N‐heterocyclic carbene–palladium complexes for Suzuki–Miyaura coupling reaction with benzyl chloride and aromatic boronic acid leading to diarylmethanes
作者:Ming‐Tsz Chen、Wan‐Rong Wang、Yi‐Jun Li
DOI:10.1002/aoc.4912
日期:2019.6
A family of N‐heterocyclic carbene–palladium(II)–N,N‐dimethylbenzylamine complexes ((NHC)LPdCl2; L = N,N‐dimethylbenzylamine) were synthesized as well as characterized using single‐crystal X‐ray diffraction and spectroscopic data. These complexes exhibited higher catalytic activities for the Suzuki reaction of benzyl chlorides to afford diarylmethanes under milder conditions than other efficient (NHC)LPdCl2
合成了N-杂环卡宾-钯(II)-N,N-二甲基苄胺络合物((NHC)LPdCl 2 ; L = N,N-二甲基苄胺)并使用单晶X射线衍射和光谱进行了表征数据。与其他有效的(NHC)LPdCl 2络合物相比,这些络合物在温和的条件下对苄基氯的Suzuki反应表现出更高的催化活性,从而生成二芳基甲烷。使用最佳条件,可以以中等至高收率获得预期的偶联产物。所有反应均在空气中进行,所有起始原料均不经纯化直接使用。
The Dual Role of Benzophenone in Visible-Light/Nickel Photoredox-Catalyzed C−H Arylations: Hydrogen-Atom Transfer and Energy Transfer
作者:Abhishek Dewanji、Patricia E. Krach、Magnus Rueping
DOI:10.1002/anie.201901327
日期:2019.3.11
A dual catalytic protocol for the direct arylation of non‐activated C(sp3)−H bonds has been developed. Upon photochemical excitation, the excited triplet state of a diaryl ketone photosensitizer abstracts a hydrogen atom from an aliphatic C−H bond. This inherent reactivity was exploited for the generation of benzylic radicals which subsequently enter a nickel catalytic cycle, accomplishing the benzylic
photoredox catalyst proceed smoothly to give the corresponding alkyl‐substituted arenes in good to high yields. The present reaction system realizes a novel C−C bond‐forming reaction between two fragments generated from the C−C bond‐cleavage reactions of two independent substrates.
A palladiumcatalyzed Suzuki cross-coupling for construction of Csp3–Csp2 bond via Csp3–N bond activation of benzyltrimethyl-ammonium salt is described. This reaction not only offered a highly efficientapproach to diarylmethanes but also paved the way for the application of benzyltrimethylammonium salts in the palladiumcatalyzedcrosscouplingreactions.
Direct Method for Carbon-Carbon Bond Formation: The Functional Group Tolerant Cobalt-Catalyzed Alkylation of Aryl Halides
作者:Muriel Amatore、Corinne Gosmini
DOI:10.1002/chem.201000178
日期:2010.5.25
cobalt‐catalyzedalkylation of aryl halides has been developed that proceeds smoothly in the presence of phosphanes or bipyridines as ligands with a variety of alkylhalides, including challenging alkyl electrophiles bearing β‐hydrogen atoms (see scheme). Sensitive functional groups are tolerated on both coupling partners, thus, significantly extending the general scope of transition‐metal‐catalyzed