The asymmetric direct aldol condensation of aldehydes with ethyl- and propylketones is catalyzed by syn-α-aminoalcoholâYb(OTf)3 complexes, yielding the anti-1,3-diol monoesters with high diastereocontrol and good enantioselectivity. Three adjacent stereogenic centers are created in a simultaneous aldol condensation and EvansâTishchenko reduction in an acyclic system.
醛与乙基和丙基酮的不对称直接Aldol缩合反应在syn-
α-氨基酸醇-Yb(OTf)3配合物的催化下进行,产生具有高立体控制性和良好对映选择性的anti-1,3
-二醇单酯。在非环状体系中,通过同时进行的Aldol缩合和Evans-Tishchenko还原反应,同时生成了三个相邻的手性中心。