A versatile synthesis of fused triazolo derivatives by sequential Ugi/alkyne-azide cycloaddition reactions

We report a facile synthesis of fused dihydrotriazolo[1,5-a]pyrazinones and triazolobenzodiazepines by an Ugi/alkyne–azide cycloaddition synthetic sequence. The coupling of the Ugi multi-component reaction with the intramolecular alkyne–azide cycloaddition provides access to highly functionalized heterocyclic ring systems in two steps from easily available starting materials in excellent overall yields.