title: Highly selective palladium-catalyzed synthesis of protected alpha,beta-unsaturated methyl ketones and 2-alkoxy-1,3-butadienes. High-speed chemistry by microwave flash heating
abstract: A selective and mild procedure is described for the direct synthesis of 2-alkene-2-methyl-1,3-dioxolanes via regiocontrolled Heck vinylation of commercially available 2-hydroxyethyl vinyl ether. The procedure permits chemoselective transformation of a vinylic triflate or bromide into a blocked alpha,beta-unsaturated methyl ketone. Furthermore, a significantly improved and highly regioselective synthesis of 2-alkoxy-1,3-butadienes has been developed. Flash heating by microwave irradiation promotes the palladium-catalyzed reactions, and the starting materials are fully converted after reaction times of 5-7 min.
authors.affiliation: Department of Organic Pharmaceutical Chemistry, Uppsala Biomedical Centre, Uppsala University, Sweden.
authors.initials: KS
authors.lastname: Vallin
authors.initials: M
authors.lastname: Larhed
authors.initials: K
authors.lastname: Johansson
authors.initials: A
authors.lastname: Hallberg