Application of the Povarov Reaction in Biaryls under Iron Catalysis for the General Synthesis of Dibenzo[a,c]Acridines

A modified Povarov reaction involving 2′-alkynylbiaryl-2-carbaldehydes and aryl amines with tandem oxidation was performed using catalytic FeCl3. The outcome was an efficient general synthesis of dibenzo­[a,c]­acridines with moderate to high yields. This method offers simplicity in the preparation of substrates, diverse substrate scope, and high atom economy. The generality of the protocol was verified by synthesizing a tribenzo­[a,c,h]­acridine derivative. Photophysical properties of the synthesized compounds were also studied. The compounds absorb UV light typically in the range 230–330 nm and emit in the visible range of 400–420 nm.