Significant facilitation of metal-free aerobic oxidative cyclization of imines with water in synthesis of benzimidazoles

Ye Sol Lee, Yeon Ho Cho, Seungjae Lee, Jong Kwan Bin, Joonghwan Yang, Geesung Chae, Cheol-Hong Cheon

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

A simple, convenient, and environmentally benign protocol for the synthesis of benzimidazoles from ortho-phenylenediamines and aldehydes via aerobic oxidation was developed in wet organic solvents. Notably, water significantly accelerated this transformation, which allowed us to achieve this important transformation without the assistance of any metal catalysts and other co-oxidants. Mechanistic studies suggested that water acts as the nucleophilic catalyst for this transformation by the conversion of disfavored 5-endo-trig cyclization of imines to favored 5-exo-tet cyclization via tetrahedral intermediates and the subsequent aerobic oxidation of the resulting benzimidazolines affords benzimidazoles.

Original languageEnglish
Pages (from-to)532-538
Number of pages7
JournalTetrahedron
Volume71
Issue number4
DOIs
Publication statusPublished - 2015 Jan 28

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Benzimidazoles
Imines
Cyclization
Metals
Oxidation
Catalysts
Water
Oxidants
Aldehydes
Organic solvents
1,2-diaminobenzene

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Drug Discovery

Cite this

Significant facilitation of metal-free aerobic oxidative cyclization of imines with water in synthesis of benzimidazoles. / Lee, Ye Sol; Cho, Yeon Ho; Lee, Seungjae; Bin, Jong Kwan; Yang, Joonghwan; Chae, Geesung; Cheon, Cheol-Hong.

In: Tetrahedron, Vol. 71, No. 4, 28.01.2015, p. 532-538.

Research output: Contribution to journalArticle

Lee, Ye Sol ; Cho, Yeon Ho ; Lee, Seungjae ; Bin, Jong Kwan ; Yang, Joonghwan ; Chae, Geesung ; Cheon, Cheol-Hong. / Significant facilitation of metal-free aerobic oxidative cyclization of imines with water in synthesis of benzimidazoles. In: Tetrahedron. 2015 ; Vol. 71, No. 4. pp. 532-538.
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