Homogeneous benzoylation of cellulose in 1-allyl-3-methylimidazolium chloride: Hammett correlation, mechanism and regioselectivity | |
Chen, Weiwei1,2; Feng, Ye1,2; Zhang, Mei3; Wu, Jin1; Zhang, Jinming1,2; Gao, Xia3; He, Jiasong1; Zhang, Jun1 | |
刊名 | RSC ADVANCES
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2015 | |
卷号 | 5期号:72页码:58536-58542 |
英文摘要 | Homogeneous benzoylation of cellulose with a series of substituted benzoyl chlorides, in which substituents varied from electron donating to electron withdrawing groups, was investigated in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). The electronic effect of substituents had a considerable effect on the reaction. A plot of Hammett parameters of substituents vs. degree of substitution (DS) of resultant cellulose esters exhibited a V-shaped graph: a negative slope for negative Hammett parameters, and a positive slope for positive Hammett parameters. Such a Hammett plot indicated the mechanism of cellulose benzoylation: the reaction underwent a unimolecular ionization mechanism with a carbocationic intermediate when benzoyl chlorides were with electron-donating substituents, and a bimolecular addition-elimination mechanism with a tetrahedral intermediate when benzoyl chlorides were with electron-withdrawing substituents. In addition, C-13-NMR analysis showed that most of the substituted benzoyl chlorides exclusively preferred the primary hydroxyl at the C-6 position. This unusually high regioselectivity was attributed to the synergistic effect of appropriate reaction rate, moderate steric effect and reaction mechanism of benzoylation. |
收录类别 | SCI |
语种 | 英语 |
公开日期 | 2015-10-27 |
内容类型 | 期刊论文 |
源URL | [http://ir.iccas.ac.cn/handle/121111/27846] ![]() |
专题 | 化学研究所_工程塑料实验室 |
作者单位 | 1.Chinese Acad Sci, Beijing Natl Lab Mol Sci, CAS Key Lab Engn Plast, Inst Chem, Beijing 100190, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100039, Peoples R China 3.Beijing Ctr Phys & Chem Anal, Beijing Key Lab Organ Mat Testing Technol & Qual, Beijing 100089, Peoples R China |
推荐引用方式 GB/T 7714 | Chen, Weiwei,Feng, Ye,Zhang, Mei,et al. Homogeneous benzoylation of cellulose in 1-allyl-3-methylimidazolium chloride: Hammett correlation, mechanism and regioselectivity[J]. RSC ADVANCES,2015,5(72):58536-58542. |
APA | Chen, Weiwei.,Feng, Ye.,Zhang, Mei.,Wu, Jin.,Zhang, Jinming.,...&Zhang, Jun.(2015).Homogeneous benzoylation of cellulose in 1-allyl-3-methylimidazolium chloride: Hammett correlation, mechanism and regioselectivity.RSC ADVANCES,5(72),58536-58542. |
MLA | Chen, Weiwei,et al."Homogeneous benzoylation of cellulose in 1-allyl-3-methylimidazolium chloride: Hammett correlation, mechanism and regioselectivity".RSC ADVANCES 5.72(2015):58536-58542. |
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