高等学校化学学报 ›› 2023, Vol. 44 ›› Issue (6): 20220701.doi: 10.7503/cjcu20220701

• 有机化学 • 上一篇    下一篇

芴羟甲基化合成9-芴甲醇过程中脱水产物生成的影响因素及机理

刘俊丽1,2, 叶翠平1,2(), 郭美鑫1, 李文英3   

  1. 1.太原理工大学环境科学与工程学院, 晋中 030600
    2.山西浙大新材料与化工研究院, 太原 030000
    3.太原理工大学省部共建煤基能源清洁高效利用国家重点实验室, 太原 030024
  • 收稿日期:2022-11-05 出版日期:2023-06-10 发布日期:2023-02-09
  • 通讯作者: 叶翠平 E-mail:yecuiping@tyut.edu.cn
  • 基金资助:
    国家自然科学基金(21776192);山西浙大新材料与化工研究院研发项目(2021SX-FR003)

Influencing Factors and Mechanism of Dehydration Product Formation During Hydroxylmethylation of Fluorene to 9-Fluorenylmethanol

LIU Junli1,2, YE Cuiping1,2(), GUO Meixin1, LI Wenying3   

  1. 1.College of Environmental Science and Engineering,Taiyuan University of Technology,Jinzhong 030600,China
    2.Shanxi?Zheda Institute of Advanced Materials and Chemical Engineering,Taiyuan 030000,China
    3.State Key;Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan 030024,China
  • Received:2022-11-05 Online:2023-06-10 Published:2023-02-09
  • Contact: YE Cuiping E-mail:yecuiping@tyut.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21776192);the Research and Development Project of Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering, China(2021SX-FR003)

摘要:

以多聚甲醛为羟甲基化试剂, 在碱催化下芴一步生成9-芴甲醇过程极易发生单分子共轭碱消除, 脱水生成富烯化合物, 导致9-芴甲醇的选择性下降. 为实现对该过程的调控, 本文考察了温度、 碱的种类、 乙醇和多聚甲醛的添加等对9-芴甲醇脱水反应的影响, 并结合动力学计算和同位素示踪, 推测了芴羟甲基化合成 9-芴甲醇过程中副产物生成的机理. 结果表明, 升高温度、 增加碱性和添加甲醛有利于脱水反应发生. 乙醇通过氢键作用促进脱水反应, 添加量大时会导致芴负离子和9-芴甲醇负离子发生质子化作用. 中间体可能会发生分子内氢传递或者夺取芴和9-芴甲醇的9位氢, 促进脱水反应发生.

关键词: 脱水反应, 同位素示踪, 分子内氢传递, 分子间夺氢

Abstract:

During one-step synthesis process of 9-fluorenylmethanol with paraformaldehyde as hydroxymethylation reagent, 9-fluorenylmethanol is easy to undergo base-catalyzed β-elimination(E1cb) to yield dibenzofulvene, and the selectivity of 9-fluorenylmethanol decreased. To achieve the process of regulation and control, the factors affecting the dehydration of 9-fluorenylmethanol, such as temperature, the types of alkali and ethanol and paraformaldehyde were investigated. The mechanism of by-product formation in the process of hydroxymethylation of fluorene to form 9-fluorenylmethanol was speculated according to the experimental results, kinetic calculation and isotope tracing. The results showed that increasing the temperature and alkalinity, and adding formaldehyde promoted the dehydration reaction. Ethanol promotes dehydration reaction through hydrogen bonding, and a large amount of ethanol would lead to the internal protonation of fluorenyl anion and 9-fluorenylmethanol anion. The intermediate may have the behavior of intramolecular hydrogen transfer or intermolecular hydrogen capture from fluorene and 9-fluorenylmethanol, facilitating dehydration reactions.

Key words: Dehydration reaction, Isotope tracing, Intramolecular hydrogen transfer, Intermolecular hydrogen capture

中图分类号: 

TrendMD: