二价过渡金属配合物催化的醇酮缩合

Aldol Condensation Catalyzed by the Transition Metal ( Ⅱ ) Coordination Compounds

以酸或碱催化的醇酮缩合反应,通常得到的是α,β-不饱和酮.Watanabe等人以对硝基苯甲醛与丙酮缩合为标准反应,研究了光学活性的L-酪氨酸乙酯-金属离子(主要是Zn2+离子)催化体系催化的醇酮缩合反应,得到有光学活性的β-醇酮产物。并初步研究了β-CD对该催化体系的协助效应。在L-酪氨酸-Zn2+-β-CD的催化下,水溶液中反应得到无光学活性的β-醇酮产物。

The aldol condensation of p- nitrobenzaldehyde with acetone catalyzed by metal ( Ⅱ )-ephedrine-BB-CD and metal ( Ⅱ )-N-methylephedrine-BB-CD systems was carried out under mild and neutral conditions to afford an enantiomorphous excess aldol type product, 4-hydroxy-4-(4-nitro-phenyl)-2-butanone. The highest yield of the aldol type product is 82. 8%. The highest specific rotation [aaaa]D15 is -6.7.