172878-95-4Relevant articles and documents
Design, synthesis and properties of orthopalladated complexes: Proheterogeneous catalyst
Das, Uttam,Pattanayak, Poulami,Patra, Debprasad,Brand?o, Paula,Felix, Vitor,Chattopadhyay, Surajit
, p. 165 - 171 (2016)
The reaction of multidentate ligand, 3-((E)-(2-((E)-4-aryldiazenyl)phenylimino)methyl)benzene-1,2-diol, H2L (H2L1, 1a; H2L2, 1b and H2L3, 1c) and (E)-2-((2-(aryldiazenyl)phenylamino)methyl)phenol, HA (HA1, 3a; HA2, 3b and HA3, 3c) [where H represents the dissociable protons upon complexation, and aryl groups of H2L and HA are phenyl for H2L1 and HA1, p-methylphenyl for H2L2 and HA2, and p-chlorophenyl for H2L3 and HA3], with Na2PdCl4 separately afforded orthometallated complexes [(L)Pd], (2a, 2b and 2c) and [(A)PdCl] (4a, 4b and 4c) respectively. In the case of [(L)Pd], the deprotonated L2- ligands bind palladium (II) in a tetradentate (C,N,N,O) fashion whereas in the case of [(A)PdCl], the deprotonated A- ligands bind Pd(II) in tridentate (C,N,N) manner. X-ray structures of [(L1)Pd], (2a) and [(A1)PdCl] (4a) were determined to confirm the molecular structures. Both the complexes 4a and 5a exhibited catalytic activity toward Suzuki and Heck reactions. Conversion of [(A)PdCl] to its oxidized form upon ligand oxidation is reported.
Azo-amide palladium(II) complexes: Synthesis, characterization and application in C–C cross-coupling reactions
Pratihar, Jahar Lal,Mandal, Paritosh,Lin, Chia-Her,Lai,Mal, Dasarath
, p. 224 - 230 (2017/08/08)
The newly designed tridentate ligands bis-2,2′-(N-alkylamino)azobenzene, 1a-1d, have been prepared by the reaction between 2,2′-diaminoazobenzene and alkyl halides in the presence of K2CO3. These ligands were reacted with Na2[PdCl4] in a 1:1 ratio in methanol to give the new Pd(II) complexes 2a–2d. All the compounds were characterized by 1H NMR, IR spectroscopy and elemental analysis. Furthermore, the solid-state structures of the ligand 1a and two complexes (2a and 2c) were determined using single crystal X-ray diffraction analysis. The diffraction analysis revealed that the ligands bind with the Pd(II) ion in a monoanionic tridentate (N,N,N) fashion, offering a distorted square planar geometry where the fourth position is occupied by one chloride ligand. The air/moisture stable complex 2a was employed as an efficient catalyst for the Suzuki and Heck reactions under mild conditions. The catalyst exhibits high catalytic activities for the coupling of several aryl halides with phenyl boronic acid and styrene, providing excellent yields. Further, the catalyst can be easily recovered by simple chromatographic separation and reused up to three times without significant loss of its catalytic activity.
Synthesis of a cyclometalated 1,3,5-triphenylpyrazole palladium dimer and its activity towards cross coupling reactions
Mamidala, Ramesh,Mukundam, Vanga,Dhanunjayarao, Kunchala,Venkatasubbaiah, Krishnan
, p. 5805 - 5809 (2015/03/30)
A phosphine free 1,3,5-triphenylpyrazole acetate-bridged palladacycle was prepared from simple commercially available starting materials. The activity of the palladacycle in the Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions was evaluated. The palladacycle precatalyst shows a wide substrate scope, both in Mizoroki-Heck as well as in Suzuki-Miyaura cross-coupling reactions using low catalyst loadings viz., 0.2 mol% and 0.1 mol% respectively.
