Mechanochemical multicomponent Ugi-azide/post-transformation strategies. Toward more sustainable one-pot diversity-oriented synthesis of complex nitrogen heterocycles.

Abstract

Rapid, versatile, and efficient mechanochemical one-pot processes were developed for the synthesis of 1,5-disubstituted tetrazoles (1,5-Ds-Ts) and complex analogs, such as bis-heterocycles (BHCs) and polyheterocycles (PHCs), via multicomponent strategies based on the Ugi-azide four-component reaction (UA-4CR) at room temperature under solvent-free or solvent-less conditions. Furthermore, mechanochemical one-pot diversity-oriented synthesis (DOS) was achieved by coupling UA-4CR with post-transformation processes, such as copper-catalyzed alkyne-azide cycloaddition (CuAAC) and 1,5-pseudoelectrocyclization, thereby increasing molecular complexity and diversity of the products.