An operationally simple, one-pot multicomponent reaction has been developed for the assembly of 9H-benzo[f]imidazo[1,2-d][1,2,3]triazolo[1,5-a][1,4] diazepines adorned with three diversification points via an atom-economical transformation incorporating α-diketones, o-azidobenzaldehydes, propargylic amines, and ammonium acetate. This process involves tandem InCl 3-catalyzed cyclocondensation and intramolecular azide-alkyne 1,3-dipolar cycloaddition reactions; optimization data, substrate scope, and mechanistic insights are discussed. © 2013 American Chemical Society.