Mechanistic Insight into Biomass Conversion to Five–membered Lactone Based on Computational and Experimental Analysis
Mechanistic Insight into Biomass Conversion to Five–membered Lactone Based on Computational and Experimental Analysis
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DOI：
10.1002/slct.201601888
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发表时间：
2017-01
期刊：
影响因子：
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通讯作者：
Sho Yamaguchi;Hikaru Deguchi;S. Kawauchi;Ken Motokura;A. Miyaji;T. Baba
中科院分区：
文献类型：
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作者：
Sho Yamaguchi;Hikaru Deguchi;S. Kawauchi;Ken Motokura;A. Miyaji;T. Baba
采用密度泛函理论（DFT）研究了1，3-二羟基丙酮（DHA）与甲醛的级联偶联反应机理。基于我们的实验结果，与之前提出的反应途径相反，我们提出了以下途径：i）DHA异构化和脱水为烯醇化物，ii）烯醇化物与甲醛之间的羟醛缩合反应，iii）形成五元环，iv）质子转移形成α-羟基-γ-丁内酯（HBL）。考虑到每个基板的热力学稳定性，使我们能够建议最有可能的途径，和过渡态模型的建设帮助我们澄清所观察到的产品选择性的起源。
We investigated the mechanism of a cascade coupling reaction between 1,3‐dihydroxyacetone (DHA) and formaldehyde using density functional theory (DFT) calculations. Based on our experimental results, and in contrast to the previously proposed reaction pathway, we propose the following pathway: i) the isomerization and dehydration of DHA to an enolate, ii) an aldol reaction between the enolate and formaldehyde, iii) the formation of a five‐membered ring, and iv) a proton transfer to form α‐hydroxy‐γ‐butyrolactone (HBL). Consideration of the thermodynamic stability of each substrate enabled us to suggest the most likely pathway, and the construction of a transition state model helped us to clarify the origin of the observed product selectivity.