Carbacephems and 4-methylene-axetidin-2-ones by copper-mediated amide nitrogen-vinylic carbon ring closure

Abstract Treatment of N-alkyl or N-aryl 3-bromo-3-buteneamides under modified Ullmann-Goldberg conditions results in the direct formation of highly strained N-substituted 4-methylene-axetidin-2-ones in fair to good yields. In the same manner, 4-(4′-bromobuten-3′-enyl) acetidinone derivatives provides carbacephems.