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Synthesis of the Multisubstituted Halogenated Olefins via Cross-Coupling of Dihaloalkenes with Alkylzinc Bromides

2005; American Chemical Society; Volume: 71; Issue: 1 Linguagem: Inglês

10.1021/jo051980e

1520-6904

Daniela Andrei, Stanislaw F. Wnuk,

Catalytic Cross-Coupling Reactions

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 Pd2(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 β,β-dichlorostyrene with organozinc reagent resulted in the formation of monocoupled product.