Copper catalysis offers an attractive earth-abundant alternative to noble-metal-based carbonylation, yet its application to aryl electrophiles remains severely limited due to the low redox flexibility of Cu(I) and the inhibiting effect of CO coordination. Here we report a photocatalyst-free strategy that overcomes these intrinsic limitations by exploiting in situ generated NHC-stabilized aryl-Cu(I) complexes as bifunctional catalytic species capable of both light absorption and aryl-group transfer. This platform enables the development of copper-catalyzed carbonylation of arylboronic esters using aryl thianthrenium salts as electrophilic coupling partners. The method exhibits a broad substrate scope and high functional-group compatibility, accommodating diverse electron-rich and electron-deficient aromatics as well as structurally complex late-stage scaffolds. This work introduces a generalizable design principle for activating aryl electrophiles under copper catalysis and establishes a dual-functional reactivity mode for Cu(I) species in carbonylation chemistry.
Zhang et al. (Wed,) studied this question.