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Base-catalyzed aryl halide isomerization enables the 4-selective substitution of 3-bromopyridines.

ABSTRACT: The base-catalyzed isomerization of simple aryl halides is presented and utilized to achieve the 4-selective etherification, hydroxylation and amination of 3-bromopyridines. Mechanistic studies support isomerization of 3-bromopyridines to 4-bromopyridines proceeds via pyridyne intermediates and that 4-substitution selectivity is driven by a facile aromatic substitution reaction. Useful features of a tandem aryl halide isomerization/selective interception approach to aromatic functionalization are demonstrated. Example benefits include the use of readily available and stable 3-bromopyridines in place of less available and stable 4-halogenated congeners and the ability to converge mixtures of 3- and 5-bromopyridines to a single 4-substituted product.

SUBMITTER: Puleo TR

PROVIDER: S-EPMC8162412 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Base-catalyzed aryl halide isomerization enables the 4-selective substitution of 3-bromopyridines.

Puleo Thomas R TR Bandar Jeffrey S JS

Chemical science 20200909 38

The base-catalyzed isomerization of simple aryl halides is presented and utilized to achieve the 4-selective etherification, hydroxylation and amination of 3-bromopyridines. Mechanistic studies support isomerization of 3-bromopyridines to 4-bromopyridines proceeds <i>via</i> pyridyne intermediates and that 4-substitution selectivity is driven by a facile aromatic substitution reaction. Useful features of a tandem aryl halide isomerization/selective interception approach to aromatic functionaliza ...[more]

PMID: 34094310

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