title: Conversion between difluorocarbene and difluoromethylene ylide.
abstract: The interconversion between difluoromethylene ylide and difluorocarbene is described. The difluoromethylene ylide precursor, Ph3P(+)CF2CO2(-), could be turned into an efficient difluorocarbene reagent, whereas the classical difluorocarbene reagents, HCF2Cl and FSO2CF2CO2TMS, could generate highly reactive difluoromethylene ylide. Thus the Wittig difluoro-olefination and difluorocyclopropanation could be selectively realized by using the same reagent. In addition, the ylides obtained from different carbene sources showed different reactivity in Wittig reactions.
authors.affiliation: Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032 (P.R. China), Fax: (+86) 21-6416-6128.
authors.forename: Jian
authors.initials: J
authors.lastname: Zheng
authors.forename: Jin-Hong
authors.initials: JH
authors.lastname: Lin
authors.forename: Ji
authors.initials: J
authors.lastname: Cai
authors.forename: Ji-Chang
authors.initials: JC
authors.lastname: Xiao
keywords: carbenes; difluoro-olefination; difluorocyclopropanation; fluorine; ylides