title: Dimethylzinc-Initiated Radical Coupling of β-Bromostyrenes with Ethers and Amines.
abstract: A new coupling reaction has been developed in which β-bromostyrenes react with ethers and tertiary amines to introduce the styryl group in the α-position. The transformation is mediated by Me2 Zn/O2 with 10 % MnCl2 and is believed to proceed by a radical addition-elimination mechanism. The ether and the amine are employed as solvent and the coupling takes place through the most stable α radical for unsymmetrical substrates. The products are obtained in moderate to good yields as the pure E isomers. The coupling can be achieved with a range of smaller cyclic and acyclic ethers/amines as well as various substituted β-bromostyrenes.
authors.affiliation: Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark).
authors.forename: Amanda
authors.initials: A
authors.lastname: Sølvhøj
authors.affiliation: Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark).
authors.forename: Andreas
authors.initials: A
authors.lastname: Ahlburg
authors.affiliation: Department of Chemistry, Technical University of Denmark, 2800 Kgs. Lyngby (Denmark). rm@kemi.dtu.dk.
authors.forename: Robert
authors.initials: R
authors.lastname: Madsen
keywords: CC coupling; CH activation; amines; radical reactions; synthetic methods