SILICA PHOSPHORIC ACID/NaNO₂ AS A NOVEL HETEROGENEOUS SYSTEM FOR THE COUPLING OF THIOLS TO THEIR CORRESPONDING DISULFIDES

Abstract

Silica phosphoric acid was prepared via reaction of silica chloride (I) and phosphoric acid. Thiols can be readily converted to their corresponding thionitrites with a combination of silica phosphoric acid (II), wet SiO ₂ , and sodium nitrite in dichloromethane at room temperature. Disulfides result from the homolytic cleavage of the sulfur–nitrogen bond of the unstable thionitrite and subsequent coupling of the resultant thiyl radicals.

Keywords:

• Disulfides
• silica chloride
• silica phosphoric acid
• thiols
• thionitrites (S-nitrosothiols)

Acknowledgments

Financial support for this work from the Research Council of Bu-Ali Sina University, Hamadan, Iran is gratefully acknowledged.