Nano copper oxide catalyzed synthesis of symmetrical diaryl sulfides under ligand free conditions

K Harsha Vardhan Reddy,G Kranthi,V Prakash Reddy,A Ashwan Kumar,Yvd Nageswar

doi:10.3762/bjoc.7.101

Abstract

Potassium thiocyanate acts as an efficient sulfur surrogate in C–S cross-coupling reactions mediated by recyclable copper oxide nanoparticles under ligand free conditions. This protocol avoids foul smelling thiols, for the synthesis of a variety of symmetrical diaryl sulfides, via the cross-coupling of different aryl halides with potassium thiocyanate, affording corresponding products in moderate to excellent yields.

Highlights

After the discovery of copper-promoted Ullmann reaction [1,2,3] for the construction of carbon-hetero atom bonds, several protocols have been reported over the years to establish C–N, C–O, and C–S linkages
In continuation of our investigations on metal-catalyzed crosscoupling reactions, we have explored the CuO-catalyzed synthesis of diaryl sulfides under ligand-free conditions (Scheme 1)
To the best of our knowledge, this is the first recyclable copper oxide nanoparticle-catalyzed cross-coupling of aryl halides with potassium thiocyanate [46,47,48,49,50,51]

Summary

Introduction

After the discovery of copper-promoted Ullmann reaction [1,2,3] for the construction of carbon-hetero atom bonds, several protocols have been reported over the years to establish C–N, C–O, and C–S linkages. Most of these coupling protocols involve the reaction between thiols and aryl halides, resulting in the formation of C–S bonds. Come these problems, Zhou [43] and coworkers recently reported an efficient C–S bond formation by the reaction of potassium thiocyanate and aryl halides in the presence of a copper catalyst and a ligand in aqueous medium at 130 °C for 48 h.

Results

Conclusion