Ready Access to 3‐Substituted Quinoxalin‐2‐ones under Superparamagnetic Nanoparticle Catalysis

Abstract Fe 2 O 3 superparamagnetic nanoparticles emerged as a productive recyclable heterogeneous catalyst for the cyclization reaction between α‐keto acids and benzene‐1,2‐diamines to produce quinoxalinones as major products and benzimidazoles as minor products. The Fe 2 O 3 nanoparticles displayed higher activity in the synthesis of quinoxalinones than a series of nano catalysts as well as iron‐, copper‐, nickel‐, and cobalt‐based homogeneous catalysts. Moreover, the Fe 2 O 3 nanoparticles was easily recovered by magnetic decantation, and was reutilized without a remarkable deterioration in catalytic activity and selectivity towards quinoxalinones. To our best knowledge, this transformation was not previously conducted under heterogeneous catalysis conditions.