Toward a Novel Approach to Bis-β-Lactam Synthesis Using Vilsmeier Reagent as an Efficient Entity via Staudinger Cycloaddition Reaction

A facile synthesis of bis-beta-lactams has been executed using chloromethylenedimethylammonium chloride (Vilsmeier reagent), prepared easily from N,N-dimethylformamide and phosphorus oxychloride. It works out as a versatile acid activator reagent for the direct [2 + 2] ketene-imine cycloaddition of substituted acetic acid and bis-imines in one-pot synthesis under mild conditions. Thus, this method has been proved as a high yielding, efficient, and cheap protocol for bis-beta-lactam synthesis.