Expanded scope of chitin-derived nitrogen scaffolds enabled by the 3-acetamido-5-furfurylaldehyde (3A5F) platform

The chitin-derived platform 3-acetamido-5-furfurylaldehyde (3A5F) undergoes organocatalyzed oxidative esterification with various alcohols to produce 4-acetamidofuran-2-carboxylates, enabling streamlined access to this previously unexplored chemical space. The reaction proceeds under mild conditions, using an affordable thiazolium catalyst, molecular oxygen as the oxidant, and ethyl acetate as the solvent (if necessary). Additionally, 3A5F facilitates access to a 3-acetamidobutenolide and 5-vinylfuran-3-acetamide, valuable biogenic platforms with a broad range of potential applications. All the products contain biogenic nitrogen and have been synthesized without using building blocks derived from ammonia produced via the energy-intensive Haber process.