Photoredox-Catalyzed Reductive Dimerization of Isatins and Isatin-Derived Ketimines: Diastereoselective Construction of 3,3'-Disubstituted Bisoxindoles

J Org Chem. 2017 Apr 7;82(7):3895-3900. doi: 10.1021/acs.joc.6b03056. Epub 2017 Mar 28.

Abstract

Reductive dimerization of isatin and its derivatives can be regarded as a step-economical pathway to construct 3,3'-disubstituted bisoxindoles, which was unfortunately accompanied by severe direct reduction as well as low efficiency. A visible-light driven, photoredox-catalytic protocol was developed to readily furnish 3,3'-dihydroxy- (dl-, > 20:1 dr) and 3,3'-diamino-bisoxindoles (meso-, 3.5:1 to 5:1 dr) in moderate to good yields, successfully circumventing the common problem. Two vicinal quaternary carbon centers were effectively assembled under the irradiation of visible light.

Publication types

  • Research Support, Non-U.S. Gov't