NOVEL REACTIONS OF PHOSPHONIUM YLIDES WITH PERHALOALKANES: FIRST EXAMPLES OF HALOPHILIC ATTACKS BY PHOSPHONIUM YLIDES AND A FACILE ROUTE TO α-HALOALKYLPHOSPHONIUM SALTS

Article abstract of DOI:10.1016/S0040-4039(01)91362-0

Phosphonium ylides Ph₃=CHR (R = H, CH₃, C₂H₅, n-C₃H₇, n-C₅H₁₁) react readily with perhalofluoroalkanes to afford regiospecifically α-haloalkylphosphonium salts Ph₃P⁺-CHXR Y^- (X = I, Br, Cl) in good yields.These reactions reveal a new type of reactivity phosphonium ylides, i.e., the halophilic attack on C-X bonds, and may be useful for the regiospecific synthesis of substituted haloolefins via Wittig reaction.