Photocatalytic C3-H acylmethylation of quinoxalinone with sulfoxonium ylides for the synthesis of 3-(γ-dicarbonyl)-quinoxalin-2(1H)-ones

We have developed a method for the acylmethylation of quinoxalin-2(1H)-ones under visible light utilizing sulfoxonium ylides for the first time. This method proves effective not only for 1-methylquinoxalin-2(1H)-ones but also for quinoxalin-2(1H)-ones, yielding a series of novel dual acylmethylation products, namely 3(gamma-dicarbonyl)-quinoxalinones, at room temperature. These target products exhibit potential for further transformation into furan derivatives, thereby enhancing the versatility and applicability of this strategy. Mechanistic studies suggest that this reaction may proceed via two mechanisms: single-electron transfer and energy transfer. This method offers a practical and efficient approach for the acylmethylation of quinoxalin-2(1H)-ones, yielding valuable 3-(gamma-dicarbonyl)-quinoxalin-2(1H)-ones under mild reaction conditions, thus expanding the toolbox of synthetic strategies for the functionalization of quinoxalin-2(1H)-ones. The findings hold implications for drug development, organic synthesis, and materials science, providing a versatile platform for the synthesis of structurally diverse compounds with potential biological and material applications.