Unprecedented binary Cu(I)/Cu(II) catalyzed one-pot, three-component synthesis and evaluation of luminescent property of 2-amino-3-iminoethenylidene-2-indolones: a new class of merocyanine dye analogues.

A facile and efficient binary Cu(I)/Cu(II) catalyzed one-pot, three-component synthesis of 2-amino-3-iminoethenylidene-2-indolones in excellent yield has been achieved. Remarkably, these newly synthesized, stable merocyanine dye analogues showed strong luminescence in the blue region with large Stokes shifts.