Insights into directing group ability in palladium-catalyzed C-H bond functionalization

J Am Chem Soc. 2008 Oct 8;130(40):13285-93. doi: 10.1021/ja8045519. Epub 2008 Sep 10.

Abstract

This paper describes a detailed investigation of factors controlling the dominance of a directing group in Pd-catalyzed ligand-directed arene acetoxylation. Mechanistic studies, involving reaction kinetics, Hammett analysis, kinetic isotope effect experiments, and the kinetic order in oxidant, have been conducted for a series of different substrates. Initial rates studies of substrates bearing different directing groups showed that these transformations are accelerated by the use of electron-withdrawing directing groups. However, in contrast, under conditions where two directing groups are in competition with one another in the same reaction flask, substrates with electron-donating directing groups react preferentially. These results are discussed in the context of the proposed mechanism for Pd-catalyzed arene acetoxylation.

Publication types

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

MeSH terms

  • Amides / chemistry
  • Carbon / chemistry*
  • Catalysis
  • Enzyme Inhibitors / chemistry
  • Hydrogen / chemistry*
  • Kinetics
  • Molecular Structure
  • Oximes / chemistry
  • Palladium / chemistry*
  • Pyridines / chemistry

Substances

  • Amides
  • Enzyme Inhibitors
  • Oximes
  • Pyridines
  • Palladium
  • Carbon
  • Hydrogen