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

A series of nitroalkanes were efficiently transformed to alkylnitrones using a visible light irradiation photocatalytic process. The mild, efficient, and environmentally benign reaction method, involving dynamic reciprocations of cascade pathways, comprises a mixture of a Ru­(bpy)₃Cl₂ photoredox catalyst and DIPIBA or Hünig’s base in CH₃CN. Notably, DIPIBA was found to be the best additive for the cross condensation reaction of nitroalkanes with aldehydes. The structures of appropriate products were confirmed by X-ray analysis.