uncatalyzed carbomagnesiation of cyclopropenes.
Scheme 17: Iron-catalyzed carbometalation of cyclopropenes.
Scheme 18: Enantioselective carbozincation of cyclopropenes.
Scheme 19: Copper-catalyzed facially selective carbomagnesiation.
Scheme 20: Arylmagnesiation of cyclopropenes.
Scheme 21: Enantioselective methylmagnesiation of cyclopropenes without catalyst.
Scheme 22: Copper-catalyzed carbozincation.
Scheme 23: Enantioselective ethylzincation of cyclopropenes.
Scheme 24: Nickel-catalyzed ring-opening aryl- and alkenylmagnesiation of a methylenecyclopropane.
Scheme 25: Reaction mechanism.
Scheme 26: Nickel-catalyzed carbomagnesiation of arylacetylene and dialkylacetylene.
Scheme 27: Nickel-catalyzed carbozincation of arylacetylenes and its application to the synthesis of tamoxifen....
Scheme 28: Bristol-Myers Squibb’s nickel-catalyzed phenylzincation.
Scheme 29: Iron/NHC-catalyzed arylmagnesiation of aryl(alkyl)acetylene.
Scheme 30: Iron/copper-cocatalyzed alkylmagnesiation of aryl(alkyl)acetylenes.
Scheme 31: Iron-catalyzed hydrometalation.
Scheme 32: Iron/copper-cocatalyzed arylmagnesiation of dialkylacetylenes.
Scheme 33: Chromium-catalyzed arylmagnesiation of alkynes.
Scheme 34: Cobalt-catalyzed arylzincation of alkynes.
Scheme 35: Cobalt-catalyzed formation of arylzinc reagents and subsequent arylzincation of alkynes.
Scheme 36: Cobalt-catalyzed benzylzincation of dialkylacetylene and aryl(alkyl)acetylenes.
Scheme 37: Synthesis of estrogen receptor antagonist.
Scheme 38: Cobalt-catalyzed allylzincation of aryl-substituted alkynes.
Scheme 39: Silver-catalyzed alkylmagnesiation of terminal alkyne.
Scheme 40: Proposed mechanism of silver-catalyzed alkylmagnesiation.
Scheme 41: Zirconium-catalyzed ethylzincation of terminal alkenes.
Scheme 42: Zirconium-catalyzed alkylmagnesiation.
Scheme 43: Titanium-catalyzed carbomagnesiation.
Scheme 44: Three-component coupling reaction.
Scheme 45: Iron-catalyzed arylzincation reaction of oxabicyclic alkenes.
Scheme 46: Reaction of allenyl ketones with organomagnesium reagent.
Scheme 47: Regio- and stereoselective reaction of a 2,3-allenoate.
Scheme 48: Three-component coupling reaction of 1,2-allenoate, organozinc reagent, and ketone.
Scheme 49: Proposed mechanism for a rhodium-catalyzed arylzincation of allenes.
Scheme 50: Synthesis of skipped polyenes by iterative arylzincation/allenylation reaction.
Scheme 51: Synthesis of 1,4-diorganomagnesium compound from 1,2-dienes.
Scheme 52: Synthesis of tricyclic compounds.
Scheme 53: Manganese-catalyzed allylmagnesiation of allenes.
Scheme 54: Copper-catalyzed alkylmagnesiation of 1,3-dienes and 1,3-enynes.
Scheme 55: Chromium-catalyzed methallylmagnesiation of 1,6-diynes.
Scheme 56: Chromium-catalyzed allylmagnesiation of 1,6-enynes.
Scheme 57: Proposed mechanism of the chromium-catalyzed methallylmagnesiation.
