Nanostructured regular materials based on dendrimers bound by covalent or coordination bonds between surface functional groups were synthesized. Bimetallic Cu(II) and Pd(II) metal complexes with nitrile-based dendrimers demonstrated high activity in Wacker oxidation of terminal alkenes along with good selectivity for methylketone formation. New heterogeneous catalysts based on Pd nanoparticles and cross-linked polypropylene imine (PPI) and polyamidoamine (PAMAM) dendrimers were prepared and examined for selective hydrogenation of unsaturated compounds.
A number of complexes of copper(II) and iron(III) with different N,N and N,O ligands were tested as catalysts for the hydroxylation of phenol to dihydroxybenzene by hydrogen peroxide for the purpose of achieving a high catechol selectivity. Cu(II) complexes were demonstrated to give a high selectivity on catechol. The best selectivity was found for Cu(II) complex with 2,6-dihydroxypiridine. The best conditions for the selective formation of catechol were the reaction time of 15 min and a ratio of 2,6-dihydroxypiridine to copper greater than 3 (65 °C). The concentration of phenol and the reaction time had a dramatic influence on the catechol yield and selectivity for most selective catalysts. At high concentrations and reaction times, both the catechol yield and selectivity decreased, with tars being formed.
The results of studying a number of reactions catalyzed by several types of soluble macromolecular catalytic systems capable of selectively binding organic substrates, namely, modified cyclodextrins, calixarenes and dendrimers are presented. The use of modified cyclodextrins as components of a catalytic system in the phenol and benzene hydroxylation by hydrogen peroxide allows one both to increase the catalytic activity and to change significantly the chemical selectivity. Phosphorilated calixarene -Rh catalytic systems was found to be catalytically active in hydroformylation of linear alkenes C 7 -C 12 . The results of experiments on the oxidation of C 7 -C 16 alkenes show that, when the ligand is the dendrimer molecule, the fraction of forming methyl ketones substantially increases for the substrates C 7 -C 9 . For the higher alkenes, this effect is not observed.
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