N-heterocyclic carbene copper(I) complex-catalyzed direct C–H thiolation of benzothiazoles
摘要:
N-heterocyclic carbene (NHC) copper(I) complexes based on imidazol-2-ylidene and 1,2,3-triazol-5-ylidene catalyzed the direct C-H thiolation of benzothiazoles and benzoxazoles with aryl and alkyl thiols to give 2-aryl and 2-alkylthiobenzothiazoles in moderate-to-good yields. The NHC copper(I) complex [(IPr)CuI] was the most effective catalyst for the reaction among the NHC-Cu(I) complexes examined in this study. (C) 2013 Elsevier Ltd. All rights reserved.
Copper-catalysed synthesis of α-alkylidene cyclic carbonates from propargylic alcohols and CO<sub>2</sub>
作者:Alejandro Cervantes-Reyes、Kaveh Farshadfar、Matthias Rudolph、Frank Rominger、Thomas Schaub、Alireza Ariafard、A. Stephen K. Hashmi
DOI:10.1039/d0gc03990j
日期:——
propargylic alcohols and carbondioxide at room temperature. By using the combination of a sterically demanding BPDPrCuCl complex (BPDPr = 1,3-bis(2,6-diisopropylphenyl)-1,3-diazonine-2-ylidene) and CsF, as catalytic system, primary propargylic alcohols are efficiently converted to the corresponding α-alkylidenecycliccarbonates. Gram scale (up to 89% yield) and reusability experiments (74% global
[(NHC)CuX] complexes: Synthesis, characterization and catalytic activities in reduction reactions and Click Chemistry. On the advantage of using well-defined catalytic systems
作者:Silvia Díez-González、Eduardo C. Escudero-Adán、Jordi Benet-Buchholz、Edwin D. Stevens、Alexandra M. Z. Slawin、Steven P. Nolan
DOI:10.1039/c0dt00218f
日期:——
These complexes were then applied to two distinct organic reactions: the hydrosilylation of ketones and the 1,3-dipolar cycloaddition of azides and alkynes. In both transformations, outstanding catalytic systems were found for preparing the corresponding products in excellent yields and short reaction times. Most remarkably, the screening of well-defined systems in the hydrosilylation reaction allowed
This invention provides a process which comprises contacting, in a reaction zone, at least one organic azide, at least one alkyne, and at least one N-heterocyclic carbene copper compound in which the ligands are either (i) a halide and an N-heterocyclic carbene or (ii) two N-heterocyclic carbenes and a BF
4
−
or PF
6
−
anion, to form a 1,2,3-triazole in which at least the 1 and 4 positions each has a substituent. The N-heterocyclic carbene either an imidazol-2-ylidene in which the 1 and the 3 positions each has a substituent which has at least one carbon atom, or a 4,5-dihydro-imidazol-2-ylidene in which the 1 and the 3 positions each has a substituent which has at least one carbon atom.
Excited‐State Copper Catalysis for the Synthesis of Heterocycles
作者:Arghya Banerjee、Satavisha Sarkar、Jagrut A. Shah、Nicoline C. Frederiks、Emmanuel A. Bazan‐Bergamino、Christopher J. Johnson、Ming‐Yu Ngai
DOI:10.1002/anie.202113841
日期:2022.1.21
Visible-light-induced excited-state copper catalysis enables the synthesis of more than 10 distinct classes of heterocycles. The reaction tolerates a broad array of functional groups and complex molecular scaffolds, including derivatives of peptides, natural products, and marketed drugs.
A Masked Cuprous Hydride as a Catalyst for Carbonyl Hydrosilylation in Aqueous Solutions
作者:Florian Ritter、Debabrata Mukherjee、Thomas P. Spaniol、Alexander Hoffmann、Jun Okuda
DOI:10.1002/anie.201811890
日期:2019.2.4
[(IPr)Cu(HBPh3)] (IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene) with good thermal stability. Although this compound displays a contact ion‐pair structure, CuIH‐like catalytic activity was envisaged in carbonyl hydrosilylation. Sufficient moisture stability allowed the catalysis in aqueous/organic media. Mechanistic study further showed that a phenyl group on the borate anion is abstracted by [(IPr)Cu]+
氧化还原不稳定的氢化三苯硼酸亚铜被分离为具有良好热稳定性的N-杂环卡宾加合物[(IPr)Cu(HBPh 3)](IPr = 1,3-双(2,6-二异丙基苯基)咪唑-2-亚基)。尽管该化合物显示出接触离子对结构,但在羰基氢化硅烷化中仍可看到类似Cu I H的催化活性。足够的水分稳定性允许在水/有机介质中催化。机理研究进一步表明,[(IPr)Cu] +提取硼酸根阴离子上的苯基,得到阳离子有机铜络合物[(IPr)2 Cu 2(μ-Ph)] [BPh 4 ]。