Highly Enantioselective Organocatalytic Formation of Functionalized Cyclopentane Derivatives via Tandem Conjugate Addition/α-Alkylation of Enals
作者:Marek Remeš、Jan Veselý
DOI:10.1002/ejoc.201200334
日期:2012.7
An enantioselective tandem reaction between dialkyl 2-haloethylmalonates and aromatic enals catalyzed by secondary amine catalysts is described. The reaction proceeds through a Michael/α-alkylation reaction sequence to afford the final 1,1,2,3-tetrasubstituted cyclopentanes in good yields (up to 75 %) with high diastereoselectivity and enantioselectivity (up to 20:1 dr and 93 % ee). Moreover, the
描述了由仲胺催化剂催化的 2-卤乙基丙二酸二烷基酯和芳族烯醛之间的对映选择性串联反应。该反应通过迈克尔/α-烷基化反应序列进行,以良好的产率(高达 75 %)、高非对映选择性和对映选择性(高达 20:1 dr 和 93 %)提供最终的 1,1,2,3-四取代环戊烷ee)。此外,迈克尔/α-烷基化反应也在低催化剂负载量(5 mol%)下进行,对选择性的影响很小,没有观察到 O-和 N-烷基化产物。