文献类型：期刊文献

英文题名：Heck-type coupling vs. conjugate addition in phosphine-rhodium catalyzed reactions of aryl boronic acids with α,β-unsaturated carbonyl compounds: A systematic investigation

作者：Zou, Gang[1]; Guo, Jianping[1,2]; Wang, Zhiyong[1]; Huang, Wen[1,2]; Tang, Jie[2]

机构：[1] Laborotary of Advanced Materials, Department of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, China; [2] Department of Chemistry, East China Normal University, 3663 North Zhongshan Rd., Shanghai 200062, China

年份：2007

期号：28

起止页码：3055

外文期刊名：Dalton Transactions

收录：EI(收录号：20073110735370)

语种：英文

外文关键词：Catalysis - Ligands - pH effects - Phosphorus compounds - Reaction kinetics - Rhodium

摘要：The competition between Heck-type coupling and conjugate addition in phosphine-rhodium catalyzed reactions of aryl boronic acids with α,β-unsaturated carbonyls has been systematically investigated in a toluene-H2O biphasic system. Aside from the intrinsic nature of rhodium and the enolization of carbonyls, the phosphine supporting ligand on rhodium, the ratio of aryl boronic acid to α,β-unsaturated carbonyl and the pH value of the aqueous phase were found to affect the competition significantly. Highly selective rhodium-based catalyst systems have therefore been developed for both Heck-type coupling and conjugate addition by synergistically tuning the supporting ligand, the boronic acid to olefin ratio and other reaction conditions. Conjugate addition with selectivity >99% and Heck-type coupling with selectivity of up to 100%, 98% and 84% for acrylates, acrylamides and methyl vinyl ketone, respectively, could be achieved in the rhodium-catalyzed reactions of aryl boronic acids with α,β- unsaturated carbonyls using the corresponding optimized rhodium-based catalyst systems. ? The Royal Society of Chemistry.