title: Asymmetric triple relay catalysis: enantioselective synthesis of spirocyclic indolines through a one-pot process featuring an asymmetric 6π electrocyclization.
abstract: A rare example of a one-pot process that involves asymmetric triple relay catalysis is reported. The key step is an asymmetric [1,5] electrocyclic reaction of functionalized ketimines. The substrates for this process were obtained in situ in a two-step process that involved the hydrogenation of nitroarenes with a Pd/C catalyst to yield aryl amines and their subsequent coupling with isatin derivatives in a Brønsted acid catalyzed ketimine formation reaction. The electrocyclization was catalyzed by a bifunctional chiral Brønsted base/hydrogen bond donor catalyst. The one-pot process gave the desired products in good yields and with excellent enantioselectivity.
authors.affiliation: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663N, Zhongshan Road, Shanghai 200062 (China).
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Yin
authors.forename: Xing-Ping
authors.initials: XP
authors.lastname: Zeng
authors.forename: Yun-Lin
authors.initials: YL
authors.lastname: Liu
authors.forename: Fu-Min
authors.initials: FM
authors.lastname: Liao
authors.forename: Jin-Sheng
authors.initials: JS
authors.lastname: Yu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
keywords: asymmetric catalysis; electrocyclic reactions; one-pot processes; tandem reaction; thioureas