Chemoselective Oxidation of Sulfides and Oxidative Coupling of Thiols by a New Polyoxometalate and Heterogeneous Cobalt and Molybdenum Hybrid Nanocatalyst Stabilized on Modified Mesoporous CMK-3

Abstract

In this work, a new heterogeneous cobalt and molybdenum hybrid-substituted polyoxometate was stabilized on mesoporous CMK-3 (PMo11Co@CMK-3) as a durable, effectual, recyclable, environment-friendly, and chemoselective nanocatalyst. PMo₁₁Co@CMK-3 catalyst was identified by various techniques such as BET, SEM, EDS, and FT-IR. Sulfoxides and disulfides were formed using PMo₁₁Co@CMK-3 through selective sulfides oxidation and oxidative coupling of thiols, respectively. The proposed method is an effective method, and the mentioned reactions are performed in a short time with very high efficiency. In order to produce sulfoxides and disulfides, hydrogen peroxide (H₂O₂) was selected as an environmentally friendly, safe, attainable, and inexpensive oxidant, with only water as a byproduct. This catalyst shows the heterogeneous and insolubility nature, notable chemoselectivity, good durability, and reusability in the oxidation of sulfides and oxidative coupling of thiols. In addition, sulfoxides and disulfides were synthesized under solvent-free conditions, which is an ideal condition for environmental health and economic savings. All sulfoxide and disulfide products were obtained with high yields within short reaction times.