A new, efficient method for direct alpha-alkenylation of beta-dicarbonyl compounds and phenols using alkenyltriarylbismuthonium salts.
Direct alpha-alkenylation of beta-keto esters, beta-diketone, and phenols with alkenyltriarylbismuthonium salts proceeded smoothly in the presence of 1,1,3,3-tetramethylguanidine to afford the corresponding alpha-alkenylated carbonyl compounds (beta,gamma-unsaturated carbonyl compounds) in good yields. The high leaving ability of the triarylbismuthonio group is a key driving force to achieve the C-C bond formation at the vinylic carbon under mild conditions.
Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan. matano@scl.kyoto-u.ac.jp
Yoshihiro
Y
Matano
Hiroshi
H
Imahori