Cycloadditions of Aryl??Substituted 1, 2, 4??Triazines with 2??Cyclopropylidene??1, 3??dimethylimidazolidine–Zwitterions as Discrete Intermediates

M Ernd, M Heuschmann, H Zipse

Index: Ernd, Michael; Heuschmann, Manfred; Zipse, Hendrik Helvetica Chimica Acta, 2005 , vol. 88, # 6 p. 1491 - 1518

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Citation Number: 24

Abstract

Abstract Cycloadditions of 2-cyclopropylidene-1, 3-dimethylimidazolidine (1), a strong, electron-rich C-nucleophile, with a variety of aryl-substituted 1, 2, 4-triazines occur at temperatures between− 100 and+ 100, depending on the substitution pattern. At low temperatures, zwitterions, formed by nucleophilic attack of 1 on the triazines, could be detected spectroscopically and, in some cases, isolated. Two types of zwitterions were ...