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Substitutions by nucleophilic free radicals: A new general reaction of heteroaromatic bases
Author(s) -
Minisci Francesco,
Fontana Francesca,
Vismara Elena
Publication year - 1990
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570270107
Subject(s) - chemistry , homolysis , radical , decarboxylation , reactivity (psychology) , nucleophile , nucleophilic substitution , acylation , hydrogen atom abstraction , protonation , alkylation , computational chemistry , organic chemistry , catalysis , medicine , ion , alternative medicine , pathology
The substitution of protonated heteroaromatic bases by nucleophilic carbon‐centered radicals has been developed as one of the most general reactions in the heterocyclic series; its great interest results from the fact that it reproduces most of the numerous aspects of the Friedel‐Crafts aromatic substitution, but with opposite reactivity and selectivity. The most recent developments, concerning the generation of free radicals by iodine and hydrogen abstraction and decarboxylation of carboxylic acids are particularly discussed. Some processes of high synthetic value were designed on the basis of the kinetic and thermodynamic features of all the elementary steps involved in complex but selective chain processes. New general procedures for the monosubstitution in the homolytic alkylation and acylation are reported and discussed.