Synthesis 2012; 44(21): 3371-3377
DOI: 10.1055/s-0032-1316775
paper
© Georg Thieme Verlag Stuttgart · New York

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

Joanne M. O’Connell, Eoin Moriarty, Fawaz Aldabbagh*
  • School of Chemistry, National University of Ireland Galway, University Road, Galway, Ireland   Fax: +353(91)495576   Email: Fawaz.Aldabbagh@nuigalway.ie
Further Information

Publication History

Received: 26 July 2012

Accepted after revision: 20 August 2012

Publication Date:
31 August 2012 (eFirst)

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.

Supporting Information

 
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