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Direct evidence on nucleophilic reactivity of secondary anilines towards an aminium radical
No full textOxidatively Activated Aromatic Substitutions. A Problem of Identification of Electronic Nature of the Reacive Species
No full textRadical anions of nitrobenzothiazoles: EPR study of conjugative properties of benzothiazolyl systems
No full textRadical anions of nitrobenzothiazoles. II. EPR study of free radical anions and ion pairs
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Aminium hexachloroantimonates salts as latent sources of antimony pentacloride in pinacolic rearrangement of vicinal diols
No full textRearrangements of various vicinal diols (1a–f) induced by
hexachloroantimonate aminium salts A or B were found to
occur in a similar manner when antimony pentachloride was
used instead of aminium salts. Antimony pentachloride is
proposed as the active catalytic species, possibly deriving from the oxidation of the hexachloroantimonate anion SbCl6–
by the aminium counterpart
Aminium Salts-Induced Dimerization of alpha-Methylstyrene and 1-Aryl-1-Phenylethylenes. Solvent Effect
No full textThe aminium salts-induced dimerization of alfa-methylstyrene lb gives rise,
depending on the solvent employed, to high yields of 1,3,3-trimethyl-1-phenylindane
2b, or 2,4-diphenyl-4-methyl-l-pentene 6b. Several 1-aryl-l-phenylethylenes la,c-e
afford, instead, cyclodimers 2a,c-e, or 2,5-diaryl-2,5-diphenyltetrahydrofuran
derivatives 3a,c-e
Oxidative activation in aromatic substitutions. Reactions of N,N-dimethylanilines with secondary Anilines promoted by thallium triacetate
No full textThe reactions of N,N-dimethyl-p-anisidine (1a), N,N-dimethylaniline (1b), and N,N-dimethyl-pfluoroaniline
(1c) toward secondary anilines 2(a-d)-H in the presence of thallium triacetate
sesquihydrate have been studied as representative of a novel oxidatively activated aromatic
substitution affording 1,4-benzenediamine derivatives 3a-d. All of the substrates considered gave
substitution with diphenylamine (2d-H). However, with anilines 2b,c-H, only 1a underwent
substitution, and substrates 1b,c were practically unreactive. The observed differences in reactivity
are well accounted for within a mechanistic framework wherein oxidative activation of both the
substrate and the secondary aniline is regarded as alternatively (or simultaneously) possible,
depending on the redox characteristics of the reactants. For instance, it can be stated, beyond any
reasonable doubt, that reactions of 1a with 2b,c-H proceed via nucleophilic attack of the latter on
1a+¥, and that the reaction of 1a-c with 2d-H must involve the diphenylamino radical 2d¥
Ciclodimerizzazione chemo-diastereoselettiva di 1-aril-1-feniletileni indotta da sali di amminio: effetto solvente
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