Enantioselective synthesis of trifluoromethyl substituted piperidines with multiple stereogenic centers via hydrogenation of pyridinium hydrochlorides†
Abstract
An enantioselective iridium-catalyzed hydrogenation of trifluoromethyl substituted pyridinium hydrochlorides is described. Introduction of a trifluoromethyl group increases the reactivity due to the electron-withdrawing effect. Three stereogenic centers could be generated in one operation. This methodology provides a convenient route to chiral poly-substituted piperidines with up to 90% ee.