Activation of Electrophilicity of Stable Y-Delocalized Carbamate Cations in Intramolecular Aromatic Substitution Reaction: Evidence for Formation of Diprotonated …

…, K Kawamoto, H Sugimoto, S Nakamura…

Index: Nakamura, Satoshi; Sugimoto, Hiromichi; Ohwada, Tomohiko Journal of Organic Chemistry, 2008 ,  vol. 73,  # 11  p. 4219 - 4224

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Citation Number: 10

Abstract

Although cations with three heteroatoms, such as monoprotonated guanidine and urea, are stabilized by Y-shaped conjugation and such Y-conjugated cations are sufficiently basic to be further protonated (or protosolvated) to dications in strongly acid media, only O- monoprotonated species have been detected in the case of carbamates even in magic acid. We found that the trifluoromethanesulfonic acid-catalyzed cyclization of ...