Aim and Objective: A simple catalytic method has been developed to achieve the reduction of nitroarenes
with NaBH4 using diphenyl diselenide catalyst in order to obtain the azoxyarene, azoarene products
under mild conditions.
Materials and Methods: The reduction of different substituted nitroarenes was realized in alkaline ethanolic
solution using mild sodium borohydride in the presence of diphenyl diselenide as an electron-transfer catalyst.
The reactions were performed sometimes at room temperature and sometimes at refluxing conditions.
Results: Diphenyl diselenide which is reduced to sodium phenylselenolate, presenting an electron transfer
agent successfully permitted to reduce several nitroarenes, bearing different substituent groups whose electronic
effects promote the formation of the azoxy or azo compounds.
Conclusion: Treatment of nitroarenes with sodium borohydride in alkaline ethanol in the presence of catalytic
amounts of diphenyl diselenide at room temperature leads to obtain the corresponding azoxy compounds in
good yields by reaction with sodium phenylselenolate generated in situ. At higher temperature, further reduction
to azo compounds occurs. Therefore, the results have indicated that the electronic effects of substituent
groups rigorously take part in determination of their reduction efficiencies.