The 1-Silyl-1H-phosphirene/1,2-Dihydrophosphasilete Rearrangement and Its Preparative Significance

Abstract

The 1H-phosphirene 1, which bears three trimethylsilyl groups at the P-silicon atom, undergoes isomerization under photolysis conditions by a previously unknown ring expansion with concomitant shift of a trimethylsilyl group to give the 1,2-dihydro-1,2-phosphasilete 2. After a silyl/acyl exchange at phosphorus, a further ring expansion by [1,3]-Si(Tms)2 shift furnishes the 6H-1,3,6-oxaphosphasilines (2→3).