Oxidative Coupling of Thiols to Disulfides in Solution with Tripropylammonium Halochromates, (C₃H₇)₃NH[CrO₃X], (X = F, Cl) Adsorbed on Alumina

Abstract

A mild and efficient method for the oxidative coupling of thiols by tripropylammonium fluorochromate and tripropylammonium chlorochromate absorbed on alumina in solution is reported. Alumina absorbed tripropylammonium fluorochromate and tripropylammonium chlorochromate are efficient and new reagents, which are easily prepared and oxidize thiols to the corresponding disulfides quickly. The reactions are clean and readily controlled to stop at the disulfide stage without the formation of common over-oxidized side products. Thus the advantages of the easy procedure and work up, short reaction times, and excellent yields make this a viable alternative method.

Keywords:

• Alumina
• heterogeneous oxidants
• thiols
• tripropylammonium chlorochromate(VI)
• tripropylammonium fluorochromate(VI)

Acknowledgments

The author thanks Dr. A. R. Mahjoub, Mr. M. K. Mohammady, and Mrs. S. Khorsandtabar for valuable discussion.