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Catalytic activity of nickel(II), copper(II) and oxovanadium(II)‐dihydroindolone complexes towards homogeneous oxidation reactions
Author(s) -
Adam Mohamed Shaker S.
Publication year - 2018
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.4234
Subject(s) - chemistry , catalysis , aqueous solution , inorganic chemistry , acetonitrile , copper , homogeneous catalysis , metal ions in aqueous solution , nickel , catalytic oxidation , nuclear chemistry , metal , medicinal chemistry , organic chemistry
Three novel paramagnetic metal complexes (MH 2 ID) of Ni 2+ , Cu 2+ and VO 2+ ions with 3‐hydroxy‐3,3’‐biindoline‐2,2’‐dione (dihydroindolone, H 4 ID) were synthesized and characterized by different spectroscopic methods. The ligand (H 4 ID) was synthesized via homocoupling reaction of isatin in presence of phenylalanine in methanol. Complexation of low valent Ni 2+ , Cu 2+ ions and high valent VO 2+ ions with H 4 ID carried out in 1: 2 molar ratios. A comparison in the catalytic potential of paramagnetic complexes of low and high valent metal ion was explored in the oxidation processes of cis ‐cyclooctene, benzyl alcohol and thiophene by an aqueous H 2 O 2 , as a green terminal oxidant, in the presence and absence of acetonitrile, as an organic solvent, at 85 °C. NiH 2 ID, CuH 2 ID and VOH 2 ID show good catalytic activity, i.e. good chemo‐ and regioselectivity. VOH 2 ID has the highest catalytic potential compared to both Ni 2+ ‐ and Cu 2+ ‐species in the same homogenous aerobic atmosphere. Catalytic oxidation of other alkenes and alcohols was also studied using NiH 2 ID, CuH 2 ID or VOH 2 ID as a pre‐catalyst by an aqueous H 2 O 2 . A mechanistic pathway for those oxidation processes was proposed.