Deprotonation/substitution reactions and polymerization of N-silylphosphoranimines

Abstract

A broad range of functionalized phosphoranimines have been synthesized by reacting the N-silylphosphoranimine anion 2 (eq 1) with various electrophiles. In previous work, the anion 2 had been shown to react with phosphorus and silicon halides (e.g., Ph$\sb2$PCl and RMe$\sb2$SiCl, where R = Me, Ph, CH=CH$\sb2$, H, (CH$\sb2)\sb3$C$\equiv$N) to give high yields of the expected products. This study initially involved reactions of the anion 2 with carbonyl compounds in an effort to determine if the anion would undergo reactions simliar to an organic alkyl lithium reagent. More importantly, this aspect of the study served as a useful model for the analogous chemistry of the poly(phosphazene) backbone. The major part of this work involved Peterson olefination reactions of the silylated derivative 3 (eq 2) of the anion 2. Deprotonation of 3 followed by addition of various aldehydes and ketones results in the formation of a large series of vinyl substituted N-silylphosphoraminines 4 (eq 2). The thermolysis reactions of these vinyl substituted N-silylphosphoranimines 4 were also studied. Several of these compounds were found to undergo condensation polymerization to yield soluble, linear copolymers (e.g., 5) with pendant vinyl substituents.