2-Substituted nitrones and isomeric hydroxylamines – obtained via aluminium amalgam reduction of nitro nitriles and ketones—a new access to convenient intermediates for nitroso carbonyl compounds preparation

A New Approach to Nitrones through Cascade Reaction of Nitro Compounds Enabled by Visible Light Photoredox Catalysis

“…Nitrones have usually been prepared by condensation reactions between carbonyl compounds and oxidation of amines, imines, or hydroxylamines, as well as by the reduction of nitroalkanes . Other recent preparations include copper-mediated coupling of fluorenone oxime and vinyl boronic acid, reduction of nitro nitriles, and cyclization of β-allenyloximes . Despite the versatility of the syntheses of nitrones, mild, efficient, and convenient approaches to nitrones from nitro compounds have been limited, and the harsh reagents and conditions for the previous methods have limited the application of such advances …”

Palladium-Catalyzed Synthesis of Nitrones Via Redox Cross-Coupling of Nitro Compounds and Alcohols

“…Many powerful synthetic methods of nitrones have been reported in the last two decades, such as the oxidation of N,N -disubstituted hydroxylamines, secondary amines and imine, and the condensation reaction of hydroxylamines with carbonyl compounds, allenes, acetylenes, and alkenes, but most of these reactions require additional oxidant or unstable reagents. Besides, the copper-mediated coupling of fluorenone oxime with vinyl boronic acid, the reduction of nitro nitriles, and cyclization of β- allenyloximes have been used to synthesize nitrone too …”