Synthesis of Multiply Substituted Alkylidene Silacyclohexadiene Derivatives via Palladium-Catalyzed Insertion of Alkynes into Alkylidene Silacyclobutenes
作者:Junhui Liu、Xiaohua Sun、Mikihiro Miyazaki、Lantao Liu、Congyang Wang、Zhenfeng Xi
DOI:10.1021/jo062583m
日期:2007.4.1
Palladium-catalyzed insertion of activated alkynes into silacyclobutene derivatives proceeded smoothly to afford exo-alkylidenesilacyclohexadiene derivatives of unique structure with diversified conjugation systems in high isolated yields. Interesting regioselectivity of insertion, which afforded only one regioisomer or a mixture of two or more regioisomers, was also observed.
Intramolecular Coupling of Alkynyl Groups of Bis(alkynyl)silane Mediated by Zirconocene Compounds: Formation of Silacyclobutene Derivatives
further treatment of the reaction mixture with PhI in the presence of a catalytic amount of Pd(PPh3)4 gave 1,3,4-triphenyl-1-silyl-1,3-butadiene compound 16. Zirconacyclopentadienes with an alkynylsilyl group at the α-position afforded zirconacyclohexadiene derivatives 19 in 82−98% yields. Wh...