Modifications to the Aryl Group of dppf-Ligated Ni σ-Aryl Precatalysts: Impact on Speciation and Catalytic Activity in Suzuki-Miyaura Coupling Reactions

Megan Mohadjer Beromi, Gourab Banerjee, Gary W. Brudvig, David J. Charboneau, Nilay Hazari, Hannah M.C. Lant, Brandon Q. Mercado

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

There is currently significant interest in the development of efficient nickel precatalysts for cross-coupling. In this work, 14 nickel(II) precatalysts of the form (dppf)Ni(aryl)(X) (dppf = 1,1′-bis(diphenylphosphino)ferrocene, X = Cl, Br) were synthesized. In particular, both the electronic and steric properties of the aryl group were modified to understand how this affects precatalyst activation. Using EPR spectroscopy, it was demonstrated that the amount of off-cycle nickel(I) species which are formed via comproportionation during precatalyst activation varies depending on the nature of the aryl group. For example, sterically bulky aryl groups reduce comproportionation. Additionally, the catalytic activity of the family of precatalysts was evaluated in five different Suzuki-Miyaura coupling reactions. The results from these catalytic studies provide information about how precatalyst structure affects catalytic efficiency, which may be useful for the rational design of improved nickel precatalysts for cross-coupling.

Original languageEnglish
Pages (from-to)3943-3955
Number of pages13
JournalOrganometallics
Volume37
Issue number21
DOIs
Publication statusPublished - Nov 12 2018

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ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

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