Conversion of phosphinic into phosphinous esters through nickelocene reduction–complexation of phosphinothioic O-esters. A new synthesis of carbon–phosphorus heterocycles

A new procedure for reducing a phosphinate (LO) into the corresponding phosphinite (L) includes the following steps: LO → LS → CpNi(I)L → NiL4→ L (Cp = cyclopentadiene); such a scheme is illustrated by the syntheses of 2-phenyl-1,2-oxaphospholane and 2-phenylisophosphindoline 2-oxide.