NIS‐Mediated Olefination of Quinoxalin‐2(1 H )‐Ones Using Ketone Derivatives: A Facile Synthetic Access to ( Z )‐Enaminone Frameworks

A metal‐free, sustainable protocol for the regioselective C3‐olefination of quinoxalin‐2(1 H )‐one was developed. This transformation utilizes acetophenones for the olefination and N ‐iodosuccinimide as an environmentally benign reagent. The reaction proceeds efficiently under mild conditions, demonstrating broad substrate scope, scalability, and affording ( Z )‐configured enaminone products selectively in good to excellent yields up to 93%. Mechanistic investigations, control experiments, and DFT studies revealed a radical pathway leading to C─C bond formation. The structural properties of the prototype compound 3a were determined using IRI and RDG plot graphs. In addition, the fluorescence properties exhibited by quinoxalinone–enaminone derivatives ( 3a , 3b , 3g ) prompted a preliminary photophysical analysis, probing the influence of electronic substituents through absorption and emission spectral studies. This sustainable and operationally simple approach not only provides access to biologically relevant quinoxalinone derivatives but also offers promising potential in drug discovery and material science.