Reactivities of a 6-Carbaphosphatrane and Its Tautomer under Equilibrium

Abstract

We have already reported the syntheses and structures of 6-carbaphosphatrane 1 and its tautomer 2. We report here the reactivities of 1,2 as well as those of 5-carbaphosphatrane 5. The apical hydrogen atom of 1 was replaced by a deuterium atom by the reaction of 1,2 with methanol-d₁. This reaction proceeds through a proton exchange of 2. Treatment of 1,2 with Ph₃CClO₄ afforded a phosphonium cation 3 which was generated by a hydride abstraction from 1. Such reactivities are caused by changing of the property of the hydrogen atom of 1 and 2 via the tautomerization. Photoreaction of 1,2 with catalytic amount of PhSSPh afforded phosphonate 6 bearing a toluene moiety. We also investigated various radical reactions and these reaction mechanisms will also be described.