title: Asymmetric organocatalytic epoxidation of alpha,beta-unsaturated aldehydes with hydrogen peroxide.
abstract: The first asymmetric organocatalytic epoxidation of alpha,beta-unsaturated aldehydes is presented. A chiral bisaryl-silyl-protected pyrrolidine acts as a very selective epoxidation organocatalyst using simple oxidation agents, such as hydrogen peroxide and tert-butyl hydroperoxide. The asymmetric epoxidation reactions proceed under environmental friendly reaction condition in, for example, water mixtures of alcohols, and the scope of the reaction is demonstrated by the formation of optically active alpha,beta-epoxy aldehydes in high yields and enantioselectivities >94% ee. Furthermore, the direct synthesis of the sex pheromone from an acaric mite by asymmetric epoxidation of citral is presented.
authors.affiliation: Danish National Research Foundation, Center for Catalysis, Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Mauro
authors.initials: M
authors.lastname: Marigo
authors.forename: Johan
authors.initials: J
authors.lastname: Franzén
authors.forename: Thomas B
authors.initials: TB
authors.lastname: Poulsen
authors.forename: Wei
authors.initials: W
authors.lastname: Zhuang
authors.forename: Karl Anker
authors.initials: KA
authors.lastname: Jørgensen