Release Time:2019-03-11  Hits:

Indexed by: Journal Article

Date of Publication: 2018-02-07

Journal: ORGANIC & BIOMOLECULAR CHEMISTRY

Included Journals: PubMed、EI、SCIE

Volume: 16

Issue: 5

Page Number: 807-815

ISSN: 1477-0520

Abstract: 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.