title: Asymmetric Kinugasa reaction of cyclic nitrones and nonracemic acetylenes.
abstract: Kinugasa reactions between chiral acetylenes and five-membered nitrones, achiral and bearing a stereogenic center in both enantiomeric forms, proceed in moderate to good yield with high diastereoselectivity affording mostly one dominant product. The first step of the reaction is controlled by the configuration of the nitrone, whereas the protonation of intermediate enolate in the second step depends mainly on the configuration of the bridgehead carbon atom formed in the first step. In the case of the mismatched pair, the configuration at the C-6 center of the carbapenam skeleton may also be affected by the configuration of the stereogenic center in the acetylene portion.
authors.affiliation: Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Stecko
authors.forename: Adam
authors.initials: A
authors.lastname: Mames
authors.forename: Bartlomiej
authors.initials: B
authors.lastname: Furman
authors.forename: Marek
authors.initials: M
authors.lastname: Chmielewski