Photoactive Arylamine Appended β‐Naphthols via Friedel–Crafts Alkylation of Vinylidine Quinone Methides (VQMs)

Substituted naphthol derivatives have received significant attention due to their wide range of biological and pharmaceutical activities, and further extending the generation of naphthol with photoactive materials promotes optoelectronic applications. Nevertheless, the synthetic methodology of such materials hitherto unknown. In this study, we have adopted an efficient Friedel-Crafts reaction of ortho-alkynylnaphthols with N,N-disubstituted arylamines to generate arylamine-appended β-naphthol derivatives. This transformation features broad substrate scope, excellent yields, and high atom economy and the method was successfully adapted for late-stage functionalization of biomolecules and drug molecules with excellent yields. Further, UV-vis absorption and emission studies reveal that these materials have shown visible range absorption and blue emission with a quantum efficiency of 10%. Lately, photo-irradiation on arylamine leads to a charged state that facilitates the improvement of the electronic properties. Consequently, novel synthetic methodology of photoactive materials paves the way to generate new developments in the area of small molecule-derived optoelectronics.