Synthesis of 3-stannyl and 3-silyl propargyl phosphanes and the formation of a phosphinoallene

Abstract

The group 14 chloropropargyls R₃ECCCH₂Cl (R₃E = ⁿBu₃Sn, Ph₃Sn, Me₂PhSi, ⁱPr₃Si, ⁿPr₃Si, ⁿBu₃Si), obtained by a modified literature procedure, react with LiPPh₂ to afford the novel propargyl phosphanes Ph₂PCH₂CCER₃ in high yield, as viscous oils; (Me₃Si)₂PCH₂CCSiPhMe₂ is similarly obtained from LiP(SiMe₃)₂. In contrast, the reaction of PhCCCH₂MgCl with ClP(NEt₂)₂ fails to produce a comparable propargyl phosphane, but generates preferentially (>70%) the novel phosphinoallene (Et₂N)₂PC(Ph)CCH₂, which is characterised spectroscopically, and through its reaction with HCl. The coordination chemistry of representative phosphanes is explored with respect to platinum and palladium for the first time.