Efficient CuCl-Catalyzed Selective and Direct Oxidation of β- and γ-Substituted Aliphatic Primary Alcohols to Carboxylic Acids

Abstract

A new procedure for the selective and direct oxidation of aliphatic primary alcohols having substitution at β- and γ-positions to corresponding carboxylic acids was developed using a catalytic amount of ligand and additive-free CuCl with anhydrous ^t BuOOH in acetonitrile solvent under very mild reaction conditions. This procedure is very simple and mild and works efficiently without any additives at room temperature.

Keywords:

• Aliphatic primary alcohols
• carboxylic acids
• copper catalyst
• direct oxidation
• selective oxidation
• tertiary butyl hydroperoxide

ACKNOWLEDGMENTS

We thank the Department of Science and Technology (DST; Project No. SR/S1/OC-06/2008), New Delhi, for the financial support. S. M. thanks the Council of Scientific and Industrial Research, New Delhi, for a senior research fellowship. We thank the DST, New Delhi, for the funding of the 400-MHz NMR machine to the Department of Chemistry, IIT, Madras, under the IRPHA scheme and the electrospray ionization–mass spectrometry instruments under the Funding for Infrastructure in Science and Technology program.

Notes

^a Isolated yield.

^a Reaction conditions: 5 mol% of CuCl, 5 equiv. of 5M ^t BuOOH (in decane) in MeCN at room temperature.

^b Isolated yield. All the products were fully characterized by ¹H and ¹³C NMR, FT-IR, and mass spectroscopy.