Deracemization of α-Aryl Hydrocoumarins via Catalytic Asymmetric Protonation of Ketene Dithioacetals
作者:Ji-Woong Lee、Benjamin List
DOI:10.1021/ja3096202
日期:2012.11.7
An unprecedented catalyticasymmetric protonation of ketene dithioacetals is described. Various racemic α-aryl hydrocoumarin derivatives are transformed into enantioenriched dithioacetal-protected hydrocoumarins in the presence of a chiral Brønsted acid catalyst. A newly developed phosphoric acid, featuring the 3,5-bis(pentafluorothio)phenyl (3,5-(SF(5))(2)C(6)H(3)) substituent, is introduced. The