Denitration of Nitroarenes Under Ambient Physiological Conditions Catalyzed by Graphdiyne-Supported Palladium

The direct cleavage of C-NO2 bonds for reductive denitration of nitroarenes remains a challenging transformation in synthetic organic chemistry. Herein, we report a biocompatible palladium-deposited graphdiyne nanocatalyst (Pd@GDY/DSPE-PEG) that can catalyze reductive denitration of nitroarenes under ambient physiological conditions. Mechanistic studies support this transformation via the oxidative addition of nitroarenes with Pd(0) and subsequent ligand exchange to form arylpalladium hydride. This one-step reductive denitration via Pd@GDY/DSPEPEG successfully facilitates the repair of the nitrated proteins arising from endogenic ONOO- and restores their physiological function, including blocking the apoptosis pathway in living cells. Moreover, Pd@GDY/ DSPE-PEG was further successfully applied for catalytic denitration to reduce the level of 3-nitrotyrosine residues of proteins located in the mouse brain hippocampus in vivo. This study provides an ideal strategy for designing highly active enzymatic mimicking synthetic catalysts for the regulation of the nitrated protein level and the detoxification of nitrative damage of living cells and tissues.