“Metal-free” electrooxidative C—H thiocyanation of arenes

Recent advances in photochemical and electrochemically induced thiocyanation: a greener approach for SCN-containing compound formation

Techniques utilizing photo- and electrochemically induced reactions have been developed to accelerate organic processes. These techniques use light or electrical energy (electron transfer) as a direct energy source without using an initiator or reagent. Thiocyanates are found in biologically active and pharmacological compounds and can be converted into various functional groups. It is one of the most prominent organic scaffolds. Significant development in photo- and electro-chemically induced thiocyanation procedures has been made in recent years for the conception of carbon-sulfur bonds and synthesis of pharmaceutically important molecules. This review discusses different photo- and electro-chemically driven thiocyanation C(sp3)-SCN, C(sp2)-SCN, and C(sp)-SCN bond conception processes that may be useful to green organothiocyanate synthesis. We focus on the synthetic and mechanistic characteristics of organic photo- and electrochemically accelerated C-SCN bond formation thiocyanation reactions to highlight major advances in this novel green and sustainable research field.

Electrooxidation Is a Promising Approach to Functionalization of Pyrazole-Type Compounds

The review summarizes for the first time the poorly studied electrooxidative functionalization of pyrazole derivatives leading to the C-Cl, C-Br, C-I, C-S and N-N coupling products with applied properties. The introduction discusses some aspects of aromatic hydrogen substitution. Further, we mainly consider our works on effective synthesis of the corresponding halogeno, thiocyanato and azo compounds using cheap, affordable and environmentally promising electric currents.

A New Method for the Synthesis of 3-Thiocyanatopyrazolo[1,5-a]pyrimidines

In this article, we demonstrate how an original effective "metal-free" and "chromatography-free" route for the synthesis of 3-thiocyanatopyrazolo[1,5-a]pyrimidines has been developed. It is based on electrooxidative (anodic) C-H thiocyanation of 5-aminopyrazoles by thiocyanate ion leading to 4-thiocyanato-5-aminopyrazoles (stage 1, yields up to 87%) following by their chemical condensation with 1,3-dicarbonyl compounds or their derivatives (stage 2, yields up to 96%). This method is equally effective for the synthesis of 3-thiocyanatopyrazolo[1,5-a]pyrimidines, both without substituents and with various donor (acceptor) substituents in the pyrimidine ring.