title: Photoredox-Catalyzed Reductive Dimerization of Isatins and Isatin-Derived Ketimines: Diastereoselective Construction of 3,3'-Disubstituted Bisoxindoles.
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.
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P. R. China.
authors.forename: Chao-Ming
authors.initials: CM
authors.lastname: Wang
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P. R. China.
authors.forename: Peng-Ju
authors.initials: PJ
authors.lastname: Xia
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P. R. China.
authors.forename: Jun-An
authors.initials: JA
authors.lastname: Xiao
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P. R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P. R. China.
authors.forename: Hao-Yue
authors.initials: HY
authors.lastname: Xiang
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P. R. China.
authors.forename: Xiao-Qing
authors.initials: XQ
authors.lastname: Chen
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University , Changsha 410083, P. R. China.
authors.forename: Hua
authors.identifier: 0000-0002-7404-4247
authors.initials: H
authors.lastname: Yang