Regioselective Synthesis of a Family of β-Lactams Bearing a Triazole Moiety as Potential Apoptosis Inhibitors.

Apoptosis is a biological process important to several human diseases; it is strongly regulated through protein-protein interactions and complex formation. We previously reported the synthesis of apoptosis inhibitors bearing an exocyclic triazole amide isoster by using an Ugi four-component coupling reaction (Ugi-4CC), followed by a base-promoted intramolecular cyclization. Depending on the substitution patterns and the reaction conditions, this cyclization forms the six- or four-membered ring. Two compounds bearing the β-lactam scaffold turned out to be the most potent inhibitors. This encouraged us to optimize the modulation of the cyclization, and prepare a library of 15 β-lactams with total regioselectivity. Moreover, we aimed to improve the bioavailability of these compounds through the introduction of diversity at different substitution positions. The activity of these compounds as apoptosis inhibitors in cellular extracts has been evaluated, showing an increase in their potency.