Azaanthraquinone PCET Catalysis Enables Chemoselective Decarboxylative Functionalization of Diverse Carboxylic Acids

The advancement of a proton-coupled electron transfer (PCET) strategy holds significance to expand the synthetic applicability and energy efficiency of photoredox chemistry. However, the current implementation of this strategy is typically narrow in terms of the redox potential and quantum yield. In this study, a novel PCET catalyst has been developed for direct decarboxylative functionalization of wide range of carboxylic acids including aromatic carboxylic acids and electron-deficient carboxylic acids. The catalyst exhibits a high triplet energy and intersystem crossing efficiency. These features not only endow it with strong oxidative capability but also effectively minimize detrimental back electron transfer. This catalyst enabled a variety of decarboxylative functionalization reactions to proceed under mild conditions with high chemoselectivity.