Application of Raw and Chemically Modified Biomasses for Heterogeneous Cu-Catalysed Conversion of Aryl boronic Acids to Phenols Derivatives

Fernanda Guimarães Torres,Olfa Zayene,Damien Prim,Flavien Bourdreux,Anne Gaucher,Filipe Simões Teodoro,Leandro Vinícius Alves Gurgel,Laurent Frédéric Gil

doi:10.3390/catal12010092

Abstract

This work describes the application of raw and chemically modified cellulose and sugarcane 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.

Highlights

Due to the necessity to use renewable resources versus fossil resources, materials prepared from biomass, such as chitosan, sugarcane bagasse or cellulose, are of particular interest [1,2,3,4]
SSiimmiillaarrllyy, CEDA is readily prepared from ccellulose through a sshhoorrt oonnee--ppot ttwwoo--step ssynthetic sequence involving ttoossyyllaattiioonnffoollolowweeddbbyythteheadaddidtiiotinonofoeftheythleynlendeiadmiaimneinaes raescreenctelyntdlyesdcreisbcerdib[e2d]
We further investigated the ipso-hydroxylation process of valuable 4-bromophenylboronic acid 3 under the conditions mentioned above at room temperature by varying the reaction time

Summary

Introduction

Due to the necessity to use renewable resources versus fossil resources, materials prepared from biomass, such as chitosan, sugarcane bagasse or cellulose, are of particular interest [1,2,3,4]. Biopolymers such as cellulose have received tremendous global attention as a biodegradable, abundant, easy to modify, non-toxic solid support for metal catalysts [5,6]. The ipso-hydroxylation of boronic acids represents one of the preparation routes to phenols. The access to phenols by ipso-hydroxylation of boronic acids can be achieved in three main ways including photocatalysis [18], the use of strong

Methods

Results

Conclusion