Ruthenium-Catalyzed Synthesis of cis-2,3-Dihydrobenzofuran-3-ols by Aqueous Transfer Hydrogenation via Dynamic Kinetic Resolution

The preparation of cis-2,3-dihydrobenzofuranols with two stereocenters through aqueous asymmetric transfer hydrogenation (ATH) of benzofuranones with the metal catalyst Ru­(II) via dynamic kinetic resolution (DKR) has been developed. A variety of α-alkyl benzofuranones were transformed to obtain optically pure 2,3-dihydrobenzofuran-3-ols with excellent enantioselectivities and acceptable yields under mild conditions.