title: A cooperative N-heterocyclic carbene/chiral phosphate catalysis system for allenolate annulations.
abstract: The highly enantioselective NHC-catalyzed [3+2] annulation reaction with α,β-alkynals and α-ketoesters has been developed. A new mode of cooperative catalysis involving the combination of a chiral Brønsted acid and a C1-symmetric biaryl saturated-imidazolium precatalyst was required to generate the desired γ-crotonolactones in high yields and levels of enantioselectivity.
authors.affiliation: Department of Chemistry Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (USA).
authors.forename: Anna
authors.initials: A
authors.lastname: Lee
authors.forename: Karl A
authors.initials: KA
authors.lastname: Scheidt
mesh_terms: D002384:Catalysis; D006571:Heterocyclic Compounds / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D006571:Heterocyclic Compounds; D010710:Phosphates; C030011:carbene; D008697:Methane
keywords: N-heterocyclic carbene; annulation; asymmetric synthesis; cooperative catalysis; synthetic methods