Characteristic reactivity of 3-acetamido-5-acetylfuran under oxidation conditions

Abstract

Abstract Chitin is an abundant nitrogen-containing biomass and a major derivative is 3-acetamido-5-acetylfuran (3A5AF). The oxidation of 3A5AF could produce 3-acetamido-5-carboxyfuran (3A5CF), which is a promising monomer for producing nitrogen-containing polymers. However, the conversion of 3A5AF into 3A5CF is actually difficult. The present study clarifies the characteristic reactivity of 3A5AF under typical oxidation reaction conditions. Specifically, corresponding benzene derivatives or acetylfuran are transformed into carboxylic acids, but 3A5AF cannot. Then, density functional theory calculations indicate that 3A5AF facilitates the radical addition reaction on the furan ring instead of the oxidation of the C-acetyl group. In addition to the low aromaticity of furan, the acetamido group stabilizes the radical adduct by orbital interactions. Finally, we provide a potential methodology to decrease the reactivity of the furan ring in 3A5AF.