Tandem insertion-cyclization reaction of isocyanides in the synthesis of 1,4-diaryl-1H-imidazoles : Presence of N-arylformimidate intermediate

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

47 Scopus Citations
View graph of relations

Author(s)

  • Benjamin Pooi
  • Jeongbin Lee
  • Kyujin Choi
  • Hajime Hirao
  • Soon Hyeok Hong

Detail(s)

Original languageEnglish
Pages (from-to)9231-9245
Journal / PublicationJournal of Organic Chemistry
Volume79
Issue number19
Publication statusPublished - 3 Oct 2014
Externally publishedYes

Abstract

A straightforward and high-yielding synthesis of 1,4-diaryl-1H-imidazoles is reported. 1,4-Diaryl-1H-imidazoles have been difficult to access in ambient conditions, but our method utilizes two different facets of isocyanide reactivity to achieve it. The reaction is believed to involve (1) NHC-copper-catalyzed isocyanide insertion into alcohol to form an N-arylformimidate intermediate and (2) subsequent base-promoted cycloaddition with benzyl isocyanide derivatives. There is cooperation between these two processes through the deprotonation of benzyl isocyanide by KOtBu. The deprotonation gives tert-butyl alcohol and the benzyl isocyanide anion, which are used for the first and second steps of the reaction, respectively. Various control and kinetic experiments were carried out to gain an in-depth understanding of the reaction mechanism and isocyanide reactivity. The reaction mechanism determined by density functional theory calculations was consistent with the experimental data and provided detailed explanations for the reactivity trends.

Citation Format(s)

Tandem insertion-cyclization reaction of isocyanides in the synthesis of 1,4-diaryl-1H-imidazoles : Presence of N-arylformimidate intermediate. / Pooi, Benjamin; Lee, Jeongbin; Choi, Kyujin; Hirao, Hajime; Hong, Soon Hyeok.

In: Journal of Organic Chemistry, Vol. 79, No. 19, 03.10.2014, p. 9231-9245.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal