Nucleophilic substitution inO-phenyldibenzofuranium and 10-phenylxanthonium cations
作者:T. P. Tolstaya、M. S. Bobyleva、A. N. Vanchikov、G. V. Kovalysheva、N. S. Kulikov、D. A. Tsariev
DOI:10.1007/bf02495215
日期:1997.4
Reactions of O-phenyldibenzofuranium tetrafluoroborate with nucleophiles (OH-, NO2-, AcO-) in aqueous media follow the SNAr-mechanism and involve dehydroarenes. In DMSO, this salt smoothly reacts with NO2- and I- with predominant opening of the furan ring. 10-Phenylxanthonium tetrafluoroborate readily arylates the NO2- ion in water (at the N and O atoms), mainly with predominant opening of the central ring, and is completely decomposed even with weak bases (N H2OH, 2,4-dinitrophenylhydrazine). The Baeyer-Villiger oxidation of this salt affords xanthone and 2-phenoxybenzoic acid.