tert-Butylation of Pyridines, Quinolines, and Isoquinolines by tert-Butylmercury Halides

Glen A. Russell, Rajine Rajaratnam, Lijuan Wang, Bing Zhi Shi, Byeong Hyu Kim, Ching Fa Yao*

*此作品的通信作者

研究成果: 雜誌貢獻期刊論文同行評審

24 引文 斯高帕斯(Scopus)

摘要

Photolysis of tert-butylmercury halides with pyridinium or quinolinium salts leads to alkylation via the intermediacy of adduct radical cations. With simple pyridines or the 2-adducts from quinolines, the radical cations readily lose a proton to form a substituted pyridinyl radical which is easily oxidized by the alkylmercury halide. Addition of t-Bu· at the 4-position of the quinolinium ions, the 1-position of the isoquinolinium ions, or the 9-position of the acridinium ions, yields in the presence of KI the dihydro derivatives formed via electron transfer to the adduct radical cation from I or its ate-complex with the tert-butylmercury halide. A similar reductive alkylation is observed for the radical cations formed by the addition of t-Bu· to the β-position of the 4-vinylpyridinium ion or to the N-methylated cations derived from pyridine-3,4-dicarboximide, acridine, quinaldine, or isoquinoline. Competition between substitutive (oxidative) and additive (reductive) alkylation reflects the ease of proton loss from the intermediate adduct radical cation. Because of reversibility in adduct formation and variable rates of deprotonation of the adducts, yields of substitutive alkylation products are often not a true measure of the selectivity in the initial radical addition step. 4-tert-Butyl-l,4-dihydro-2-methylquinoline can be isolated from the photolysis of quinaldine with t-BuHgCl in the presence of KI/PTSA, methylated at C-3 by methyl iodide during the tert-butylation reaction, reduced by NaBH4 upon workup, or oxidized to the quinoline at long reaction times. 4-tert-Butyl-1,4-dihydroquinoline reacts rapidly in the presence of PTSA and t-BuHgCl to form 2,4-di-tert-butyl-1,2,3,4-tetrahydroquinoline while 4-tert-butyl-2-chloro-1,4-dihydroquinoline is readily hydrolyzed to form the amide. Although 1-tert·;-butyl-1,2-dihydro-3-methylisoquinoline is isolable, 1-tert-butyl-1,2-dihydroisoquinoline reacts via the iminium ion to form 1,3-di-tert-butyltetrahydroisoquinoline and the de-tert-butylated product 3-;tert-butyl-3,4-dihydroisoquinoline. De-tert-butylation with aromatization is also observed upon photolysis of 4-tert-butyl-3,4-dihydro-2,3-dimethylquinoline with t-BuHgCl.

原文英語
頁(從 - 到)10596-10604
頁數9
期刊Journal of the American Chemical Society
115
發行號23
DOIs
出版狀態已發佈 - 1993 十一月 1
對外發佈

ASJC Scopus subject areas

  • 催化
  • 化學 (全部)
  • 生物化學
  • 膠體和表面化學

指紋

深入研究「tert-Butylation of Pyridines, Quinolines, and Isoquinolines by tert-Butylmercury Halides」主題。共同形成了獨特的指紋。

引用此