Reactive FLP–alkyne addition products: a route to anionic and zwitterionic phosphines

Abstract

Combination of a phosphinidene precursor, B(C₆F₅)₃ and 4-ethynyltoluene afforded the FLP addition product, Et₂N(C₁₄H₁₀)PC(Tol)CH (B(C₆F₅)₃) 2. Compound 2 reacted with halides, pseudo-halides or Me₃SiSPh to provide a facile route to the salts of anionic phosphines while reaction with PEt₃ gave the zwitterion Et₃PCHC(SiMe₃)P(NEt₂)C(Tol)CHB(C₆F₅)₃8. This latter species reacted with an alkyne to give a phosphine donor with both olefin-linked cationic and anionic substituents.