Magnetically recoverable nano-catalysts in sulfoxidation reactions

Abstract

The sulfoxidation of sulfides have received special attention in organic synthesis especially in medical chemistry because compounds containing S=O bonds (sulfoxides) are privileged structural scaffolds for building pharmacologically and biologically active molecules. Magnetic separation is an efficient strategy for the rapid separation of catalysts from reaction medium and an alternative to time-, solvent-, and energy-consuming separation techniques. In recent times, many protocols based on using magnetically recoverable nano-catalysts have been reported for the oxidation of sulfides to the sulfoxides. This review is focused on metal complexes, acid, and bromine reagents supported on magnetic nanoparticles and their applications as magnetically recoverable nano-catalysts in the sulfoxidation reactions.

Magnetically Recoverable Catalysts: Catalysis in Synthesis of Polyhydroquinolines

“…Formerly, catalysis of chemical and organic reactions by acids has been always a hot research target in organic‐synthesis catalysis. Since the acids are often liquid or expensive, their separation from the reaction media can be regarded as the most important concern of organic chemists . Therefore, designing and fabricating strong solid acids and their utility as catalyst in organic reactions have been viewed as the fundamental challenge ahead of organic synthesis, in particular from the green chemistry point of view .…”

“…Since the acids are often liquid or expensive, their separation from the reaction media can be regarded as the most important concern of organic chemists . Therefore, designing and fabricating strong solid acids and their utility as catalyst in organic reactions have been viewed as the fundamental challenge ahead of organic synthesis, in particular from the green chemistry point of view . In fact, the immobilization of acidic functional groups on magnetic nanoparticles and their catalytic utility in chemical and organic reactions can be considered as the ideal and fascinating solutions to overcome this blind spot due to the fact that the catalyst can be readily separated from the reaction media by an external magnet.…”

“…Catalysis research under bromine is a well‐known topic in organic synthesis . However, the hazardous and toxic nature of bromine and its negative and deleterious effects on the human health have forced the organic chemists to avoid working on bromine . Furthermore, the separation of bromine‐source catalysts from the desired products or the reaction media is a difficult, tedious and time‐consuming task and needs a series of costly and specific techniques .…”

“…However, the hazardous and toxic nature of bromine and its negative and deleterious effects on the human health have forced the organic chemists to avoid working on bromine . Furthermore, the separation of bromine‐source catalysts from the desired products or the reaction media is a difficult, tedious and time‐consuming task and needs a series of costly and specific techniques . In order to overcome this drawback, the hetrogenazition of bromine sources on magnetic nanoparticles can be considered as an efficient and fascinating catalytic system, due to the fact that the catalyst can be readily separated from the reaction mixture by an external magnet .…”

CoFe2O4@SiO2‐CPTES‐Guanidine‐Cu(II): A novel and reusable nanocatalyst for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones and polyhydroquinolines and oxidation of sulfides

“…Sulfoxides have very important structures because they contain S═O bonds and are privileged structural scaffolds for building pharmacologically and biologically active molecules as well as because of their unique properties, such as central chirality at the sulfur, high configurational stability and the strongly polarized S═O bond, which have attracted the attention of researchers. In addition, organic sulfoxides are used as versatile synthetic intermediates in the generation of numerous natural products and biologically active compounds …”