Search

Oxone mediated reaction of imidazo[2,1-b]thiazole, imidazo[1,2-a]pyridine and 1H-pyrazole derivatives with diaryl diselenides is presented here. The methodology represents an efficient and simple protocol for carrying out the selective synthesis of 5-arylselanyl-imidazo[2,1-b]thiazoles, 3-arylselanyl-imidazo[1,2-a]pyridines and 4-arylselanyl-1H-pyrazoles in high yields using a stable, nontoxic and cheap oxidant. The reactions were conducted at 60 °C in air using acetonitrile as solvent. Alternatively, the use of ultrasound irradiation is presented as a tool for fast and efficient energy transfer that significantly reduced the reaction time.

Organochalcogen compounds present synthetic and biological applications of extreme relevance. The coupling reaction between boronic acids, borate anions or boronic esters with different sources of chalcogen (S, Se and Te), mediated by transition metals, is a powerful tool for the formation of functionalized diorganyl chalcogenides. By this strategy, selenides, sulfides, and tellurides with high complexity and molecular diversity can be prepared in good to excellent yields. This review covers the use of organoboron compounds as a versatile reagent for the formation of Carbon–Chalcogen bonds using different metallic catalysts (Cu, Ag, Pd, Fe, In, Rh, Ni).

Two new organochalcogen-containing zingerone derivatives, 4-(4-hydroxy-3-methoxyphenyl)-4-(phenylseleno)-2-butanone ( 2b ) and 4-(4-hydroxy-3-methoxyphenyl)-4-(phenylthio)-2-butanone ( 2c ) were prepared and evaluated for their antioxidant properties. DPPH and lipid peroxidation studies show that 2b and 2c have significantly improved antioxidant activity over dehydrozingerone ( 1 ) despite having similar electron transfer capacity. We speculate that the improved activity of 2b and 2c is partly due to the ability of these compounds to act twice as phenolic antioxidants through a mechanism that eliminates phenylselenyl or phenylthiyl radicals.