New Pd-PEPPSI complexes bearing meta-cyanobenzyl-Substituted NHC: Synthesis, characterization, crystal structure and catalytic activity in direct C–H arylation of (Hetero)arenes with aryl bromides

• Published in: Journal of molecular structure 2020-04, Vol.1205, p.127608, Article 127608
• Main Authors: Türker, Ferhat, Bereket, İmran, Barut Celepci, Duygu, Aktaş, Aydın, Gök, Yetkin
• Format: Article
• Language: English
• Subjects: 2-iso-propylthiazole; 2-n-butylfuran; 2-n-butylthiophene; Direct arylation; Pd-PEPPSI complexes; X-ray diffraction
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2019.127608

The prestige of the PEPPSI (Pyridine-Enhanced Precatalyst Preparation Stabilization and Initiation) complexes in organometallic chemistry is increasing day by day. Herein, the well-defined seven meta-cyanobenzyl-substituted N-heterocyclic carbene (NHC)–Pd(II)-pyridine (Pd-PEPPSI) complexes were synthesized using palladium acetate, which unlike general procedure is a more economical method than palladium chloride. The new Pd-PEPPSI complexes were obtained from the reaction of the cyanobenzyl substituted NHC precursors and palladium acetate in pyridine. The new complexes have been fully characterized by 1H NMR, 13C NMR, FTIR spectroscopy and elemental analysis techniques. Also, the X-ray diffraction method was used to determine the single-crystal structure of a complex. The Pd-PEPPSI complexes have been examined as catalysts in the direct arylation reactions of 2-n-butylfuran and 2-n-butylthiophene with aryl bromide. All complexes have demonstrated excellent activity in these reactions. The Molecular and crystal structure of one of the cyanobenzyl substituted Pd-PEPPSI complexes was determined by the single-crystal X-ray diffraction method. X-ray diffraction studies show that the molecular structure adopts a slightly distorted square-planar geometry with the palladium (II) center. •The meta-cyanobenzyl-substituted Pd-PEPPSI complexes have been prepared from the NHC precursors and aryl halides.•The Pd-PEPPSI complexes have been characterized by using spectroscopy and elemental analysis techniques.•The Pd-PEPPSI complex 1f was determined by the single-crystal X-ray diffraction method.•The Pd-PEPPSI complexes have been examined as catalysts in the direct arylation reactions.