Marek Gliński

Ketones from monocarboxylic acids: Catalytic ketonization over oxide systems

The ketonization of acetic acid was studied in the presence of a series of 20 oxide catalysts supported on SiO2, TiO2 and Al2O3. The reactions were performed in the continuous flow reactor. Ceria-and mangania-containing catalysts exhibited the highest activity. The influence of the oxide phase concentration, liquid hourly space velocity and of the type of the catalyst carrier on the acetone yield was determined. Alumina support showed the most pronounced effect on the activity of deposited oxides. High yields of 3-pentanone, 6-undecanone, and 7-tridecanone were achieved in the ketonization of appropriate acids in the presence of mangania and ceria catalysts in large-scale laboratory experiments.

Catalytic ketonisation over oxide catalysts

Activity of pure Al2O3 has been studied in cycloketonisation of various dialkyl alkanodiates of general formula (CH2)n(COOR)2, where n = 4, 5, 6, 7, 8 and 10 and R = Et, s-Bu and t-Bu at the temperature range 598-723 K in a flow system. The yields of cycloalkanones strongly depend on the size of the ring formed, the structure of alkyl group in ester molecule and on the reaction temperature. Cyclopentanone, cyclohexanone and cycloheptanone were obtained with yields 50-60% from the appropriate diethyl esters. The only low yields (<8%) of cyclooctanone, cyclononane and cycloundecanone were achieved. An increase in the order of the ester alkyl group leads in some cases to higher yields of ketones - di t-butyl hexanodiate yielded 88% of cyclopentanone.

Reduction of alkyl alkyl, aryl alkyl and cyclic ketones by catalytic hydrogen transfer over magnesium oxide

The reduction of a series of alkyl alkyl, aryl alkyl and cyclic ketones by catalytic hydrogen transfer (CTR) from isopropyl alcohol over magnesium oxide has been investigated. CTR over MgO was found to be an effective and selective route to the corresponding methanols. At temperatures above 523 K para-substituted phenylmethanols underwent consecutive dehydration leading to the formation of the corresponding styrene derivatives with satisfying yields. These processes were studied in a flow system working continuously. A long-time stability of the catalyst activity has been demonstrated.

Catalytic Ketonization over Oxide Catalysts, Part IV. Cycloketonization of Diethyl Hexanodiate

Activity of 20 wt.% MO2/S catalysts, where M = Mn, Ce and Th, and S = Al2O3 or SiO2, has been studied in cycloketonization of diethyl hexanodiate at the temperature range 573-698 K in a flow system. Only moderate yields of cyclopentanone (<35%) were achieved. The highest yields of ketone were obtained over MnO2/Al2O3 and MnO2/SiO2 catalysts - 33 and 27%, respectively. ThO2 containing catalysts were the most active, whereby ester transformations were detected below 573 K. In the presence of all catalysts the formation of the main product was accompanied by various amounts of 2-ethylcyclopentanone, cyclopent-2-en-1-one, cyclopentene, 2-cyclopentylidenecyclopentanone and numerous unidentified by-products.

Catalytic hydrogen transfer over magnesia, IXa. reduction of long chain aliphatic ketones by 2-propanol

A series of symmetrical long chain aliphatic ketones of general formula CH3−(CH2)n-CO-(CH2)2−CH3, where n=4,5,6,7 and 8, has been used as hydrogen acceptors from 2-propanol at 573–723 K in the presence of MgO catalyst under flow conditions. The yeilds of the appropriate alcohols exceeded 50%. Above 623 K the consecutive dehydration of the alcohols formed took place with moderate yields leading to internal alkenes. The direct one-step synthesis of C13 alkene from 7-tridecanone has been realized under catalytic transfer reduction (CTR) conditions with high yield (>90%) over a MgO catalyst of enhanced acidity.

Monolayer vanadia on titania systems from alkoxide precursors. Part I. Physicochemical properties

The physicochemical properties of V5+ ion monolayers supported on anatase, rutile, and anatase-rutile mixed carrier, using vanadyl triisobutoxide as the precursor have been investigated. The coordination and reducibility of surface vanadyl species were found to depend strongly on carrier material and its calcination temperature. The supported monolayers exhibited completely different reduction behavior than bulk V2O5. The rutile supported catalyst was the most resistant for reduction.AbstractИсследовали физико-химические свойства монослоев ионов V5+, нанесенных на анатазу, рутил и смешанных анатазу-рутил, используя ванадил-триизобутоксид в качестве прекурсора. Координация и восстанавливаемость поверхностных ванадильных частиц сильно зависят от материала носителя и температуры кальцинирования. Нанесенные монослои восстанавливаются совсем иначе, чем блочные V2O5. Наиболее устойчивым к восстановлению оказался катализатор, нанесенный на рутил.

