Metal‐Free Decarboxylative Alkylation of Quinoxaline‐2(1 H )‐ones Enabled by Heterogeneous g‐C 3 N 4 Photoredox Catalysis

A sustainable protocol for the direct C3‐alkylation of quinoxalin‐2‐ones using graphitic carbon nitride (g‐C 3 N 4 ) as a heterogeneous photocatalyst is reported. This article is the first to use g‐C 3 N 4 to enable N‐heterocyclic alkylation via direct decarboxylation, thereby overcoming the limitations of homogeneous Ir/Ru systems. The reaction proceeds under mild conditions with O 2 as the oxidant, tolerating diverse functional groups and affording products in 65%–92% yields. The g‐C 3 N 4 catalyst, prepared from earth‐abundant precursors, is readily recycled by centrifugation and maintains its activity over five cycles. This method offers advantages in cost, environmental impact, and scalability, making it a green and promising candidate for industrial applications.