Silver-catalyzed pyrazole migration and cycloaddition reaction of diazo pyrazoleamides with ketimines.

A novel pyrazole migration and cycloaddition process is well developed via AgOTf-catalyzed annulation reactions of α-diazo pyrazoleamides with ketimines. This protocol discloses efficient access to synthesize a series of spirooxindole-based β-lactams in good to excellent yields and the diastereoselectivity is switchable by tuning the substituents on the α-diazo pyrazoleamides.