title: Stereoselective synthesis of isoquinuclidines through an aza-[4 + 2] cycloaddition of chiral cyclic 2-amidodienes.
abstract: A highly stereoselective aza-[4 + 2] cycloaddition of chiral cyclic 2-amidodienes with N-sulfonyl aldimines is described. While this Lewis acid promoted heterocycloaddition provides an efficient strategy for constructing optically enriched isoquinuclidines, it is mechanistically intriguing. The cycloaddition favored the endo-II pathway in the absence of a viable bidentate coordination. This represents an unexpected switch from the anticipated endo-I selectivity obtained in the all-carbon cycloaddition.
authors.affiliation: Division of Pharmaceutical Sciences, School of Pharmacy, University of Wisconsin , Madison, Wisconsin 53705, United States.
authors.forename: Li-Chao
authors.initials: LC
authors.lastname: Fang
authors.forename: Richard P
authors.initials: RP
authors.lastname: Hsung
mesh_terms: D000466:Alkadienes / Q000737:chemistry; D001372:Aza Compounds / Q000737:chemistry*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D061565:Cycloaddition Reaction; D058116:Lewis Acids / Q000737:chemistry; D015394:Molecular Structure; D011812:Quinuclidines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000466:Alkadienes; D001372:Aza Compounds; D058116:Lewis Acids; D011812:Quinuclidines