Diastereoselectivity and enantioselectivity in the addition of chiral imines of 2-methylcyclohexanone to crotonic and methacrylic acid esters
作者:Ivan Jabin、Gilbert Revial、Alain Tomas、Pascale Lemoine、Michel Pfau
DOI:10.1016/0957-4166(95)00226-f
日期:1995.7
established that the reactants complex has a chairlike geometry. In all the examples, the diastereoselectivity is superior to 98%. The enantioselectivity of the reactions is excellent as is usually the case with unsubstituted electrophilic olefins, the example with phenyl methacrylate being particularly remarkable (de and ee >99%). In each case the favored diastereofacial selectivity is again in accordance
由(S)-1-苯基乙胺和2-甲基环己酮获得的手性亚胺(作为其仲烯胺互变异构体)的添加与巴豆酸和甲基丙烯酸的苯基酯以及它们的甲酯一起进行。在每个实施例中,主要加合物中取代基的立体化学关系显示为先前的理论计算中所预测的关系,该理论确定了反应物配合物具有椅状几何形状。在所有实施例中,非对映选择性均优于98%。反应的对映选择性极好,这通常是未取代的亲电烯烃所致,甲基丙烯酸苯酯的实例尤为显着(de和ee> 99%)。在每种情况下,有利的非对面选择性都再次符合先前阐述的规则。给出了有关取代基对反应性,区域异构体的比例,立体选择性和对映选择性的影响的有关事实。