Transition-Metal-Free Transfer Hydrogenative Cascade Reaction of Nitroarenes with Amines/Alcohols: Redox-Economical Access to Benzimidazoles

J Org Chem. 2021 Nov 5;86(21):14597-14607. doi: 10.1021/acs.joc.1c01450. Epub 2021 Oct 18.

Abstract

This report describes an efficient transition-metal-free process toward the transfer hydrogenative cascade reaction between nitroarenes and amines or alcohols. The developed redox-economical approach was realized using a combination of KOtBu and Et3SiH as reagents, which allows the synthesis of benzimidazole derivatives via σ-bond metathesis. The reaction conditions hold well over a wide range of substrates embedded with diverse functional groups to deliver the desired products in good to excellent yields. The mechanistic proposal has been depicted on the basis of a series of control experiments, mass spectroscopic evidence which is well supported by density functional theory (DFT) calculations with a feasible energy profile.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohols*
  • Amines
  • Benzimidazoles
  • Oxidation-Reduction
  • Transition Elements*

Substances

  • Alcohols
  • Amines
  • Benzimidazoles
  • Transition Elements