666726-60-9Relevant academic research and scientific papers
Delineating the Role of Substituents on the Coordination Behavior of Aroylhydrazone Ligands in PdII Complexes and their Influence on Suzuki–Miyaura Coupling in Aqueous Media
Vignesh, Arumugam,Shalini, Chinnuswamy,Dharmaraj, Nallasamy,Kaminsky, Werner,Karvembu, Ramasamy
, p. 3869 - 3882 (2019)
Reactions of piperonal aroylhydrazone ligands (HL1–HL4) with [PdCl2(PPh3)2] in CH3OH and CHCl3 afforded four new Pd(II) complexes (1–4) featuring diverse coordination behaviors. These complexes 1–4 were fully characterized by elemental analyses, UV/Visible, FT-IR and 1H/13C NMR spectra. The variant coordination modes of piperonal aroylhydrazone ligands with Pd(II) ion in these complexes were unambiguously confirmed by single-crystal XRD study. Though the ligands HL1–HL4 are of similar nature, one of them (HL4) possessing an electron withdrawing nitro group as substitution in the peripheral part of the hydrazone displayed an uncommon ligation towards the palladium ion. An experimentally observed molecular architects were in turn rationalized by density functional theory (DFT) calculations as well as natural bonding analysis (NBO). All these Pd(II) complexes were evaluated for their catalytic potential towards Suzuki–Miyaura cross-coupling reaction of sterically congested arylboronic acids with (hetero)arylhalides under an open-flask conditions in aqueous media with low catalyst loading. Advantageously, the selected catalyst was active up to five cycles without significant loss in activity.
Palladium catalyzed Suzuki-Miyaura coupling with aryl chlorides using a bulky phenanthryl N-heterocyclic carbene ligand
Song, Chun,Ma, Yudao,Chai, Qiang,Ma, Chanqin,Jiang, Wei,Andrus, Merritt B.
, p. 7438 - 7446 (2007/10/03)
A novel bis-phenanthryl N-heterocyclic carbene (NHC) based palladium acetate catalyst was effective for the coupling of various aryl and vinyl chlorides with organoboron compounds. N,N-Bis-(2,9-dicyclohexyl-10-phenanthryl)- 4,5-dihydroimidazolium chloride 8 (H2ICP·HCl) with Pd(OAc)2 and KF·18-c-6 in THF at room temperature gave Suzuki-Miyaura coupling of aryl and vinyl chorides, including unactivated and di-ortho substituted substrates in high yields. Hindered tri- and tetra-ortho substituted products were also efficiently produced. Benzyl chloride was also found to be a useful coupling partner and trimethylboroxine was used to give methylated products. The effect of ligand, base, temperature, solvent, and reaction time are reported along with various substrates including halides and triflates.
