Electrochemical investigation of complexation of polymer ligands containing 2,2′-biquinolyl fragments with NiII ions in solution

Polymer biquinolyl-containing complexes of Pd(ii) as efficient catalysts for cyanation of aryl and vinyl halides with K4Fe(CN)6

“…The reaction mixtures obtained after the cyanation reactions were analyzed using a ''Pegasus 4D'' (LECO) GC/MS spectrometer (ionization energy 70 eV, a DB-5MS quartz capillary column (30 m), temperature mode: 50 1C (2 min)-280 1C (15 min), heating rate 20 deg min À1 ). 1 H and 13 C NMR spectra were recorded using a Varian VXR 400 in CDCl 3 . Chemical shifts were measured relative to TMS.…”

“…After the standard workup procedure, the products were analyzed using GC-MS (with the internal standard). Z-E configurations of the starting bromides and the corresponding nitriles were determined using 1 H and 13 C NMR. The chemical shifts of the signals of aand b-protons in the bromides and nitriles with Z-and E-configurations differ significantly.…”

“…This allows reliable control on the stereoselectivity of the process as well as the estimation of the conversion degree. Additional information can be obtained from the 13 C NMR signals of the nitrile carbon which are different for Z-and E-nitriles.…”

“…Thus, E-and Z-cinnamonitriles can be distinguished due to the difference in the chemical shifts of the doublet signals corresponding to the a-protons (at 5.89 and 5.45 ppm, respectively 69 ). In the case of 2-phenylcinnamonitrile, the signals of the E-and Zisomers in 1 H NMR spectra are overlapped and the determination of the configuration of the product was based on 13 C NMR data, on the signals corresponding to the nitrile carbon atom which are well distinguished (chemical shifts are 120 ppm for the E-isomer and 118 ppm for the Z-isomer 70 ). Differentiation between E-and Z-nitriles of 2-carbomethoxy cinnamon acid and determination of their relative amounts are more convenient to perform considering the singlets corresponding to the protons of the methyl group (chemical shifts are 3.76 ppm and 3.91 ppm for the E-and Z-isomer 71 ).…”

“…The presence of the CH 2 -group between two aromatic rings ensures plasticity, and imide fragments in the copolymer are responsible for the tensile strength of the polymer. The biquinolyl (biQ) fragments in the main chain of the polymer backbone provide an opportunity for coordination to transition metal ions, e.g., Ni(II), 13,14 Cu(I), [15][16][17][18] Pd(II), 17,19 yielding polymer complexes which show excellent efficiency in electrocatalytic aerobic oxidation of aliphatic alcohols 15 and amines 16 to corresponding carbonyl compounds as well as in catalysis for C-C bond formation (Suzuki-Miyaura 19 and Sonogashira 17,18 couplings).…”