title: Novel carbonyl bromoallylation/Heck reaction sequence. Stereocontrolled access to bicyclic beta-lactams.
abstract: [reaction: see text] The reaction of 2,3-dibromopropene with racemic as well as enantiopure 4-oxoazetidine-2-carbaldehydes 1 in aqueous media was promoted by tin in the presence of several additives to afford the corresponding bromohomoallyl alcohols 2 in high diastereoselectivities. However, indium or zinc were unable to promote the bromoallylation reaction of aldehydes 1 under similar Barbier-type conditions. Vinyl bromides 2 bearing an extra alkene tether were used for the preparation of differently sized, fused bicyclic beta-lactams of nonconventional structure via Heck cyclization.
authors.affiliation: Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid, Spain. alcaideb@quim.ucm.es
authors.forename: Benito
authors.initials: B
authors.lastname: Alcaide
authors.forename: Pedro
authors.initials: P
authors.lastname: Almendros
authors.forename: Raquel
authors.initials: R
authors.lastname: Rodríguez-Acebes
mesh_terms: D009682:Magnetic Resonance Spectroscopy; D013055:Spectrophotometry, Infrared; D047090:beta-Lactams / Q000737:chemistry*
chemical_list: D047090:beta-Lactams