PEPPSI-Type Palladium-NHC Complexes: Synthesis, Characterization, and Catalytic Activity in the Direct C5-Arylation of 2-Substituted Thiophene Derivatives with Aryl Halides


KALOĞLU M. , ÖZDEMİR İ. , DORCET V., BRUNEAU C., DOUCET H.

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, no.10, pp.1382-1391, 2017 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: Issue: 10
  • Publication Date: 2017
  • Doi Number: 10.1002/ejic.201601452
  • Title of Journal : EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
  • Page Numbers: pp.1382-1391

Abstract

Six benzimidazolium salts, having two nitrogen atoms substituted by various alkyl groups, have been synthesized in high yields. The benzimidazolium salts readily converted into the corresponding PEPPSI-type palladium-NHC complexes (PEPPSI = pyridine-enhanced precatalyst preparation, stabilization, and initiation). The structures of all compounds have been characterized by H-1 NMR, C-13 NMR, and IR spectroscopy, as well as elemental analysis techniques, which support the proposed structures. The molecular structure of one complex has been determined by single-crystal X-ray diffraction. The catalytic activity of the PEPPSI-type palladium-NHC complexes has been evaluated with respect to the direct C5-arylation of 2-substituted thiophene derivatives with various aryl halides. This arylation occurs efficiently and selectively at the C5-position of 2-substituted thiophene derivatives.