title: Highly stereoselective formal
abstract: [formula: see text] Highly stereoselective formal [3 + 3] cycloaddition reactions of chiral vinylogous amides with alpha, beta-unsaturated iminiums are described. A mechanistic model is proposed to rationalize the observed stereoselectivity. The 6 pi-electron electrocyclic ring closure appears to be reversible, and a preferred rotation of the alkenyl group, one of the three 2 pi-components, during the ring closure step provides the thermodynamically favored diastereomer as the major product.
authors.affiliation: Department of Chemistry, University of Minnesota, Minneapolis 55455, USA.
authors.initials: HM
authors.lastname: Sklenicka
authors.initials: RP
authors.lastname: Hsung
authors.initials: LL
authors.lastname: Wei
authors.initials: MJ
authors.lastname: McLaughlin
authors.initials: AI
authors.lastname: Gerasyuto
authors.initials: SJ
authors.lastname: Degen