title: Controlling Asymmetric Remote and Cascade 1,3-Dipolar Cycloaddition Reactions by Organocatalysis.
abstract: The regio- and stereoselective control of cycloaddition reactions to polyconjugated systems has been demonstrated by applying asymmetric organocatalysis. Reaction of 2,4-dienals with nitrones allows for a highly regio- and stereoselective 1,3-dipolar cycloaddition in the presence of an aminocatalyst. The first cycloaddition on the remote olefin can be followed either by a cascade reaction or by other selective reactions of the remaining olefin. The chiral products are obtained in good to high yields and excellent diastereo- and enantioselectivities. The remote selective concept has been extended to 2,4,6-trienals by means of a novel enantioselective triple cascade 1,3-dipolar cycloaddition reaction. The formation of chiral poly 1,3-amino alcohols is also demonstrated.
authors.affiliation: Department of Chemistry, Aarhus University , DK-8000 Aarhus C, Denmark.
authors.forename: Pernille H
authors.initials: PH
authors.lastname: Poulsen
authors.affiliation: Department of Chemistry, Aarhus University , DK-8000 Aarhus C, Denmark.
authors.forename: Stefania
authors.initials: S
authors.lastname: Vergura
authors.affiliation: Department of Chemistry, Aarhus University , DK-8000 Aarhus C, Denmark.
authors.forename: Alicia
authors.initials: A
authors.lastname: Monleón
authors.affiliation: Department of Chemistry, Aarhus University , DK-8000 Aarhus C, Denmark.
authors.forename: Danny Kaare Bech
authors.initials: DK
authors.lastname: Jørgensen
authors.affiliation: Department of Chemistry, Aarhus University , DK-8000 Aarhus C, Denmark.
authors.forename: Karl Anker
authors.initials: KA
authors.lastname: Jørgensen