open access

https://hdl.handle.net/2115/87489

Effect of Lewis acid on catalytic dehydration of a chitin-derived sugar alcohol

英語

2-Acetamide-2-deoxyisosorbide

2020-12

Elsevier

Molecular Catalysis

498

111282

Chitin is an abundant marine biomass consisting of N-acetylglucosamine (NAG) units. NAG is a source for 2-acetamide-2-deoxyisosorbide (ADI), a condensed five-membered ring compound potentially useful for producing nitrogen-containing polymers. The synthetic route of ADI from NAG consists of hydrogenation of NAG to 2-acetamide-2-deoxysorbitol (ADS) by a supported metal catalyst and subsequent dehydration reaction by a BrOnsted acid catalyst. However, the dehydration step has remained a challenge due to low reactivity of the substrate and low selectivity. Here, we report a combination of BrOnsted acid and Lewis acid catalysts for accelerating the ADS dehydration. The additional use of a catalytic amount of ytterbium triflate in the ADS dehydration by trifluoromethanesulfonic acid catalyst shortens the reaction time by one third and moreover increases the yield of ADI by changing regio-selectivity of the reaction. Mechanistic roles of the ytterbium complex are discussed based on the experimental evidences and density functional theory calculations.

学術雑誌論文

Accepted Manuscript

Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

© 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/

2468-8231