Novel 2-hydroxyethyl substituted N-coordinate-Pd(II)(NHC) and bis(NHC)Pd(II) complexes: Synthesis, characterization and the catalytic activity in the direct arylation reaction

Abstract

The direct arylation reaction has attracted attention in recent years especially because of its environment-friendly properties. In this study, we researched the synthesis of 2-hydroxyethyl substituted bis(NHC)Pd(II) complexes and also the synthesis of N-coordinate-Pd(II)(NHC) complexes containing Nbound benzimidazolium from palladium acetate ([Pd(CH 3 COO) 2 ]) with 1,3-disubstituted benzimidazolium halides in DMSO. All the complexes have been characterized by using 1 H NMR, 13 C NMR, FTIR spectroscopy and elemental analysis techniques. The molecular and crystal structure of one of the complexes is confirmed by using single-crystal X-ray diffraction. These complexes have been examined as the catalyst in the direct arylation reaction with 2-n-butylfuran and 2-n-butylthiophene and have demonstrated excellent activity in this reaction.

A Novel Ag-N-Heterocyclic Carbene Complex Bearing the Hydroxyethyl Ligand: Synthesis, Characterization, Crystal and Spectral Structures and Bioactivity Properties

“…The band at 1288 cm −1 corresponds to the primary alcohol (hydroxyethyl group) O-H in-plane bending vibration. The symmetrical for Ccarbene-N stretching frequency in the benzimidazole group observed intense at 1397 cm −1 [48,49]. According to the literature, Ag-C stress vibrations are expected in the frequency region of 400-155 cm −1 [50].…”

Direct Arylation in the Presence of Palladium Pincer Complexes

“…Therefore, the palladium-catalyzed direct arylation of chloroarenes is usually carried out in the presence of the above trialkyl- and biphenylphosphanes or N -heterocyclic carbenes (NHC) as ligands. Jeffery’s ligand-free conditions have also been successfully used in this field [ 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ]. Catalyst loading generally ranges from 1 to 20 mol%.…”