Palladium-PEPPSI complexes: A robust and versatile catalyst system for the C-H arylation of heteroarenes
Küçük Resim Yok
Tarih
2026
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, the catalytic activities of newly synthesized Pd-PEPPSI complexes, derived from benzimidazole ligands functionalized with phthalimide groups were investigated in the arylation reactions of heteroaromatic ketones. The covalently attached phthalimide unit on the benzimidazole ring significantly modified the electronic and steric properties of the NHC ligands, thereby enhancing the catalytic performance of the complexes. The synthesized Pd-NHC complexes were characterized by 1H and 13C NMR, FT-IR spectroscopy, and melting point determination. For catalytic applications, 2-acetylfuran and 2-acetylthiophene were selected as model substrates, and their cross-coupling (arylation) reactions with various aryl halides were carried out under an inert atmosphere (argon) using Potassium acetate (KOAc) as base and Dimethylacetamide (DMAc) as a solvent. Reaction parameters such as temperature and time were optimized. The Pd-PEPPSI complexes exhibited high conversion rates and excellent selectivity even at low catalyst loadings, predominantly yielding C5-arylated products. The electron-donating nature and conjugation effects of the heteroatoms (S and O) in the aromatic rings of 2-acetylthiophene and 2-acetylfuran were evaluated in terms of their interaction with the Pd center and their influence on substrate activation. Additionally, the position of the phthalimide group and the nature of substituents on the benzimidazole ring were comparatively assessed for their impact on catalytic performance. Overall, the results demonstrated that 1-(phthalimide)benzimidazole-based Pd-NHC complexes act as highly efficient, stable, and reusable catalysts for C-C bond-forming reactions, especially involving heteroaromatic substrates. Furthermore, the synthesized N-phthalimido benzimidazoles can be converted into various salts via reaction with different aryl or alkyl halides, potentially allowing for the synthesis of other metal-NHC complexes with different transition metals. Such derivatives may be explored for applications in catalysis, as well as in antimicrobial or anticancer research. These findings support the potential of these complexes in advanced organic synthesis and pharmaceutical chemistry.
Açıklama
Anahtar Kelimeler
CH-Arylation, Carben, Pd-PEPPSI, Synthesis
Kaynak
Journal of Molecular Structure
WoS Q Değeri
Q2
Scopus Q Değeri
Cilt
1363
