Determination of the promoting effect of nano SiO₂ and H₃PO₄@nano SiO₂ in the thiocyanation of N-containing aromatic compounds under solvent-free conditions

Abstract

Silica nanoparticles/ammonium thiocyanate (nano SiO₂/NH₄SCN) and H₃PO₄ embedded on nano silica (H₃PO₄@nano SiO₂) in the presence of NH₄SCN were found to be effective systems for the thiocyanation of some arylamines and indoles to afford their corresponding thiocyanated adducts at 70°C under solvent-free conditions. The recovery and reusability of nano SiO₂ as a prompting system have been investigated. A simple procedure for the synthesis of H₃PO₄@nano SiO₂ has also been represented. In addition, a plausible mechanism of thiocyanation has also been suggested.

GRAPHICAL ABSTRACT

Keywords:

• thiocyanation
• indole
• nano SiO₂
• H₃PO₄@nano SiO₂
• solvent-free conditions

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

The authors acknowledge the financial support from the Research Council of Alzahra University.