文献类型：期刊文献

英文题名：Chiral Br?nsted Base Activation of Donor-Acceptor Cyclopropanes toward Diastereo- and Enantioselective [3 + 2] Cycloaddition with Isatin-Derived Ketimines

作者：Yu, Zhe-Jia[1]; Yan, Shuang[1]; Zhao, Xiao-Li[2]; Zhang, Jun[1]; Zhao, Mei-Xin[1]

机构：[1] Key Laboratory for Advanced Materials and Institute of Fine Chemicals, School of Chemistry & Molecular Engineering, East China University of Science and Technology, 130 Mei Long Road, Shanghai, 200237, China; [2] Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai, 200062, China

年份：2024

卷号：89

期号：12

起止页码：8691

外文期刊名：Journal of Organic Chemistry

收录：EI(收录号：20242516273767)

语种：英文

外文关键词：Chemical activation - Cycloaddition - Ketones - Propane

摘要：Organocatalyzed diastereo- and enantioselective [3 + 2] cycloaddition reactions of donor-acceptor (D-A) cyclopropanes with isatin-derived ketimines are presented. Different from well-developed Lewis acid activation protocols which promote the reactivity of D-A cyclopropanes through coordinating to the acceptor group, in this reaction, dicyanocyclopropylmethyl ketones can be activated through nucleophilic activation of the donor group by using dihydroquinine-derived squaramide as Br?nsted base catalyst. The reaction affords functionalized spiro[oxindole-3,2′-pyrrolidines] with two nonadjacent tetra- and tri-substituted stereocenters in 83-99% yields, moderate to excellent diastereoselectivities (up to >20:1 diastereomeric ratio (dr)), and excellent enantioselectivities (up to >99% enantiomeric excess (ee)) under mild conditions. ? 2024 American Chemical Society.