title: Organocatalyzed enantioselective Michael addition/cyclization cascade reaction of 3-isothiocyanato oxindoles with arylidene malonates.
abstract: An organocatalyzed Michael addition-cyclization reaction between 3-isothiocyanatooxindoles and arylidene malonates has been developed for the synthesis of highly functionalized 3,2'-pyrrolidinyl spirooxindole derivatives. The reaction was catalyzed by a quinine derived tertiary amino-thiourea based bifunctional catalyst or its pseudo-enantiomeric quinidine derived catalyst providing both the enantiomers of the desired product. The products were obtained in high yields and with excellent diastereo- (up to 99 : 1 dr) and enantioselectivities (up to >99% ee).
authors.affiliation: Bio-Organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India. raghuc@barc.gov.in.
authors.forename: Raghunath
authors.initials: R
authors.lastname: Chowdhury
authors.affiliation: Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Kumar
authors.affiliation: Bio-Organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India. raghuc@barc.gov.in.
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Ghosh