Synthesis of Arylidene-β-lactams via <i>exo</i>-Selective Matsuda-Heck Arylation of Methylene-β-lactams

exo-Methylene-β-lactams were synthesized in two steps from commercially available 3-bromo-2-(bromomethyl)propionic acid and reacted with arene diazonium salts a Heck-type arylation the presence of catalytic amounts Pd(OAc)2 under ligand-free conditions. The products, arylidene-β-lactams, obtained high yields as single isomers. β-hydride elimination step Pd-catalyzed coupling reaction proceeds exo-regioselectivity E-stereoselectivity. With aryl iodides, triflates, or bromides, products isolated only low yields, due to extensive decomposition starting material at elevated temperatures. This underlines that can be superior arylating reagents reactions yield synthetically useful selectivities when conventional conditions fail.