title: Catalytic enantioselective cascade Michael/cyclization reaction of 3-isothiocyanato oxindoles with exocyclic α,β-unsaturated ketones en route to 3,2'-pyrrolidinyl bispirooxindoles.
abstract: Cascade Michael/cyclization reactions between 3-isothiocyanato oxindoles and exocyclic α,β-unsaturated ketones are shown to proceed efficiently in the presence of a quinine-derived tertiary amino-squaramide catalyst and furnish 3,2'-pyrrolidinyl bispirooxindoles containing two spiro-quaternary and three contiguous stereocenters as a single diastereomer with excellent enantioselectivities (up to 99 : 1 er).
authors.affiliation: Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, India. sm@orgchem.iisc.ernet.in.
authors.forename: Satavisha
authors.initials: S
authors.lastname: Kayal
authors.affiliation: Department of Organic Chemistry, Indian Institute of Science, Bangalore 560 012, India. sm@orgchem.iisc.ernet.in.
authors.forename: Santanu
authors.identifier: http://orcid.org/0000-0001-9651-6228
authors.initials: S
authors.lastname: Mukherjee