Iron-Mediated Cleavage of Se—Se Bond for the Synthesis ofα-Arylseleno Carbonyl Compounds

Abstract

In the presence of iron dust, using commercial N,N-dimethylformamide (DMF) as solvent, diaryl diselenides re- acted with α-bromo carbonyl compounds at 90 ℃ under nitrogen atmosphere to afford a series of α-arylseleno carbonyl compounds. The influence of temperature, reaction time, solvent and iron dosage on the reaction was investigated. The results showed that the influence of temperature on the reaction was most obvious. In addition, the influence of carbonyl substituent in α-bromo carbonyl compounds was also more obvious. When carbonyl substituent is phenyl, the yield was lower than that of methyl or alkoxy. A proposal mechanism is that iron dust reacted with diaryl diselenides to give the nucleophilic species ArSeFeSeAr, and nucleophilic species ArSeFeSeAr and electrophilic α-bromo carbonyl compounds occured nucleophilic substitution reaction to obtain the desire products. The method using the iron dust to promote the cleavage of Se—Se bond has advantages of safe non-toxic, cheap and easy to get raw materials, simple procedure. Keywords iron dust; cleavage of Se—Se bond; diaryl diselenides; α-bromo carbonyl compounds; α-arylseleno carbonyl compounds