Recent advances in using 4DPAIPN in photocatalytic transformations.

1,3-Dicyano-2,4,5,6-tetrakis(diphenylamino)-benzene (4DPAIPN), with diphenylamino as an electron donor and dicyanobenzene as an electron acceptor, is a typical donor-acceptor fluorophore. Due to its excellent redox window, good chemical stability and broad applicability, this fluorophore has emerged as a powerful and attractive metal-free organophotocatalyst. This review has highlighted the design, synthesis and application of 4DPAIPN photoredox catalysts as well as their exceptionally broad range of redox properties. This flourishing class of organophotocatalysts is expected to contribute to a great extent toward the advancement of synthetic methodologies and its adaptation to a large scale inventive implementation due to their flexibility.