高等学校化学学报 ›› 1991, Vol. 12 ›› Issue (6): 814.

• 论文 • 上一篇    下一篇

取代苯基烷基酮与叔丁基氯化镁反应的机理研究

龚跃法, 曲延玲, 赵成学   

  1. 华中理工大学化学系, 武汉, 430074
  • 收稿日期:1990-02-17 出版日期:1991-06-24 发布日期:1991-06-24
  • 通讯作者: 赵成学

Studies on Mechanism of the Reactions of Substituted Alkyl Phenyl Ketones with t-Butylmagnesium Chloride

Gong Yue-fa, Qu Yian-ling, Zhao Cheng-xue   

  1. Department of Chemistry, Huazhong University of Science and Technlogy, Wuhan, 430074
  • Received:1990-02-17 Online:1991-06-24 Published:1991-06-24

摘要: 通过EPR技术观察到一系列典型的烷基或甲氧基取代的苯基烷基酮ArCOR(Ar=2,5-二甲基苯基(1);2,5-二甲氧基苯基(2);4-叔丁基-2,5-二甲氧基苯基(3))与t-BuMgCl反应中形成的自由基阴离子中间体[ArC(R)OMgCl]。产物分析表明,反应主要生成还原产物[ArCH(R)OH]和1,2-加成产物[ArC(R)(t-Bu)OH]。降低溶剂极性及反应温度都有利于还原产物的生成。对上述反应的可能历程作了简单讨论。

关键词: 苯基烷基酮, 格氏反应, 酮自由基阴离子, 电子顺磁共振

Abstract: We have directly observed twelve ketyl radical intermediates 4~6[ArC(R)OMgX) formed during the reactions of a series of alkyl aryl ketones 1~3(Ar: 2,5-dimethylphenyl (1); 2,5-dimethoxyphenyl(2); 4-t-butyl-2, 5-dimethoxyphenyl (3) with t-butyl magnesium chloride by means of EPRtechnique. The product analysis shows that the major products formed in the reactions of alkyl 2,5-dimethylphenyl ketones la-d (R:a, Me; b, Et; c, i-Pr; d, t-Bu) are reduction products 7 and 1,2-addition products 8. The lower polarity of the used solvent and the lower reaction temperature would favour the formation of 7. In accordance with these results, the possible mechanisms for the titled reactions are discussed.

Key words: Alkyl phenyl ketones, Grignard reactions, Ketyl radical anions, Election paramagnetic resonance (EPR)

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