title: Enantioselective [2+2] annulation of simple aldehydes with isatin-derived ketimines via oxidative N-heterocyclic carbene catalysis.
abstract: An asymmetric [2+2] annulation reaction through direct α-carbon functionalization of simple aldehydes via oxidative N-heterocyclic carbene catalysis is disclosed. These in situ generated triazolium enolate intermediates undergo a highly stereoselective Mannich reaction with isatin-derived ketimines followed by intramolecular lactamization to afford enantioenriched spirooxindole β-lactams bearing two vicinal stereogenic centers.
authors.affiliation: Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, People's Republic of China. jfxu@zstu.edu.cn renhj@zstu.edu.cn.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Xu
authors.forename: Shiru
authors.initials: S
authors.lastname: Yuan
authors.forename: Jingyi
authors.initials: J
authors.lastname: Peng
authors.forename: Maozhong
authors.initials: M
authors.lastname: Miao
authors.forename: Zhengkai
authors.initials: Z
authors.lastname: Chen
authors.forename: Hongjun
authors.initials: H
authors.lastname: Ren