Enantioselective hydrogenation of enol esters in water.

Abstract

Significant work has been done using traditional organic solvents for catalytic asymmetric hydrogenations. Recently, there have also been reports of the successful use of alternative reaction media such as ionic liquids and water as the sole reaction solvent in the catalytic asymmetric hydrogenation of α-benzamido acrylate esters. Building off of these reports, this work looks at the plausibility of utilizing water as the sole reaction solvent in the catalytic asymmetric hydrogenation of enol ester substrates. In particular, this study employed the use of the chiral EtDuPHOS and CatASium catalysts as well as the achiral DiPFc catalyst. While the enol ester substrates, specifically the benzoates, employed in the hydrogenation reactions were successfully synthesized, the catalytic asymmetric hydrogenations in water did not yield the desired α-hydroxy acid products.