Homogeneous benzoylation of cellulose in 1-allyl-3-methylimidazolium chloride: Hammett correlation, mechanism and regioselectivity

	Homogeneous benzoylation of cellulose in 1-allyl-3-methylimidazolium chloride: Hammett correlation, mechanism and regioselectivity
	Chen, Weiwei 1,2; Feng, Ye 1,2; Zhang, Mei 3; Wu, Jin 1; Zhang, Jinming 1,2; Gao, Xia 3; He, Jiasong 1; Zhang, Jun 1
刊名	RSC ADVANCES
	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.