Vinyl-β-lactams as Efficient Synthons. Eco-friendly Approaches via Microwave Assisted Reactions

Vinyl-β-lactams are efficient synthons for a variety of compounds of biomedical interest—such as isocephalosporins, carbapenem and thienamycin intermediates, and pyrrolidine alkaloids. Convenient methods are described for obtaining both enantiomers of some of these synthons. Microwave-induced Organic Reaction Enhancement (MORE) chemistry techniques allow highly accelerated synthesis of variously substituted vinyl-β-lactams using limited amounts of solvents and with efficient stereocontrol—thus achieving high ‘atom economy’. The effect (if any) of microwaves on bond angles and bond lengths and the geometry of transition states are not well understood yet. Nonetheless, reactions under microwave irradiation in open systems are rapid, safe, and cost-effective for synthetic approaches that are much more friendly to the environment than conventional processes.