Yanbian University, Yanji 133000, China）РР Abstract: Takemoto′s（ thio）urea derivatives were applied in the asymmetric direct Aldol reaction of isatins and acet- Р oacetate. Under the condition of 0.1 mmol substrate amount, the optimized conditions were determined to be 5%（Mole Р fraction） loading catalyst N［- 3,5-Bis（trifluoromethyl）phenyl］ -N′［（- 1S, 2S）-2（- dimethylamino）cyclohexyl］urea（ 1b） Р in methyl tert-butyl ether（ 1 mL） at 0 ℃ . The different substituted isatins were evaluated for the generality of this Р reaction, the desired chiral δ（- 2- oxindole-3yl-）-δ-hydroxy-β-ketoesters bearing the were obtained in 76%~87% Р yield with up to 87% enantiomeric excess（ ee ）. Р Key words： Takemoto′s（ thio）urea derivatives; asymmetric direct Aldol reaction; isatins; acetoacetates
全文预览
