Metal-Free Aerobic Oxidation of Nitro-Substituted Alkylarenes to Carboxylic Acids or Benzyl Alcohols Promoted by NaOH

Efficient
and selective aerobic oxidation of nitro-substituted
alkylarenes to functional compounds is a fundamental process that
remains a challenge. Here, we report a metal-free, efficient, and
practical approach for the direct and selective aerobic oxidation
of nitro-substituted alkylarenes to carboxylic acids or benzyl alcohols.
This sustainable system uses O2 as clean oxidant in a cheap
and green NaOH/EtOH mixture. The position and type of substituent
critically affect the products. In addition, this sustainable protocol
enabled gram-scale preparation of carboxylic acid and benzyl alcohol
derivatives with high chemoselectivities. Finally, the reactions can
be conducted in a pressure reactor, which can conserve oxygen and
prevent solvent loss. The approach was conducive to environmental
protection and potential industrial application.