Application of raw and chemically modified biomasses for heterogeneous Cu-catalysed conversion of aryl boronic acids to phenols derivatives.

Abstract

This work describes the application of raw and chemically modified cellulose and sug- arcane bagasse for ipso-hydroxylation of aryl boronic acids in environmentally friendly reaction

conditions. The catalytic efficiency of five support-[Cu] materials was compared in forming phenols from aryl boronic acids. Our investigation highlights that the CEDA-[Cu] material (6-deoxy-6- aminoethyleneamino cellulose loaded with Cu) leads to the best results under very mild reaction conditions. The optimized catalytic sequence, allowing a facile transformation of boronic acids to phenols, required the mandatory and joint presence of the support, Cu2O, and KOH at room temperature. CEDA-[Cu] was characterized using 13C solid-state NMR, ICP, and FTIR. The use of CEDA-[Cu] accounts for the efficacious synthesis of variously substituted phenol derivatives and presents very good recyclability after five catalytic cycles.