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 catalytic asymmetric 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
描述了乙烯酮二硫缩醛的前所未有的催化不对称质子化。在手性布朗斯台德酸催化剂的存在下,各种外消旋 α-芳基氢化香豆素衍生物转化为对映体富集的二硫代缩醛保护的氢化香豆素。引入了一种新开发的磷酸,具有 3,5-双 (五氟硫代) 苯基 (3,5-(SF(5))(2)C(6)H(3)) 取代基。所得产物可以分别通过简单的水解或氢化容易地转化为氢化香豆素或相应的色满。