文献类型：期刊文献

英文题名：N-Heterocyclic Carbene-Assisted, Bis(phosphine)nickel-Catalyzed Cross-Couplings of Diarylborinic Acids with Aryl Chlorides, Tosylates, and Sulfamates

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：79

期号：15

起止页码：7132

外文期刊名：JOURNAL OF ORGANIC CHEMISTRY

收录：;EI(收录号：20143218048304);WOS:【SCI-EXPANDED(收录号:WOS:000339983300036)，CCR-EXPANDED(收录号:WOS:000339983300036)】；

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：Sulfur compounds - Couplings - Nickel compounds - Phosphorus compounds - Catalysis - Catalyst activity - Chlorine compounds - Organic compounds

摘要：Efficient bis(phosphine)nickel-catalyzed cross-couplings of diarylborinic acids with aryl chlorides, tosylates, and sulfamates have been effected with an assistance of N-heterocyclic carbene (NHC) generated in situ from N,N'-dialkylimidazoliums, e.g., N-butyl-N'-methylimidazolium bromide ([Bmim]Br), in toluene using K3PO4 center dot 3H(2)O as base. In contrast to bis(NHC)nickel-catalyzed conventional Suzuki coupling of arylboronic acids, mono(NHC)bis(phosphine)nickel species generated in situ from Ni(PPh3)(2)Cl-2/[Bmim]Br displayed high catalytic activities in the cross-couplings of diarylborinic acids. The structural influences from diarylborinic acids were found to be rather small, while electronic factors from aryl chlorides, tosylates, and sulfamates affected the couplings remarkably. The couplings of electronically activated aryl chlorides, tosylates, and sulfamates could be efficiently effected with 1.5 mol % NiCl2(PPh3)(2)/[Bmim]Br as catalyst precursor to give the biaryl products in excellent yields, while 3-5 mol % loadings had to be used for the couplings of non- and deactivated ones. A small ortho-substitutent on the aromatic ring of aryl chlorides, tosylates, and sulfamates was tolerable. Applicability of the nickel-catalyzed cross-couplings in practical synthesis of fine chemicals has been demonstrated in process development for a third-generation topical retinoid, Adapalene.