Diastereodivergent asymmetric Michael-alkylation reactions using chiral<i>N</i>,<i>N</i>′-dioxide/metal complexes
作者:Yulong Kuang、Bin Shen、Li Dai、Qian Yao、Xiaohua Liu、Lili Lin、Xiaoming Feng
DOI:10.1039/c7sc02757e
日期:——
A diastereodivergent asymmetric Michael-alkylation reaction between 3-chloro-oxindoles and β,γ-unsaturated-α-ketoesters has been achieved using L-RaPr2/Sc(OTf)3 and L-PrPr2/Mg(OTf)2 metal complexes as catalysts. Both rel-(1R,2S,3R) and rel-(1S,2S,3R) chiral spiro cyclopropane oxindoles were constructed in good yields, diastereoselectivities and ee values. The diastereodivergent control may originate
使用L-RaPr 2 / Sc(OTf)3和L-PrPr 2 / Mg(OTf)2金属配合物实现了3-氯-氧吲哚与β,γ-不饱和α-酮酸酯之间的非对映异构性不对称Michael-烷基化反应作为催化剂。两个相对- (1 - [R,2小号,3 - [R )和相对- (1小号,2小号,3 - [R)手性螺环丙烷氧吲哚的收率,非对映选择性和ee值均良好。非对映异构控制可能来自迈克尔加成后的不同烷基化途径,可能是氮杂-邻二甲苯基中间体的分子内捕集或直接的S N 2取代。