Halogen–metal exchange reactions of bromoaryl-substituted β-lactams

Abstract

Abstract β-Lactams are quite susceptible to ring opening when exposed to nucleophilic reagents. The robustness of a variety of bromo- and iodoarenes containing electrophilic functional groups toward alkyllithium reagents during the halogen–lithium exchange process was first described by Parham, Bradsher, and co-workers. These observations led us to consider the behavior of bromoaryl-substituted β-lactams when treated with n-butyllithium at −100 °C in tetrahydrofuran. The work discussed herein describes successful halogen–metal exchange reactions on haloarene-substituted β-lactams thereby permitting a method for aromatic ring elaborations in the presence of the highly electrophilic β-lactam ring.