Organonitrogen platform chemicals and pharmaceutical precursors: a perspective on sustainable chitin utilization

Chitin is an abundant biopolymer sourced from, among others, crustacean shell waste and contains biologically-fixed nitrogen. Its conversion into valuable nitrogen-containing organic compounds has gained growing interest. These compounds can serve as platform chemicals and offer a sustainable alternative to fossil-based chemical production. In this review, we discuss the general pathways for chitin valorisation, including chitin pyrolysis, deacetylation to chitosan, depolymerisation into N-acetyl chitin oligosaccharides (COSs) and N-acetylglucosamine (NAG) and subsequent conversion to furans, heterocyclic compounds, polyols, amines and amino acids. Special emphasis is placed on the recent progress in expanding the chemical space attainable from chitin-derived furan platforms, particularly focusing on the synthesis of benzenoid aromatic compounds via Diels–Alder and subsequent dehydration reactions. By highlighting these transformation pathways and the resulting high-value products, this review provides a comprehensive overview of recent developments and future opportunities for the sustainable production of nitrogen-containing compounds from chitin.