Synthesis of the Multisubstituted Halogenated Olefins via Cross-Coupling of Dihaloalkenes with Alkylzinc Bromides
作者:Daniela Andrei、Stanislaw F. Wnuk
DOI:10.1021/jo051980e
日期:2006.1.1
The 1-fluoro-1-haloalkenes undergo Pd-catalyzed Negishi cross-couplings with primary alkylzinc bromides to give multisubstituted fluoroalkenes. The alkylation was trans-selective giving pure Z-fluoroalkenes in most cases. The highest yields were obtained with Pd-2(dba)(3) and PdCl2(dppb) catalysts but the best stereochemical outcome was obtained with less reactive Pd(PPh3)(4). The tertiary alkylzincs also produced desired fluoroalkenes in high yields. Coupling of beta,beta-dichloro styrene with organozinc reagent resulted in the formation of monocoupled product.