Palladium-Catalyzed Cross-Coupling Reaction via C–H Activation of Furanyl and Thiofuranyl Substrates


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ŞAHİN N., ÖZDEMİR İ., Sémeril D.

Inorganics, cilt.12, sa.6, 2024 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 12 Sayı: 6
  • Basım Tarihi: 2024
  • Doi Numarası: 10.3390/inorganics12060175
  • Dergi Adı: Inorganics
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Directory of Open Access Journals
  • Anahtar Kelimeler: benzimidazolium salt, cross-coupling, C–H activation, homogeneous catalysis, palladium, styryl substituent
  • Sivas Cumhuriyet Üniversitesi Adresli: Evet

Özet

The present study explores the potential of four NHC-palladium(II) complexes derived from (Z)- or (E)-styryl-N-alkylbenzimidazolium salts, namely trans-dichloro-[(Z)-1-styryl- 3-benzyl-benzimidazol-2-yliden]pyridine palladium(II) (6), trans-dichloro-[(E)-1-styryl-3-benzyl- benzimidazol-2-yliden]pyridine palladium(II) (7), trans-dichloro-[(Z)-1-styryl-3-(3-fluorobenzyl)- benzimidazol-2-yliden]pyridine palladium(II) (8) and trans-dichloro-[(E)-1-styryl-3- (3-fluorobenzyl)-benzimidazol-2-yliden]pyridine palladium(II) (9), to be use as pre-catalysts for the cross-coupling reactions between furanyl or thiofuranyl derivatives and arylbromides via the C–H activation of the heterocycles. The structures of the four Pd(II) complexes have been elucidated through the use of multinuclear NMR, FT-IR and mass spectroscopy. Furthermore, the cis or trans conformation of the styryl substituents and the geometry of two different compounds was substantiated by single-crystal X-ray diffraction, which was carried out on organometallic species 6, 8 and 9. After the optimization of catalytic conditions, which was carried out with 1 mol% of pre-catalyst with KOAc as a base in dimethylacetamide at 120 °C for 3 h, complex 6 proved to be the most effective pre-catalyst agent, with full or quasi full conversions being observed in the cross-coupling of 4-bromoacetophenone with 2-butylfuran, 1-(2-furanyl)-ethanone, furfuryl acetate, furfural, 1-(2-thienyl)-ethanone, thenaldehyde and 2-methylthiophene.