title: Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine.
abstract: BACKGROUND
  1,1-Difluoroalkenes cannot only be used as valuable precursors for organic synthesis, but also act as bioisosteres for enzyme inhibitors. Among various methods for their preparation, the carbonyl olefination with difluoromethylene phosphonium ylide represents one of the most straightforward methods.
  
  
  RESULTS
  The combination of (chlorodifluoromethyl)trimethylsilane (TMSCF2Cl) and triphenylphosphine (PPh3) can be used for the synthesis of gem-difluoroolefins from carbonyl compounds. Comparative experiments demonstrate that TMSCF2Cl is superior to (bromodifluoromethyl)trimethylsilane (TMSCF2Br) and (trifluoromethyl)trimethylsilane (TMSCF3) in this reaction.
  
  
  CONCLUSIONS
  Similar to many other Wittig-type gem-difluoroolefination reactions in the presence of PPh3, the reaction of TMSCF2Cl with aldehydes and activated ketones is effective.
authors.affiliation: Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.affiliation: Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China.
authors.forename: Lingchun
authors.initials: L
authors.lastname: Li
authors.affiliation: Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China.
authors.forename: Chuanfa
authors.initials: C
authors.lastname: Ni
authors.affiliation: Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China.
authors.forename: Jinbo
authors.initials: J
authors.lastname: Hu
keywords: (chlorodifluoromethyl)trimethylsilane; Wittig reaction; difluorocarbene; gem-difluoroolefin; organo-fluorine; ylide