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论文类型：期刊论文

发表时间：2018-02-07

发表刊物：ORGANIC & BIOMOLECULAR CHEMISTRY

收录刊物：SCIE、EI、PubMed

卷号：16

期号：5

页面范围：807-815

ISSN号：1477-0520

摘要：An organocatalytic asymmetric [3 + 2] cycloaddition of oxindole-based azomethine ylides with 3-nitro-2H-chromenes has been developed. This reaction provides a facile approach to densely functionalized polycyclic spirooxindole-chromane adducts featuring four contiguous stereogenic centers, including two tetrasubstituted carbon centers. The products were obtained in high yields with good to excellent stereoselectivities (up to 99% yields, 96% ee and >20 : 1 dr). In addition, the spiro[pyrrolidine-2,3'-oxindole]chromane adducts could be readily derivatized via simple oxidation and reduction treatment. A dual activation working model to illuminate the stereochemical course of the [3 + 2] cycloaddition event is proposed.