Enantioselective Synthesis of Chiral Dihydroisobenzofurans via Tandem Asymmetric Hydrogenation and Selective Oxo-cyclization.

We report a practical one-pot protocol for accessing chiral dihydroisobenzofurans via tandem asymmetric hydrogenation and selective 5-exo-dig oxo-cyclization. This method displays high activity (up to 99% yield and S/C = 2000:1) and excellent selectivity (up to 99% ee and exclusive Z selectivity) across a broad substrate scope. Scale-up reactions and further transformations afforded challenging derivatives bearing cis-1,3-stereogenic centers. The operational simplicity and high efficiency arise from the synergistic dual roles of the metal and base.