Asymmetric Organocatalytic Cascade Synthesis of Tetrahydrofuranyl SpirooxindolesThe authors thank the Estonian Ministry of Education and Research (grant nos. IUT19-32, IUT19-9, IUT23-7, PUT1468 and PUT692) and the Centre of Excellence in Molecular Cell Engineering (2014-2020.4.01.15-0013) for financial support.
Received: 20 July 2017
Accepted after revision: 05 September 2017
18 September 2017 (eFirst)
Dedicated to Professor Victor Snieckus on the occasion of his 80th birthday
An enantio- and regioselective organocatalytic cascade starting from isatin has been disclosed to construct tetrahydrofuranyl spirooxindoles in high yields and stereoselectivities. Also, a triple cascade leading to the pentacyclic compound with two quaternary and a tertiary stereocenter is described. The reactions were catalyzed by cinchonine-based thiourea.