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, sa.10, ss.1382-1391, 2017 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: Sayı: 10
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1002/ejic.201601452
  • Dergi Adı: EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.1382-1391
  • Anahtar Kelimeler: Carbenes, Benzimidazolium salts, Palladium, Heterocycles, Substituted thiophenes, C-H ARYLATION, HETEROCYCLIC CARBENE COMPLEXES, ROOM-TEMPERATURE, COUPLING REACTIONS, BENZOFURAN DERIVATIVES, BENZIMIDAZOLIUM SALTS, MONO-CARBENE, HETEROARENES, INHIBITORS, LIGANDS
  • İnönü Üniversitesi Adresli: Evet

Özet

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.