Lewis acid mediated functionalization of β-lactams: mechanistic study and synthesis of C-3 unsymmetrically disubstituted azetidin-2-ones

Direct and diastereoselective alkylation and aldol reactions of α-bromo-α-fluoro-β-lactams

Herein, we describe the development of a method for the direct alkylation and aldol reaction of α-bromo-α-fluoro-β-lactams. This method provides facile access to a wide range of 3-alkyl- and 3-hydroxyalkyl-fluoro-β-lactams in good yields under mild conditions. The products were obtained with complete diastereoselectivity with regard to the relative configuration of the β-lactam ring at C3 and C4 positions. The reaction conditions were tolerant of a broad range of electrophiles, which highlights the overall scope and utility of this procedure.