Remarkable access to fluoroalkylated trisubstituted alkenes via highly stereoselective cobalt-catalyzed hydrosilylation reaction of fluoroalkylated alkynes
A novel synthetic approach to fluorine-containing acetylenic compounds based on Nicholas reaction
作者:Tsutomu Konno、Go Nagai、Takashi Ishihara
DOI:10.1016/j.jfluchem.2005.11.009
日期:2006.5
The fluorine-containing dicobalthexacarbonyl complex, prepared readily from γ-fluoroalkylated propargyl acetates and Co2(CO)8, reacted smoothly with various nucleophiles at the propargylic position, followed by oxidative decomplexation under the influence of Fe(NO3)3, to afford fluoroalkylated alkynes bearing various types of alkyl side chains in good to high yields.
Remarkable access to fluoroalkylated trisubstituted alkenes via highly stereoselective cobalt-catalyzed hydrosilylation reaction of fluoroalkylated alkynes
Hydrosilylation reaction of various fluoroalkylated alkynes with Et3SiH in the presence of a catalytic amount of Co2(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.