Visible-Light photocatalytic One-Pot Synthesis of Aldonitrones using CdS nanorodes

Photocatalytic reactions by using semiconductors for organic transformation at different conditions such as various solvents, light sources and catalysts are taken in to consideration1.CdS has been introduced as suitable photocatalyst due to its unique photoelectric properties such as narrow band gap (2.4 eV) and its activity in a wide range of sunlight irradiation2. Nitrones as protected form of hydroxylamines are key intermediates for synthesis of biologically active compounds and natural products3.During the reduction of nitro aromatic compounds, unstable intermediates (e.g. nitroso, hydroxylamine) can be produced. In situ generation of unstable hydroxylamine and its reaction with a carbonyl compound is the mildest and most atom-efficient procedure for nitrone synthesis and also minimizes the synthetic steps.Nanorod CdS photocatalyst has been used for reduction of nitroarenes in water. Reduction of nitro to amines was done in water under green and blue LED irradiation. Also reduction of nitroarenes in the presence of aldehydes for synthesis of nitrones were done successfully under blue LED irradiation. As our best knowledge,this is the first photocatalytic synthesis of nitrone by aldehyde and nitroarenes using a semiconductor as photocatalyst. In this reaction 1mmol of starting materials was used that is very interesting in heterogeneous photocatalysis.