Impact of Carboxyl Groups in Graphene Oxide on Chemoselective Alcohol Oxidation with Ultra-Low Carbocatalyst Loading

Yan Cui,Jung Woon Yang,Young Hee Lee

doi:10.1038/s41598-017-03468-4

Abstract

A highly efficient and simple chemoselective aerobic oxidation of primary alcohols to either aldehydes or carboxylic acids in the presence of nitric acid was developed, utilising 5 wt% graphene oxide as a carbocatalyst under ambient reaction conditions. Carboxylic acid functional groups on graphene oxides played a vital role in carbocatalyst activity, greatly influencing both the reactivity and selectivity. We also applied this protocol to a variant of the Knoevenagel condensation for primary alcohols and malonates with a secondary amine co-catalyst via cooperative catalysis.

Highlights

1a with diethyl malonate 4a was performed in the presence of both 20 mol% secondary amine catalyst and 5 wt
A 10-mL two necked, round-bottomed flask equipped with a magnetic stirring bar, a reflux condenser, and a glass stopper was charged with the corresponding primary alcohol (1 mmol) and graphene oxide (5 wt%) in 1,4-dioxane (2 mL)
The residue was purified by column chromatography on silica gel with diethyl ether and pentane as the eluting solvents to afford the corresponding aldehyde

Summary

Introduction

1a with diethyl malonate 4a was performed in the presence of both 20 mol% secondary amine catalyst and 5 wt. Product chemoselectivity with different carboxylic acid contents; (ii) demonstrating their application to cooperative catalysis of a variant of the Knoevenagel condensation between benzyl alcohol and malonate; and (iii) showing the recyclability of the GO carbocatalyst without a significant decrease in product chemoselectivity. General procedure for oxidation of alcohol to aldehyde. A 10-mL two necked, round-bottomed flask equipped with a magnetic stirring bar, a reflux condenser, and a glass stopper was charged with the corresponding primary alcohol (1 mmol) and graphene oxide (5 wt%) in 1,4-dioxane (2 mL).

Results

Conclusion