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1
Content available remote Synthesis of the cross-linked humic acid supporting palladium catalyst and its catalytic properties for Heck reaction
100%
Xu Q. , Shi W. , Cui Y.
Polish Journal of Chemical Technology
|
2012
|
tom 14
|
nr 2
75-79
EN
Cross-linked humic acid supporting palladium (CL-HA-Pd) catalyst was prepared readily and characterized by infrared analysis (IR) and thermogravimetric analysis (TG). The catalyst could catalyze the Heck reaction of aryl halide or substituted aryl halide with vinyl compounds in N2 atmosphere; the yields were above 95%. The catalyst could be recovered and reused 7 times with the Heck reaction of iodobenzene with acrylic acid, and the yield was above 75.6%. The results showed that the catalyst had high catalytic activity even at low temperature of 62°C or with a small amount of the catalyst.
2
Content available remote Platinum complex catalysts immobilized on epoxy resins cured with polythiourethane hardeners
88%
Strzelec K. , Bączek N.
Open Chemistry
|
2015
|
tom 13
|
nr 1
EN
Some efficient polymer-supported platinum catalysts have been synthesized through the novel application of epoxy resin D.E.R.TM332 cured with polythiourethanes. Epoxide supports were obtained as a result of the use of polythiourethane hardeners. The activity, stability and selectivity during long-term use of the investigated catalytic systems were tested in a hydrogenation reaction of cinnamaldehyde. The results of this study indicate that polythiourethanes used to cure epoxy resin can also greatly affect the catalytic properties of the epoxide-supported platinum catalysts. To fully characterize both polymeric supports and heterogenized catalysts numerous research methods like time-of-flight secondary ion mass spectrometry (ToF-SIMS), infrared spectroscopy (IR), X-Ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM-EDX) and nitrogen BET surface area measurements were used.
3
Content available remote Catalytic performances of cross-linking humic acids supported Pd/Ni bimetallic catalyst for heck reaction
88%
Xu Q. , Zhang L. , Shi W. , Cui Y.
Polish Journal of Chemical Technology
|
2009
|
tom 11
|
nr 3
22-26
EN
The cross-linking humic acids (CL-HAs), epichlorohydrin as the cross-linking reagent and the supported Pd/Ni bimetallic catalysts (CL-HAs-Pd/Ni) were prepared and characterized by IR, AAS, XPS, TEM. The effects of reaction time, temperature, base, solvent and the amount of catalyst on the properties of the catalyst were studied. These catalysts could catalyze the Heck reaction of aryl halides and substituted aryl halides with acrylic acids or styrene successfully; the yields were all above 95%.
4
Content available remote Magnetic recykling of complex catalysts immobilized on thiol-functionalized polymer supports
75%
Bączek N. , Strzelec K. , Wąsikowska K.
Polish Journal of Chemical Technology
|
2013
|
tom 15
|
nr 3
65-68
EN
In this work, the application of the thiol-functionalized epoxy resin encapsulated on magnetic core as supports for palladium catalysts is reported. The study focuses on obtaining of heterogeneous catalysts which can be separated by magnetic field. Palladium complex catalyst [PdCl2(PhCN)2] has been heterogenized by anchoring to these supports via ligand exchange reaction. The characterization of polymeric supports and heterogenized palladium catalysts has involved research methods like time-of-flight secondary ion mass spectrometry (TOF-SIMS), scanning electron microscopy (SEM) and nitrogen BET surface area measurements. The activity and stability during long-term use of the investigated catalytic systems were tested in a Heck and hydrogenation reaction. The influence of the type of thiols used as epoxy hardeners and the morphology of the supports on the catalytic properties of epoxy-supported palladium catalysts was discussed.
5
Palladium Complexes in Carbohydrate Synthesis
75%
Zamojski A.
Polish Journal of Chemistry
|
2002
|
tom Vol. 76 / nr 8
1053-1084
EN
The survey reports the results achieved in carbohydrate synthesis by application of organopalladium complexes. Most remarkable results have been noted in C-glycoside synthesis and in the chemistry of unsaturated sugars. In the majority of cases high regio- and stereoselectivity of transformations is observed. Many palladium catalysts with different organic ligands have been employed. The literature up to the end of 2001 is reviewed.
6
Content available remote Recykling metalokompleksowych katalizatorów immobilizowanych na nośnikach polimerowych
75%
Bączek N. , Strzelec K. , Wąsikowska K.
Przemysł Chemiczny
|
2013
|
tom T. 92, nr 11
1969-1971
PL
Przedstawiono możliwość wykorzystania procesu enkapsulacji makrocząstek ferromagnetyka do otrzymywania efektywnych heterogenizowanych katalizatorów metalokompleksowych. W tym celu opiłki żelaza o średniej wielkości ziarna ok. 2 mm pokryto warstwą żywicy epoksydowej funkcjonalizowanej grupami tiolowymi. Pokazano możliwość wykorzystania tego typu nośników w procesie immobilizacji kompleksu palladu. Przygotowane ferromagenetyczne katalizatory wykazały dużą aktywność oraz stabilność w reakcji Hecka oraz w reakcji uwodornienia. Omówiono czynniki wpływające na właściwości katalityczne otrzymanych katalizatorów.
