Nickel-Catalyzed Sonogashira C(sp)–C(sp<sup>2</sup>) Coupling through Visible-Light Sensitization
作者:Da-Liang Zhu、Ruijie Xu、Qi Wu、Hai-Yan Li、Jian-Ping Lang、Hong-Xi Li
DOI:10.1021/acs.joc.0c01177
日期:2020.7.17
efficient method for visible-light-initiated, nickel-catalyzed Sonogashira C(sp)–C(sp2) coupling has been developed via an energy-transfer mode. Thioxanthen-9-one as a photosensitizer could significantly accelerate the arylation of alkynes with a wide range of (hetero)aryl halides in high yields. The cross-couplingreaction undergoes the stepwise oxidative addition of an arylhalide to nickel(0), transmetalation
Dual gold/photoredox-catalyzed C(sp)–H arylation of terminal alkynes with diazonium salts
作者:Adrian Tlahuext-Aca、Matthew N. Hopkinson、Basudev Sahoo、Frank Glorius
DOI:10.1039/c5sc02583d
日期:——
The arylation of alkyl and aromatic terminal alkynes by a dual gold/photoredoxcatalytic system is described. Using aryldiazonium salts as readily available aryl sources, a range of diversely-functionalized arylalkynes could be synthesized under mild, base-free reaction conditions using visible light from simple household sources or even sunlight. This process, which exhibits a broad scope and functional
描述了金/光氧化还原双催化系统对烷基和芳族末端炔烃的芳基化。使用芳基重氮盐作为容易获得的芳基源,可以使用来自简单家庭来源的可见光甚至阳光,在温和、无碱的反应条件下合成一系列不同官能化的芳基炔。该过程表现出广泛的范围和官能团耐受性,将双金/光氧化还原催化的转化范围扩大到涉及 C-H 键功能化的转化范围,并证明了该概念在以下条件下获得 Au I / Au III氧化还原化学的潜力:温和的氧化还原中性条件。
Microwave-promoted hydrogenation and alkynylation reactions with palladium-loaded multi-walled carbon nanotubes
Multi-walled carbon nanotubes loaded with Pd(0) clusters (average size distribution 9 nm) have been used under microwave irradiation as catalysts in hydrogenation and alkynylation reactions under “eco-friendly” conditions; reduced cinnamic esters and cross-coupled products were obtained in good yields; use of piperidine as the base provided, in a regiospecific process, novel doubly alkynylated compounds unambiguously characterized by NMR correlation experiments and X-ray diffraction.
Synergistic Catalysis in the Sonogashira Coupling Reaction: Quantitative Kinetic Investigation of Transmetalation
作者:Chuan He、Jie Ke、Huan Xu、Aiwen Lei
DOI:10.1002/anie.201207970
日期:2013.1.28
Rate‐limiting: The transmetalation step of the Sonogashiracouplingreaction has been established as the rate‐limiting step. This cross‐coupling has been demonstrated to be a Pd‐catalyzed and Cu‐catalyzed synergistic process, which exhibits a first‐order kinetic dependence on both the [Pd] and [Cu] catalysts (see scheme).
Electronic Regioselectivity of Diarylalkynes in Cobalt-Mediated Pauson–Khand Reaction: An Experimental and Computational Study with Para- and Meta-Substituted Diarylalkynes and Norbornene
Both steric and electronic factors of substituted alkynes are known to guide α/β-cyclopentenone regioselectivity in the cobalt-mediated Pauson–Khand reaction (PKR). In synthetic applications of the PKR, the steric factors can often override or render possible electronic effects. This study examined alkyne-dependent electronic regioselectivity of cyclopentenone formation in PKR with norbornene and sterically