文献类型：期刊文献

英文题名：N-Heterocyclic carbene/phosphite synergistically assisted Pd/C-catalyzed Suzuki coupling of aryl chlorides

作者：Ke, Haihua[1];Chen, Xiaofeng[1];Zou, Gang[1]

机构：[1]E China Univ Sci & Technol, Dept Fine Chem, Shanghai 200237, Peoples R China

年份：2014

卷号：28

期号：1

起止页码：54

外文期刊名：APPLIED ORGANOMETALLIC CHEMISTRY

收录：;EI(收录号：20135217119261);WOS:【SCI-EXPANDED(收录号:WOS:000328226600008)，CCR-EXPANDED(收录号:WOS:000328226600008)】；

基金：We are grateful for financial support provided by the National Science Foundation of China (No. 20972049).

语种：英文

外文关键词：Suzuki coupling; palladium on carbon; N-heterocyclic carbene; phosphite; aryl chloride

摘要：An N-heterocyclic carbene and phosphite synergistically enhanced Pd/C catalyst system has been developed for Suzuki coupling of aryl chlorides and aryl boronic acids from commercially available Pd/C with sterically demanding N,N-bis(2,6-diisopropylphenyl)imidazolylidene and trimethylphosphite. A remarkable increase in catalytic activity of Pd/C was observed when used along with 1 equiv. N,N-bis(2,6-diisopropylphenyl)imidazolium chloride and 2 equiv. phosphite with respect to palladium in appropriate solvents that were found to play a crucial role in Pd/C-NHC-P(OR)(3)-catalyzed Suzuki coupling. A dramatic ortho-substitution effect of carbonyl and nitrile groups in aryl chlorides was observed and explained by a modified quasi-heterogeneous catalysis mechanism. The Pd/C catalyst could be easily recovered from reaction mixtures by simple filtration and only low palladium contamination was detected in the biparyl products. A practical process for the synthesis of 4-biphenylcarbonitrile has therefore been developed using the N-heterocyclic carbene/phosphite-assisted Pd/C-catalyzed Suzuki coupling. Copyright (c) 2013 John Wiley & Sons, Ltd.