Reduced-Phenalenyl-Based Molecule as a Super Electron Donor for Radical-Mediated C-N Coupling Catalysis at Room Temperature

J Am Chem Soc. 2022 Dec 14;144(49):22611-22621. doi: 10.1021/jacs.2c09225. Epub 2022 Nov 30.

Abstract

We demonstrate that an in situ generated di-reduced phenalenyl (PLY) species accumulates sufficiently high energy and acts as a super electron donor to generate aryl radicals from aryl halides to accomplish Buchwald-Hartwig-type C-N cross-coupling reactions at room temperature. This catalytic protocol does not require any external stimuli such as heat, light, or cathodic current. This protocol shows a wide variety of substrate scope covering different genres of aryl and heteroaryl halides with various aromatic as well as aliphatic amines and late-stage functionalization of the well-known natural products. The control experiments, along with extensive density functional theory (DFT) calculations, unveil that the aryl radical is generated by a single electron transfer from the di-reduced PLY to the aryl halide substrate. The aryl radical acts as an electrophile and binds with amine, leading to the chemically driven radical-mediated C-N cross-coupling under transition-metal-free conditions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amines
  • Catalysis
  • Electron Transport
  • Electrons*
  • Temperature
  • Transition Elements*

Substances

  • Transition Elements
  • Amines