Construction of Spirocyclic Pyrrolo[1,2- a]quinoxalines via Palladium-Catalyzed Hydrogenative Coupling of Phenols and Nitroarenes

J Org Chem. 2022 Dec 16;87(24):16449-16457. doi: 10.1021/acs.joc.2c02158. Epub 2022 Dec 1.

Abstract

The replacement of fossil resources with biomass resources in the construction of N-heterocycles is rapidly attracting research interest. Herein, we report palladium-catalyzed selective hydrogenative coupling of nitroarenes and phenols based on a transfer hydrogenation strategy, allowing straightforward access to spirocyclic pyrrolo- and indolo-fused quinoxalines, a class of compounds found in numerous natural alkaloids. The synthetic protocol is characterized by a broad substrate scope and the utilization of biomass-derived reactants and commercially available catalysts. In such transformations, high-pressure and explosive hydrogen are not required. This report provides a new protocol for converting biomass-derived phenols into value-added nitrogen-containing chemicals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Hydrogenation
  • Palladium* / chemistry
  • Phenols
  • Quinoxalines* / chemistry

Substances

  • Palladium
  • Quinoxalines
  • Phenols