Details

Autor(en) / Beteiligte

• Vignesh, Arumugam
• Shalini, Chinnuswamy
• Dharmaraj, Nallasamy
• Kaminsky, Werner
• Karvembu, Ramasamy

Titel

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

Ist Teil von

• European journal of inorganic chemistry, 2019-09, Vol.2019 (34), p.3869-3882

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Wiley-Blackwell subscription journals

Beschreibungen/Notizen

• 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. Reaction of aroylhydrazone ligands with [PdCl2(PPh3)2] afforded four new complexes of stoichiometric variation. The influence of the peripheral substituents of aroylhydrazone on the coordination diversity was investigated. The catalytic potential of these complexes was tested towards the Suzuki coupling of sterically challenged arylboronic acids with (hetero)aryl halides.