Solvent-free zinc-catalysed hydroboration of esters

Abstract

This study presents the synthesis of a novel hemilabile bidentate amido phosphine sulfide III-10 ligand and introduces a new synthetic route to the previously reported amido/phosphine III- 12 and amido phosphine oxide III-11 analogues. The present study outlines the synthesis, isolation and characterization of zincII methyl complexes III-13 and III-14 supported by III-10 and III-12, respectively. The catalytic applications of these complexes in the hydroboration of several organic substrates, including esters, nitriles, and quinoline, have been documented. When esters were subjected to the reaction conditions involving III-14 and HBcat, it was shown that ZnMe2 is formed in situ. It was then established that ZnMe2 was an active catalyst for efficient reduction of esters, resulting in moderate to good yields.