Catalytic ketonization over oxide catalysts, Part VI.a Cross-ketonization of aliphatic and aromatic esters

Activity of 20 wt.% MO2/Al2O3 catalysts, where M = Mn, Ce and Zr has been studied in cross-ketonization of ethyl esters of aliphatic and aromatic acids in a flow system. Pentan-3-one and tridecan-7-one were formed in ketonization of pure aliphatic esters, ethyl propanoate and ethyl heptanoate. Benzene was obtained instead of diphenylmethanone as the product of ethyl benzoate transformations. Only two ketones, dialkyl and aralkyl, were obtained from the cross-ketonization of a mixture of aliphatic and aromatic esters. The highest yield of 1-phenyl-1-heptanone (70%) from ethyl heptanoate and ethyl benzoate was reached at 698 K in the presence of MnO2/Al2O3 catalyst. Under similar conditions cross-ketonization of a mixture of ethyl propanoate and ethyl benzoate led to 1-phenyl-1-propanone (60% at 673 K).

The factors controlling the reaction of (2,4,6-triisopropylphenyl) methyl ketone with Ph3Al and structure of [Ph2AlO(2,4,6-tri-iPr-C6H2)CCH2]2

Abstract The reaction of (2,4,6)-tri-isopropylphenyl methyl ketone with tri-phenylaluminium was investigated. [Ph 2 AlO(2,4,6-tri- i Pr-C 6 H 2 )CCH 2 ] 2 was found to be formed exclusively. The title compound has been characterised by NMR and its crystal structure determined by X-ray diffraction study.

The direct synthesis of alkenylaromatics during catalytic transfer reduction (CTR) of aralkyl ketones with isopropyl alcohol over MgO of enhanced acidity

Abstract The direct synthesis of alkenylaromatics during catalytic transfer reduction (CTR) of aralkyl ketones with isopropyl alcohol over MgO of enhanced acidity has been investigated. Magnesia was successfully modified with H 2 SO 4 and H 3 PO 4 . The studied ketones, acetophenone, 4-isopropylacetophenone, propiophenone, and 5-nonanone, were quantitatively transformed to alkenes under the adopted conditions. A long-time stability of the catalysts activity and reaction selectivity has been demonstrated.

Antimicrobial activity of undecan-2-one, undecan-2-ol and their derivatives.

Abstract The antimicrobial activity of Undecan-2-one, its ethylene acetal, racemic mixture and enantiomers of Undecan-2-ol, and undec-2-yl acetate, towards bacteria Escherichia coli, Bacillus subtilis, yeast Candida mycoderma and mould Aspergillus niger was investigated. These components are abundantly present in essential oils obtained from various rue species. The essential oil from Ruta chalepensis L. growing in Turkey contains 66.5 %Undecan-2-one, and that from Ruta Montana L. even 84.2 %. Chinese Ruta graveolens L. contains 67.0 % of this ketone. Dextrorotatory S-( + )-undecan-2-ol is a component of cocoa butter, and its R-( − )- enantiomer occurs in the essential oil from leaves of Litsea odorifera. The population viability of tested microbial strains in the presence of the investigated compounds was determined by the impedimetric method. Undecan-2-one showed low activity towards bacteria but it was more efficient in the case of yeasts and moulds. Other tested compounds exhibited different bacteriostatic activity towards B. subtilis and they had no effect on bacteria E. coli and yeast C. mycoderma. The antimicrobial activity of enantiomers was diverse and wasn’t always the same as that determined for racemic mixture of the compound. The S( + ) enantiomer of Undecan-2-ol showed a similar activity to that of the racemic mixture, however both enantiomers of undec-2-yl acetate exhibited higher activity towards bacteria B. subtilis than the racemic mixture. The tested compounds can be used as growth inhibitors of Gram-positive bacteria B. subtilis and mould A. niger in food and cosmetic products.