Cheng T1, Ye Q1, Zhao Q1, Liu G1.
Org Lett. 2015 Oct 16;17(20):4972-5. doi: 10.1021/acs.orglett.5b02394. Epub 2015 Oct 6.Dynamic kinetic resolution of phthalides through asymmetric transfer hydrogenation for the construction of 3-(2-hydroxy-2-arylethyl)isobenzofuran-1(3H)-one with 1,3-distereocenters has been developed. This procedure is carried out under a mild condition at 40 °C catalyzed with RuCl[(S,S)-TsDPEN](mesitylene) using HCOOH/Et3N (5:2) as a hydrogen source. A variety of phthalides are smoothly transferred to provide optically pure phthalides with high yields, excellent enantioselectivities, and acceptable diastereomeric ratios.