Ir-SpinPHOX Catalyzed Enantioselective Hydrogenation of 3-Ylidenephthalides

摘要

The first asymmetric hydrogenation of 3-ylidenephthalides has been developed using the Ir-I complex of a spiro-[4,4]-1,6-nonadiene-based phosphine-oxazoline ligand (Spin-PHOX) as the catalyst, affording a wide variety of chiral 3-substituted phthalides in excellent enantiomeric excesses (up to 98% ee). The utility of the protocol has been demonstrated in the asymmetric synthesis of chiral drugs NBP and BZP precursor, as well as the natural products chuangxinol and typhaphthalide.