Copper-Catalyzed Aerobic Oxidative Dicarbonylation of Indoles toward Solvatochromic Fluorescent Indole-Substituted Quinoxalines

Copper-catalyzed, aerobic, oxidative, C3-dicarbonylation of indoles has been realized directly from alpha-hydroxyketones, which serve as an efficient dicarbonylative reagent under mild conditions. The method is widely compatibility with various functional groups, offering a straightforward means to produce different heterocycle-substituted quinoxalines in excellent yields. These diverse fluorescent quinoxalines exhibited photophysical properties and solvatochromism in certain rules. Based on control experiments, a plausible reaction mechanism was proposed.