Visible-Light-Mediated Ruthenium-Catalyzed para-Selective Alkylation of Unprotected Anilines

Anilines are important moieties in organic chemistry,pharmaceuticals,and materials science. Although para-selective functionalizationof anilides and tertiary anilines is well established, unprotectedanilines have posed a challenge. Herein, we report visible-light-mediatedRu-(II)-catalyzed para-alkylation of anilines. Thedistinct Ru-(II)-aniline complex enabled the reaction to proceedwith extremely high efficiency (2 h) under mild conditions. The goodfunctional group tolerance allowed late-stage functionalization andeven aggregation-induced emission luminogen labeling of natural productsand drugs. A mechanistic investigation suggests that the Ru-(II)-anilinecomplex is crucial for both triggering the reaction and controllingthe para-selectivity.