title: A Catalyst-Enabled Diastereodivergent Aza-Diels-Alder Reaction: Complementarity of N-Heterocyclic Carbenes and Chiral Amines.
abstract: Highly efficient and diastereodivergent aza-Diels-Alder reactions have been developed to access either diastereomeric series of benzofuran-fused δ-lactams and dihydropyridines in nearly perfect stereoselectivity (d.r. >20:1, >99 % ee for all examples). The complementarity of N-heterocyclic carbene and chiral amine as the catalyst was demonstrated for the first time, together with an excellent level of catalytic efficiency (1 mol % loading).
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543.
authors.forename: Zi-Qiang
authors.initials: ZQ
authors.lastname: Rong
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543.
authors.forename: Chi Hao Eugene
authors.initials: CH
authors.lastname: Chow
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543. zhaoyu@nus.edu.sg.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhao
keywords: Diels-Alder cycloaddition; N-heterocyclic carbenes; chiral amines; diastereodivergence; enantioselectivity