Highly efficient, green, rapid, and chemoselective oxidation of sulfur-containing compounds in the presence of an MCM-41@creatinine@M (M = La and Pr) mesostructured catalyst under neat conditions

In the present study, we report the synthesis of two green recoverable catalysts by covalent linking of the creatinine La and Pr complexes on an MCM-41 mesostructure with the commercially available materials and via a simple and inexpensive procedure. These heterogeneous catalysts were characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, scanning electron microscopy, N-2 adsorption and desorption, inductively coupled plasma optical emission spectroscopy, and thermogravimetric analysis. The obtained mesostructures act as active and reusable catalysts for the oxidation of sulfides and oxidative coupling of thiols under neat conditions. More importantly, significant practical advantages of this environmentally friendly process include high efficiency, good reaction times, and convenient recovery and reusability for several times without any significant loss of activity of the catalyst.