Synthesis of free and ligated 1,2-thiaphosphetanes - expanding the pool of strained P-ligands.

Abstract

While P(v) 1,2-oxaphosphetanes were investigated in great detail over the past decades, the knowledge about P(v) 1,2-thiaphosphetanes is rather scarce, and P(iii) derivatives are unknown. Herein, we present the synthesis of the first P(iii) complex derivatives formed in the coordination sphere of group 6 metals and, additionally, the first unligated P(iii) 1,2-thiaphosphetanes. The latter display an unusually low HOMO-LUMO gap thus constituting excellent candidates for redox-cycling organocatalysts.