The readily available (+)-N-Benzyl-(S)-mandelamide catalyzes the enantioselective addition of dimethylzinc to α-keto esters to give α-methyl-α-hydroxy esters containing stereogenic quaternary centers with moderate to good yields (56-87%). A good enantioselectivity of the reaction is obtained for aryl and heteroaryl keto esters. For these substrates ee values of 75-90% are obtained. The enantioselectivity
容易获得的 (+)-N-苄基-(S)-扁桃酰胺催化二甲基
锌与 α-
酮酯的对映选择性加成,得到含有立体季
铵中心的 α-甲基-α-羟基酯,产率适中至高 (56-87 %)。对于芳基和杂芳基
酮酯,反应具有良好的对映选择性。对于这些基材,获得了 75-90% 的 ee 值。对于带有脂肪链的底物,对映选择性稍低。