“Transition-metal-free” synthesis of carbazoles by photostimulated reactions of 2′-halo[1,1′-biphenyl]-2-amines

J Org Chem. 2015 Jan 16;80(2):928-41. doi: 10.1021/jo5024393.

Abstract

An efficient and simple protocol for the preparation of a series of 9H-carbazoles by photostimulated SRN1 substitution reactions is presented. Substituted 9H-carbazoles were synthesized in low to excellent yields (up to 96%) through an intramolecular C–N bond formation of 2′-halo[1,1′-biphenyl]-2-amines by the photoinitiated SRN1 mechanism under mild and “transition-metal-free” conditions. The biphenylamines used as substrates were obtained with isolated yields ranging from 21% to 84% by two approaches: (A) the cross-coupling Suzuki–Miyaura reaction and (B) the radical arylation of anilines. Some key aspects of the proposed mechanism were evaluated at the B3LYP/6-311+G* level.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aniline Compounds / chemistry*
  • Biphenyl Compounds / chemistry*
  • Carbazoles / chemical synthesis*
  • Carbazoles / chemistry
  • Catalysis
  • Metals / chemistry*
  • Molecular Structure
  • Transition Elements / chemistry*

Substances

  • Aniline Compounds
  • Biphenyl Compounds
  • Carbazoles
  • Metals
  • Transition Elements
  • aniline