1000396-27-9Relevant academic research and scientific papers
Mechanistic Insights into Pincer-Ligated Palladium-Catalyzed Arylation of Azoles with Aryl Iodides: Evidence of a PdII-PdIV-PdII Pathway
Khake, Shrikant M.,Jagtap, Rahul A.,Dangat, Yuvraj B.,Gonnade, Rajesh G.,Vanka, Kumar,Punji, Benudhar
supporting information, p. 875 - 886 (2016/04/19)
Pincer-based (R2POCNR′2)PdCl complexes along with CuI cocatalyst catalyze the arylation of azoles with aryl iodides to give the 2-arylated azole products. Herein, we report an extensive mechanistic investigation for the direct arylation of azoles involving a well-defined and highly efficient (iPr2POCNEt2)PdCl (2a) catalyst, which emphasizes a rare PdII-PdIV-PdII redox catalytic pathway. Kinetic studies and deuterium labeling experiments indicate that the C-H bond cleavage on azoles occurs via two distinct routes in a reversible manner. Controlled reactivity of the catalyst 2a underlines the iodo derivative (iPr2POCNEt2)PdI (3a) to be the resting state of the catalyst. The intermediate species (iPr2POCNEt2)Pd-benzothiazolyl (4a) has been isolated and structurally characterized. A determination of reaction rates of compound 4a with electronically different aryl iodides has revealed the kinetic significance of the oxidative addition of the C(sp2)-X electrophile, aryl iodide, to complex 4a. Furthermore, the reactivity behavior of 4a suggests that the arylation of benzothiazole proceeds via an oxidative addition/reductive elimination pathway involving a (iPr2POCNEt2)PdIV(benzothiazolyl)(Ar)I species, which is strongly supported by DFT calculations.
New PCN and PCP pincer palladium(II) complexes: convenient synthesis via facile one-pot phosphorylation/palladation reaction and structural characterization
Gong, Jun-Fang,Zhang, Yan-Hui,Song, Mao-Ping,Xu, Chen
, p. 6487 - 6492 (2008/10/09)
A series of new PCN pincer palladium(II) complexes with phosphinito group 2a - d and 3 were conveniently prepared via facile one-pot phosphorylation/ palladation reaction of pyrazolyl or aminocontaining m-phenol derivatives with chlorophosphines and PdCl2. Two PCP pincer complexes 4a,b were also readily obtained from resorcinol in an analogous yet simplified manner. AU of the new complexes have been fully characterized by 1H NMR, 13C{1H} NMR, 31P{1H} NMR, IR, ESI-MS, and elemental analysis. Additionally, the molecular structures of 2a - d have been determined by X-ray single-crystal diffraction.
