Catalytic and non-catalytic addition of aromatic amines to terminal acetylenes in the presence of mercury(II) chloride and acetate

The addition of aromatic amines to terminal acetylenes in the presence of catalytic amounts of mercury(II) chloride gives imines, enamines, and 1,2,3,4-tetrahydroquinoline derivatives; mercury(II) acetate shows considerably less catalytic activity and may be used for the non-catalytic preparation of imines, enamines, NN′-disubstituted acetamidines, and NN-disubstituted acetamides.