ENANTIOSELECTIVE SYNTHESIS OF ASYMMETRIC BETA-CARBOLINE INTERMEDIATES

摘要

Described herein is a new asymmetric synthesis of imines to obtainβ-carboline derivatives useful as key intermediate compounds for the synthesis of phosphodiesterase inhibitors using a new process with palladium or ruthenium hydride and/or nickel boride to reduce chiral intermediates. The use of chloroformate chiral auxiliaries is further described for the reduction and asymmetric hydrogenation of imines to obtainβ-carboline derivatives and intermediate compounds used in the preparation thereof.