A Ni(iii) complex stabilized by silica nanoparticles as an efficient nanoheterogeneous catalyst for oxidative C–H fluoroalkylation

Abstract

We have developed Ni^III-doped silica nanoparticles ([(bpy)_xNi^III]@SiO₂) as a recyclable, low-leaching, and efficient oxidative functionalization nanocatalyst for aromatic C–H bonds. The catalyst is obtained by doping the complex [(bpy)₃Ni^II] on silica nanoparticles along with its subsequent electrooxidation to [(bpy)_xNi^III] without an additional oxidant. The coupling reaction of arenes with perfluoroheptanoic acid occurs with 100% conversion of reactants in a single step at room temperature under nanoheterogeneous conditions. The catalyst content is only 1% with respect to the substrates under electrochemical regeneration conditions. The catalyst can be easily separated from the reaction mixture and reused a minimum of five times. The results emphasize immobilization on the silica support and the electrochemical regeneration of Ni^III complexes as a facile route for developing an efficient nanocatalyst for oxidative functionalization.