β-diketone, and phenols with alkenyltriarylbismuthonium salts proceeded smoothly in the presence of 1,1,3,3-tetramethylguanidine to afford the corresponding α-alkenylated carbonyl compounds (β,γ-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.
在1,1,3,3-
四甲基胍存在下,β-
酮酯,
β-二酮和
苯酚与α-烯基三芳基双bis盐的直接α-烯基化反应顺利进行,得到相应的α-烯基化羰基化合物(β,γ-不饱和羰基化合物),收率高。三芳基双变异基的高离去能力是在温和条件下在
乙烯基碳上形成C-C键的关键驱动力。