title: N-heterocyclic carbene and Brønsted acid cooperative catalysis: asymmetric synthesis of trans-γ-lactams.
abstract: An efficient enantioselective approach to form trans-γ-lactams in up to 99% yield, 93% ee, and >20/1 dr using unactivated imines has been developed. The cyclohexyl-substituted azolium and the weak base sodium o-chlorobenzoate are most suitable for this transformation. Notably, the process involves cooperative catalysis by an N-heterocyclic carbene and a Brønsted acid.
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States.
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Zhao
authors.forename: Daniel A
authors.initials: DA
authors.lastname: DiRocco
authors.forename: Tomislav
authors.initials: T
authors.lastname: Rovis
mesh_terms: D002384:Catalysis; D007097:Imines / Q000737:chemistry*; D007769:Lactams / Q000138:chemical synthesis* / Q000737:chemistry; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D007097:Imines; D007769:Lactams; C030011:carbene; D008697:Methane