title: An N-heterocyclic carbene/Lewis acid strategy for the stereoselective synthesis of spirooxindole lactones.
abstract: A cooperative catalysis approach for the enantioselective formal [3+2] addition of α,β-unsaturated aldehydes to isatins has been developed. Homoenolate annulations of β-aryl enals catalyzed by an N-heterocyclic carbene (NHC) require the addition of lithium chloride for high levels of enantioselectivity. This NHC-catalyzed annulation has been used for the total synthesis of maremycin B.
authors.affiliation: Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA.
authors.forename: Julien
authors.initials: J
authors.lastname: Dugal-Tessier
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: O'Bryan
authors.forename: Thomas B H
authors.initials: TB
authors.lastname: Schroeder
authors.forename: Daniel T
authors.initials: DT
authors.lastname: Cohen
authors.forename: Karl A
authors.initials: KA
authors.lastname: Scheidt
mesh_terms: D002384:Catalysis; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D058116:Lewis Acids / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives / Q000737:chemistry; D015394:Molecular Structure; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D007211:Indoles; D007783:Lactones; D058116:Lewis Acids; D013141:Spiro Compounds; C030011:carbene; D008697:Methane