C2-Selective Branched Alkylation of Benzimidazoles by Rhodium(I)-Catalyzed C-H Activation

J Org Chem. 2017 Sep 1;82(17):9243-9252. doi: 10.1021/acs.joc.7b01723. Epub 2017 Aug 22.

Abstract

Herein, we report a Rh(I)/bisphosphine/K3PO4 catalytic system allowing for the first time the selective branched C-H alkylation of benzimidazoles with Michael acceptors. Branched alkylation with N,N-dimethyl acrylamide was successfully applied to the alkylation of a broad range of benzimidazoles incorporating a variety of N-substituents and with both electron-rich and -poor functionality displayed at different sites of the arene. Moreover, the introduction of a quaternary carbon was achieved by alkylation with ethyl methacrylate. The method was also shown to be applicable to the C2-selective branched alkylation of azabenzimidazoles.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylation
  • Benzimidazoles / chemistry*
  • Catalysis
  • Molecular Structure
  • Organometallic Compounds / chemistry*
  • Rhodium / chemistry*

Substances

  • Benzimidazoles
  • Organometallic Compounds
  • Rhodium