title: N-Heterocyclic carbene-catalyzed enantioselective annulations: a dual activation strategy for a formal [4+2] addition for dihydrocoumarins.
abstract: A highly efficient asymmetric formal [4+2] annulation for the synthesis of dihydrocoumarins has been developed via an in situ activated NHC catalysis. Both electrophilic and nucleophilic species are generated in situ simultaneously whereby acyl imidazoles facilitated rapid formation of an NHC-enolate intermediate to afford the [4+2] dihydrocoumarin adducts.
authors.affiliation: Department of Chemistry, Center for Molecular Innovation and Drug Discovery, Chemistry of Life Processes Institute, Northwestern University, Silverman Hall, Evanston, Illinois 60208, USA. scheidt@northwestern.edu.
authors.forename: Anna
authors.initials: A
authors.lastname: Lee
authors.forename: Karl A
authors.initials: KA
authors.lastname: Scheidt
mesh_terms: D002384:Catalysis; D003374:Coumarins / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D003374:Coumarins; D006571:Heterocyclic Compounds; C030011:carbene; D008697:Methane