Visible‐light‐mediated synthesis of 2H-indazoles from (2-bromo-benzylidene)-phenyl-amine derivatives by the Ullmann Goldberg reaction

Abstract

Copper oxide-Titanium dioxide nanocomposites (CuO/TiO₂ NC) is an efficient photocatalyst for the synthesis of 2H-indazoles derivatives through intermolecular C–N bond (Ullmann Goldberg reaction) and intramolecular N–N bond formation. The CuO/TiO₂ NC is a stable photocatalyst and can be reused multiple times without losing its catalytic properties. High yields of product, environmentally friendly, cost-effective method, and easy workup are advantages of the present method. All synthesized compounds were characterized by NMR spectroscopy.