Enantioconvergent Synthesis of (+)-Aphanorphine via Asymmetric Pd-Catalyzed Alkene Carboamination

摘要

A concise asymmetric synthesis of (+)-aphanorphine has been achieved via a new enantioconvergent strategy. A racemic γ-aminoalkene derivative is transformed into a 1:1 mixture of enantiomerically enriched diastereomers using an asymmetric Pd-catalyzed carboamination. This mixture is then converted to an enantiomerically enriched protected aphanorphine derivative by a Friedel-Crafts reaction, which generates a quaternary all-carbon stereocenter. The natural product is obtained in three additional steps.