A total of 20 examples of 2-[(1 H-indol-1-yl)(aryl)methyl]-1,3-diphenylpropane-1,3-diones were efficiently synthesized by the aza-Michael addition at the N1 position of indoles with 2-aroyl-1,3-diarylenones at room temperature in the presence of potassium hydroxide. The salient features of this protocol are no transition-metal catalysts, mild conditions, high chemoselectivity, high atom economy, high yields, and a simple work-up procedure.