Access to Aromatic Ring-Fused Benzimidazoles Using Photochemical Substitutions of the Benzimidazol-2-yl Radical

Joanne M. O’Connell; Eoin Moriarty; Fawaz Aldabbagh

doi:10.1055/s-0032-1316775

Synthesis, Table of Contents

Synthesis 2012; 44(21): 3371-3377
DOI: 10.1055/s-0032-1316775

paper

Access to Aromatic Ring-Fused Benzimidazoles Using Photochemical Substitutions of the Benzimidazol-2-yl Radical

Joanne M. O’Connell

School of Chemistry, National University of Ireland Galway, University Road, Galway, Ireland Fax: +353(91)495576 Email: Fawaz.Aldabbagh@nuigalway.ie

,

Eoin Moriarty

School of Chemistry, National University of Ireland Galway, University Road, Galway, Ireland Fax: +353(91)495576 Email: Fawaz.Aldabbagh@nuigalway.ie

,

Fawaz Aldabbagh*

School of Chemistry, National University of Ireland Galway, University Road, Galway, Ireland Fax: +353(91)495576 Email: Fawaz.Aldabbagh@nuigalway.ie

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Abstract

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Abstract

Photochemical five-, six-, and seven-membered cyclizations from 2-iodo-1-(ω-arylalkyl)-1H-benzimidazoles are described. This method of producing aromatic ring-fused benzimidazoles is significantly more efficient than literature radical protocols using chemical initiators, although 2-iodo-1-(ω-pyridin-2-ylalkyl)-1H-benzimidazoles preferentially undergo a nucleophilic ipso-substitution onto the benzimidazole-2-position.

Key words

cyclization - diazoles - heterocycles - nucleophilic aromatic substitution - radical reaction

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References

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