Matthewman Emma L, Sperry Jonathan, Weber Cameron C
School of Chemical Sciences, University of Auckland, 23 Symonds Street, Auckland, 1010, New Zealand.
MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand.
ChemistryOpen. 2025 Sep;14(9):e202500094. doi: 10.1002/open.202500094. Epub 2025 Feb 25.
The transformation of chitin and its monomer N-acetylglucosamine (NAG) to high-value organonitrogen chemicals has attracted increasing interest, with 3-acetamido-5-acetylfuran (3A5AF) proposed as a versatile platform chemical. The preparation of 3A5AF from NAG has relied on high boiling organic solvents, ionic liquids (ILs) or deep eutectic solvents (DES). While these methods have met with some success, the isolation of 3A5AF and recycling of the solvent remains problematic for non-IL methods whereas most IL methods utilize inherently expensive aprotic ILs with substantial environmental footprints. This study details the preparation of 3A5AF in more cost-effective chloride-based protic ILs (PILs) with lower synthetic footprints than conventional ILs. Maximum yields of 42.5 %, 51.5 % and 57.0 % of 3A5AF were afforded in 1,8-diazabicyclo[5.4.0]undec-7-ene chloride ([DBU]Cl), tripropylammonium chloride ([TPA]Cl) and tributylammonium chloride ([TBA]Cl) respectively with 2 eq. B(OH) at 150 °C. The 3A5AF formed was readily isolated by simple solvent extraction, avoiding column chromatography, with selected systems displaying good recyclability and scalability. E-factor calculations revealed that the PIL methodology produced substantially less waste than approaches for the production of 3A5AF from molecular solvents and DES, highlighting that PILs are suitable solvents for the sustainable production of 3A5AF.
将几丁质及其单体N-乙酰葡糖胺（NAG）转化为高价值有机氮化学品已引起越来越多的关注，3-乙酰氨基-5-乙酰基呋喃（3A5AF）被提议作为一种通用的平台化学品。从NAG制备3A5AF依赖于高沸点有机溶剂、离子液体（ILs）或低共熔溶剂（DES）。虽然这些方法取得了一些成功，但对于非离子液体方法而言，3A5AF的分离和溶剂的循环利用仍然存在问题，而大多数离子液体方法使用本质上昂贵的非质子离子液体，且对环境影响较大。本研究详细介绍了在更具成本效益的氯化物基质子离子液体（PILs）中制备3A5AF的方法，其合成足迹比传统离子液体更小。在1,8-二氮杂双环[5.4.0]十一碳-7-烯氯化物（[DBU]Cl）、三丙基氯化铵（[TPA]Cl）和三丁基氯化铵（[TBA]Cl）中，分别加入2当量的B(OH)，在150℃下，3A5AF的最大产率分别为42.5%、51.5%和57.0%。通过简单的溶剂萃取即可轻松分离生成的3A5AF，无需柱色谱法，所选体系显示出良好的可回收性和可扩展性。E因子计算表明，与从分子溶剂和低共熔溶剂生产3A5AF的方法相比，质子离子液体方法产生的废物要少得多，这突出表明质子离子液体是可持续生产3A5AF的合适溶剂。
