datasheet1_Selective Utilization of N-acetyl Groups in Chitin for Transamidation of Amines.pdf

The selective transformation of chitin into various renewable N-containing chemicals and medicines has attracted increasing attention. However, the N-acetyl groups in chitin construct strong hydrogen bond networks, which restricts its depolymerization and transformation. The selective conversion of robust chitin commonly requires considerable base catalysts to remove the N-acetyl group as a byproduct in advance, which is non-compliance with the principle of atomic economy. Herein, for the first time we demonstrate a novel approach to achieve the selective utilization of the N-acetyl group in chitin for transamidation of chitin with amines. A series of amine derivatives, mainly including aliphatic amine, cyclic amine and functionalized aromatic amine, could be selectively converted into the corresponding amide products frequently found in pharmaceuticals. Furthermore, the solid residue after removing the acetyl group (denoted as De-chitin) with the sufficient exposure of -NH2 groups as a solid base catalyst shows excellent performance in the aldol condensation reaction of furfural and acetone to produce fuel precursors. Our process provides a strategy that exploiting every functional group adequately in substrates to obtain value-added chemicals.

将甲壳素（chitin）选择性转化为各类可再生含氮化学品与药物的研究，正受到日益广泛的关注。然而，甲壳素中的N-乙酰基（N-acetyl group）会形成强氢键网络，限制其解聚与转化进程。常规实现稳定甲壳素的选择性转化，通常需要使用大量碱性催化剂预先将N-乙酰基作为副产物脱除，该过程不符合原子经济性（atomic economy）原则。本研究首次报道了一种全新策略，可实现甲壳素中N-乙酰基的选择性利用，用于甲壳素与胺类的转酰胺化（transamidation）反应。一系列胺类衍生物，主要涵盖脂肪胺（aliphatic amine）、环胺（cyclic amine）与功能化芳香胺（functionalized aromatic amine），可经选择性转化得到对应酰胺产物，这类产物常见于药物分子中。此外，脱除乙酰基后的固体残渣（记为De-chitin），因表面充分暴露氨基（-NH2）而可作为固体碱性催化剂，在糠醛（furfural）与丙酮的羟醛缩合制备燃料前驱体（fuel precursors）的反应中展现出优异的催化性能。本工艺提供了一种充分利用底物中所有官能团以获取高附加值化学品的策略。