Pd-PEPPSI type complexes bearing unsymmetrical NHC ligand with phenyl-substituted backbone: Highly efficient catalysts for Heck-Mizoroki and Suzuki-Miyaura cross-coupling reactions

Korukcu M., Can S.

APPLIED ORGANOMETALLIC CHEMISTRY, cilt.37, sa.5, 2023 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 37 Sayı: 5
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1002/aoc.7057
  • Dergi Adı: APPLIED ORGANOMETALLIC CHEMISTRY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, BIOSIS, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Metadex, DIALNET, Civil Engineering Abstracts
  • Anahtar Kelimeler: N-heterocyclic carbene, N-heterocyclic carbene-palladium(II) complexes, Pd-PEPPSI complexes, Heck-Mizoroki reaction, Suzuki-Miyaura reaction, HETEROCYCLIC CARBENE COMPLEXES, MIXED AQUEOUS-MEDIUM, DIRECT ARYLATION, AIR, PRECATALYST, PRECURSORS, REARRANGEMENTS, TEMPERATURE, CONVENIENT, REACTIVITY
  • Bursa Uludağ Üniversitesi Adresli: Evet

Özet

A series of air-stable NHC-Pd-PEPPSI-type complexes bearing unsymmetrical NHC ligand, with a phenyl group in its backbone, were synthesized in excellent yields (82%-94%). Air and moisture-stable complexes were characterized by using H-1 NMR, C-13 NMR, FT-IR spectroscopy, and HRMS techniques. Single-crystal X-ray diffraction method was used to determine the crystal and molecular structure of the complexes. The molecular structure adopts slightly distorted square planar geometry around the metal centre and was refined as an inversion twin. The complexes were screened for their catalytic activities in Heck-Mizoroki and Suzuki-Miyaura cross-coupling reactions. Heck-Mizoroki reaction between the various aryl/hetaryl bromides and styrenes occurred in good to excellent yields in DMF in the presence of NaOAc as a base with low catalyst loadings (0.5%). The reactions also occur in aqueous media (DMF-H2O) in high yields. The Suzuki-Miyaura reaction between various aryl/hetaryl bromides and phenylboronic acids came off in excellent yields in DMF-H2O in the presence of K2CO3 as a base with low catalyst loadings (0.1%) at room temperature.