Y.S. Kardasheva

Pd Nanoparticles in Dendrimers Immobilized on Silica–Polyamine Composites as Catalysts for Selective Hydrogenation

New heterogeneous hydrogenation catalysts, based on Pd nanoparticles and polypropyleneimine (PPI) dendrimers of the third generation that have been covalently grafted to a silica surface modified with polyallylamine (PAA) have been synthesized. The final products were characterized by TEM, XPS, and solid-state NMR spectroscopy. The synthesized materials are effective catalysts for selective hydrogenation of dienes to monoenes and phenyl acetylene to styrene at very high substrate/Pd ratios with turnover rates higher than related Pd nanoparticle catalysts. The synthesized catalysts can be reused without any loss of activity in the case of styrene and isoprene.

Hydroprocessing of Aromatics Using Sulfide Catalysts Supported on Ordered Mesoporous Phenol–Formaldehyde Polymers

Ni–W sulfide catalysts for the hydroprocessing of aromatic hydrocarbons were synthesized by the in situ decomposition of tetrabutylammonium nickel thiotungstate complex supported on ordered mesoporous phenol–formaldehyde polymer. Catalysts obtained with and without additional sulfidation with dimethyl disulfide were characterized by X-ray photoelectron spectroscopy and transmission electron microscopy. The catalytic activity has been studied using naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, and anthracene as examples. It is shown that the system used in this study proved to be active in hydrogenation and hydrocracking of polyaromatic hydrocarbons.

Surface active macromolecular and supramolecular complexes: design and catalysis

A number of macromolecular and supramolecular catalysts which combine the functions of transition metal complex, phase transfer agent with molecular recognition ability has been designed. The complexes of rhodium, palladium, iron and copper showed the remarkable activity in hydroformylation, Wacker-type oxidation of various olefins, oxidation of alkanes and hydroxylation of aromatics.

Hydroformylation in petroleum chemistry and organic synthesis: Implementation of the process and solving the problem of recycling homogeneous catalysts (Review)

Methods for isolating and recycling homogeneous hydroformylation catalysts used in the industry and promising research works on the development of novel ligands and selection of solvent systems are surveyed. The role of membrane nanofiltration as one of the possible means of separating a homogeneous catalyst from the reaction mixture is specified.

Methylformate as replacement of syngas in one-pot catalytic synthesis of amines from olefins

A new general approach for the one-pot hydroaminomethylation of olefins using methylformate as formylating agent instead of synthesis gas (syngas) has been proposed. Herein we report that a Ru–Rh catalytic system demonstrates high activity in a tandem conversion of a series of n-alkenes into amines using methylformate with yields 58–92% (6 h). The selectivity for the normal amine reached 96% with catalysis by the Ru carbonyl complex Ru3(CO)12, with an overall yield of 55% with respect to amine in this instance. The addition of the Rh complex to Ru catalytic system, sharply increased the hydroaminomethylation rate of both the terminal and internal alkenes and increased the yield of amines to 82–93% (6–12 h).

Synthesis of cyclic acetals by hydroformylation of oct-1-ene in the presence of polyols

Rhodium-catalyzed hydroformylation of oct-1-ene in acid medium in the presence of polyols gives acetals of the initially formed aldehydes. The use of water-soluble trisodium salt of tris(sulfonatophenyl)phosphine as a ligand favors easy separation of the reaction products and enables repeated use of the catalytic system. A minor additive (2 wt.%) of the obtained acetal mixture improves the lubricating properties of diesel fuel by 30% and markedly reduces gum formation during combustion.

Synthesis of polyfunctional phosphorus-containing calixarenes in cycloaddition reactions of azides to alkynes

Mono- and dibromo derivatives of calix[4]arene were used for the first time in phosphorylation, alkylation, and azide-alkyne cycloaddition sequence in order to synthesize polyfunctional macrocycles containing phosphine oxide groups at the upper rim and 1,4-disubstituted triazole rings at the lower rim. The effect of reaction conditions onto the selectivity of the lower-rim alkylation of phosphoruscontaining calixarenes and the ratio of spatial isomers in the exaustively alkylated products was studied. The reduction of phosphine oxide groups and modification of functional groups in the triazole rings were used for the synthesis of bulky hydrophilic phosphinecontaining ligands. The catalytic activity of in situ obtained rhodium complexes of phosphine-containing calixarenes was preliminarily studied by 1-octene hydroformylation in ethanol.