高等学校化学学报

高等学校化学学报 ›› 1994, Vol. 15 ›› Issue (5): 685.

• 论文 • 上一篇    下一篇

2,5-二叔丁基对二甲氧基苯的去叔丁基反应的研究

龚跃法1, 赵成学1, 蒋锡夔2   

  1. 1. 华中理工大学化学系, 武汉, 430074;
    2. 中国科学院上海有机化学研究所
  • 收稿日期:1993-05-27 修回日期:1994-01-25 出版日期:1994-05-24 发布日期:1994-05-24
  • 通讯作者: 龚跃法,男,30岁,博士,副教授
  • 作者简介:龚跃法,男,30岁,博士,副教授
  • 基金资助:

    国家自然科学基金

A Mechanistic Study of the De-t-butylation Reaction of 2,5-Di-t-butyl-p-dimethoxybenzene in Acid Systems

GONG Yue-Fa1, ZHAO Cheng-Xue1, JIANG Xi-Kui2   

  1. 1. Department of Chemistry, Huazhoug University of Science and Technology, Wuhan, 430074;
    2. Shanghai Institute of Organic Chemistry, Academia Sinica, Shanghai
  • Received:1993-05-27 Revised:1994-01-25 Online:1994-05-24 Published:1994-05-24

PDF (PC)

摘要： 2,5-二叔丁基对二甲氧基苯(1)在CF3CO2H,n-C3F7CO2H或AlCl3-CH2Cl2体系中易发生去叔丁基化反应,而在强质子酸HI(aq).HBF4或CCl3CO2H中不发生此反应。在前一类体系中,都可在反应过程中观察到较强的阳离子基1+·的EPR信号,而在后一类体系中则无此信号。动力学测定表明,受物1与三氟乙酸的反应表现为三级动力学,其中1为二级,CF3CO2H为一级。这些结果揭示了去叔丁基化反应与离子自由基的形成有着内在的联系。

关键词: 去叔丁基化反应, 单电子转移, 全氟羧酸, 取代苯阳离子自由基

Abstract: We have observed that the debutylation reaction can readily occur when 2,5-di-tbutyl-p-dimethoxybenzene (1) was mixed with perfluorocarboxylic acids or with AlCl3CH2Cl2 system,but did not occur with aqueous HI or HBF4 or absolute trichloroacetic acid.EPR observation shows that radical intermediates were generated in the former systems,but not in the latter case.Kinetic study indicates that the reaction of substrate 1 with trifluoroacetic acid behaves third-order kinetics,second in 1 and first in the acid.All the results reveal that an intrinsic relation may exist between the debutylation and the formation of the radical intermediates.

Key words: De-t-butylation, Single electron transfer, Perfluorocarboxylic acid, Substituted benzene radical cation

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