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HYDROPEROXIDES AS PSEUDOHALIDES - OXIDATION, OXIDATIVE ALKYLATION, ACYLATION AND ARYLATION OF ACRYLONITRILE
No full textNucleophilic character of alkyl radicals. XIV. Homolytic Î ́âaminoalkylation of protonated quinoxaline
No full textA new general reaction of wide synthetic interest, involving homolytic Î ́âaminoalkylation of quinoxaline in acidic medium, is described. Primary and secondary alkylamines, through the corresponding Nâchloroamines, and tertiary alkylamines, through the corresponding Nâoxides, are used. The mechanism of the reaction, involving intramolecular hydrogen abstraction by amino radical cations, and the unusual selectivity are discussed in terms of nucleophilic character of the alkyl radicals and of polar effects in the aromatic substitution. Copyright © 1976 Journal of Heterocyclic Chemistr
Nucleophilic character of alkyl radicals. Part 15. Selective homolytic alkylation of quinoxaline by N-chloro-amines; influence of medium acidity
No full textSelective homolytic alkylation of protonated quinoxaline has been achieved by using an alkyl derivative with N-chlorodialkylamine as radical source. The method shows great synthetic potential and can also be used for other heteroaromatic bases. A free-radical chain process involving amine radical cations is suggested to explain the clean reaction. Positional selectivity is strongly affected by the medium acidity, and a correlation between the π-electron density of mono- and di-protonated quinoxaline and the substitution orientation is found, in agreement with the nucleophilic character of the alkyl radicals
Free-radical mechanisms in the oxidation and halogenation of alkanes, alkenes and alkylbenzenes by t-BuOOH under Gif-Barton catalysis
No full textNEW SYNTHESES OF MIXED PEROXIDES UNDER GIF-BARTON OXIDATION OF ALKYLBENZENES, CONJUGATED ALKENES AND ALKANES - A FREE-RADICAL MECHANISM
No full textREDOX CATALYSIS IN FREE-RADICAL REACTIONS - NEW, SIMPLE, CONVENIENT INTRAMOLECULAR HOMOLYTIC AROMATIC SUBSTITUTIONS
No full text
Homolytic Î ́-aminoadeltalkylation of protonated quinoxaline by N-chloroamine
No full textN-chloroalkylamines in the presence of reducing metal salts and protonated quinoxaline undergoes intramolecular hydrogen abstraction to delta-aminoalkyl radicals which add to the protonated quinoxaline affording 2- and 6-delta-aminoalkylquinoxalines depending on the acidity of the medium
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