Remarkable Access To Fluoroalkylated Trisubstituted Alkenes Via Highly Stereoselective Cobalt-catalyzed Hydrosilylation Reaction Of Fluoroalkylated Alkynes

摘要

Hydrosilylation reaction of various fluoroalkylated alkynes with Et_3SiH in the presence of a catalytic amount of Co_2(CO)_8 was investigated. The hydrosilylation of the alkynes having fluoroalkyl and aryl groups took place smoothly with good regioselectivity (ca. 80:20). In sharp contrast, the reaction of the alkynes having a fluoroalkyl group and a benzyl-type substituent, or various propargyl alcohols gave the corresponding vinylsilanes in an excellent regio- and stereoselective manner. Treatment of the vinylsilanes with various aldehydes in the presence of Zn(OTf)_2 and TBAF afforded the coupling products in good yields.