Manganese-Catalyzed -Formylation of Anilines Using Oxalic Acid as CO Surrogate.

Formanilides are valuable synthetic intermediates and additives in the rubber industry. Manganese-catalyzed -formylation of aniline using (COOH)·2HO represents a significant advancement in the synthesis of formanilides. This novel approach offers a safe and efficient alternative to traditional carbon monoxide (CO) gas-based formylation reactions, addressing safety concerns and overcoming the challenges associated with handling gaseous CO. By employing (COOH)·2HO as a readily available and environmentally benign CO surrogate, this method also demonstrates the versatility of manganese catalysts in facilitating selective C-N bond formation. This study presents the first manganese-catalyzed synthesis of formanilides via the -formylation of anilines using (COOH)·2HO, providing a range of formanilides in moderate to excellent yields.