A Facile Synthesis of 1,1-Difluoroallenes from Commercially Available 1,1,1-Trifluoro-2-iodoethane
作者:Junji Ichikawa、Ken Oh、Kohei Fuchibe
DOI:10.1055/s-0030-1258438
日期:2011.3
1,1-Difluoroallenes are synthesized in good yield via zinc-promoted 1,2-elimination of 3,3-difluoro-2-iodoallylic acetates, which are prepared by the reaction of aldehydes or ketones with 1-iodo-2,2-difluorovinyllithium, generated from commercially available 1,1,1-trifluoro-2-iodoethane.
Transition metal-catalyzed nucleophilic addition of heteroatom nucleophiles to 1,1-difluoroallenes has been demonstrated here for the first time. Treatment of 1,1-difluoroallenes with O-nucleophiles, such as phenols, carboxylic acids, and sulfonic acids, facilitated unprecedented α-selective addition in the presence of AuCl3 or AuCl(PPh3)/AgSbF6 catalysts which afforded 1,1-difluoroallyl alcohol derivatives