An expedient synthesis of 1,2-dihydrobenzo[g]quinoline-5,10-diones via copper(II) triflate-catalyzed intramolecular cyclization of N-propargylaminonaphthoquinones

An expedient synthesis of a series of 1,2-dihydrobenzo[g]quinoline-5,10-diones in good yields has been accomplished via three-component one pot sequential reactions of 2-hydroxynaphthalene-1,4-dione, substituted anilines and propargyl as well as 3-ethylpropargyl bromides furnishing N-propargylaminonaphthoquinones, and their concomitant copper(II) triflate-catalyzed intramolecular 6-endo-dig cyclization.