Enantioselective hydrogenation of [alpha]-aryloxy and [alpha]-alkoxy [alpha],[beta]-unsaturated carboxylic acids catalyzed by chiral spiro iridium/phosphino-oxazoline complexes

The mechanisms involved in the iridium-catalyzed highly enantioselective hydrogenation of [alpha]-aryloxy and [alpha]-alkoxy [alpha],[beta]-unsaturated carboxylic acids are explained. The catalyst is shown to lead to an excellent chiral discrimination because of the presence of a completely hindered chiral environment.