Electrophilic organic selenium reagents—protonated seleninic acids as precursors for unsymmetrical aromatic selenides
摘要:
Arylselenylations of methylbenzenes, methoxybenzenes and thiophene were smoothly achieved with selenenium ions generated by comproportionation of 1:1 mixtures of p-toluenesulfonic acid salts of seleninic acids and the corresponding diselenides. A series of p-toluenesulfonic salts of seleninic acids were prepared by hydrogen peroxide oxidation of the corresponding diselenides in the presence of p-toluenesulfonic acid. Novel 2-(organylseleno)thiophenes were obtained by heating the protonated seleninic acids with a 50-fold excess of thiophene in glacial acetic acid. (C) 2011 Published by Elsevier Ltd.
The use of an air‐ and moisture‐stable dinuclear PdI complex as an efficient catalyst for the formation of C(sp2)−SeR bonds is here reported. The privileged reactivity of the PdI dimer allows for the direct use of selenolates as nucleophiles in the cross‐coupling. Although previous methodologies suffer from catalyst poisoning through the formation of Pd‐ate complexes, the mechanistically distinct dinuclear