An operationally simple catalytic system based on [RuCl2 (p-cymene) 2] was developed for stereoselective cyclization of α-diazoacetamides by intramolecular carbenoid CH insertion, and β-lactams were produced in excellent yields and> 99% cis-stereoselectivity. The Ru- catalyzed reactions can be performed without the need for slow addition of diazo compounds and inert atmosphere. With α-diazoanilides as substrate, the carbenoid ...