EN
Fe filings were encapsulated in a thiol groups-contg. epoxy resin, used as supports for immobilization of the PdCl2(PhCN)2 catalyst, and then for studying Heck reaction of PhI with CH2=CHCOOMe to trans-PhCH=CHCOOMe and hydrogenation reaction of PhCH=CHCHO to Ph(CH2)3OH. A high conversion of raw materials (71–98%) was achieved in both cases. The catalyst showed high activity and stability in the studied reactions and only small losses of Pd mass were obsd. after multiple use of the catalysts.
7
Content available SCREENING OF THE CATALYTIC ACTIVITY OF Pd0 AND Pd2+- SUPPORTED ON CHITOSAN BEADS AND CRYOGELS
75%
Pestov A. , Mekhaev A. , Privar Y. , Prokuda N. , Modin E. , Bratskaya S.
Progress on Chemistry and Application of Chitin and its Derivatives
|
2018
|
tom 23
149 - 158
EN
Here, we report the results of screening of the catalytic activity of Pd-containing chitosan beads and cryogels in the cross-coupling reaction, hydrogenation of alkenes, nitro-, and carbonyl compounds and the hydrodechlorination of chlorophenols. Pd0-containing chitosan beads and cryogels show moderate catalytic activity in the reduction of alkenes and nitroaromatics. The conversion of nitroaromatics decreases for substrates with electron-withdrawing substituents, while the conversion of alkenes increases with the activation of carbon-carbon double bonds. For several substrates, a significant difference in kinetics and conversion degrees was observed for Pd nanoparticles supported on chitosan beads and cryogels. It was found that conversion in the hydrodechlorination reaction depends on substrate structure, being higher for substrates containing substituents with a positive mesomeric effect. Pd2+-chitosan catalysts showed high catalytic activity in cross-coupling (Heck reaction) offering the following advantages over known catalytic systems: lower reaction temperature, the selective functionalisation of C-I bonds, and the possibility to perform reactions with iodobenzene without base addition.
8
Content available Synthesis of the cross-linked humic acid supporting palladium catalyst and its catalytic properties for Heck reaction
75%
Xu Q. , Shi W. , Cui Y.
Polish Journal of Chemical Technology
|
2012
|
tom Vol. 14, nr 2
75-79
EN
Cross-linked humic acid supporting palladium (CL-HA-Pd) catalyst was prepared readily and characterized by infrared analysis (IR) and thermogravimetric analysis (TG). The catalyst could catalyze the Heck reaction of aryl halide or substituted aryl halide with vinyl compounds in N2 atmosphere; the yields were above 95%. The catalyst could be recovered and reused 7 times with the Heck reaction of iodobenzene with acrylic acid, and the yield was above 75.6%. The results showed that the catalyst had high catalytic activity even at low temperature of 62°C or with a small amount of the catalyst.
9
Content available Magnetic recykling of complex catalysts immobilized on thiol-functionalized polymer supports
75%
Bączek N. , Strzelec K. , Wąsikowska K.
Polish Journal of Chemical Technology
|
2013
|
tom Vol. 15, nr 3
65-68
EN
In this work, the application of the thiol-functionalized epoxy resin encapsulated on magnetic core as supports for palladium catalysts is reported. The study focuses on obtaining of heterogeneous catalysts which can be separated by magnetic field. Palladium complex catalyst [PdCl2(PhCN)2] has been heterogenized by anchoring to these supports via ligand exchange reaction. The characterization of polymeric supports and heterogenized palladium catalysts has involved research methods like time-of-flight secondary ion mass spectrometry (TOF-SIMS), scanning electron microscopy (SEM) and nitrogen BET surface area measurements. The activity and stability during long-term use of the investigated catalytic systems were tested in a Heck and hydrogenation reaction. The influence of the type of thiols used as epoxy hardeners and the morphology of the supports on the catalytic properties of epoxy-supported palladium catalysts was discussed.
10
Content available Catalytic performances of cross-linking humic acids supported Pd/Ni bimetallic catalyst for heck reaction
63%
Xu Q. , Zhang L. , Shi W. , Cui Y.
Polish Journal of Chemical Technology
|
2009
|
tom Vol. 11, nr 3
22-26
EN
The cross-linking humic acids (CL-HAs), epichlorohydrin as the cross-linking reagent and the supported Pd/Ni bimetallic catalysts (CL-HAs-Pd/Ni) were prepared and characterized by IR, AAS, XPS, TEM. The effects of reaction time, temperature, base, solvent and the amount of catalyst on the properties of the catalyst were studied. These catalysts could catalyze the Heck reaction of aryl halides and substituted aryl halides with acrylic acids or styrene successfully; the yields were all above 95%.
11
Content available Wpływ środowiska zasadowego na wydajność reakcji Hecka stosowanej do sieciowania kauczuku chloroprenowego
63%
Dziemidkiewicz A. , Maciejewska M.
Elastomery
|
2019
|
tom T. 23, nr 3
163--174
PL
Celem przeprowadzonych badań było określenie wpływu trietanoloaminy (TEOA) na wydajność reakcji Hecka stosowanej do sieciowania kauczuku chloroprenowego (CR). Zaproponowany układ sieciujący jest nowym przykładem zastosowania, doskonale znanej w syntezie organicznej, reakcji Hecka [1]. Reakcja ta jest jedną z głównych metod tworzenia wiązań podwójnych węgiel–węgiel (C=C) w syntezie organicznej. Nie odnotowano jak dotąd żadnego wykorzystania reakcji Hecka w technologii elastomerów. Sporządzono mieszanki kauczukowe zawierające acetyloacetonian żelaza(II) (Fe(acac)2) jako nowy środek sieciujący z różną zawartością TEOA (1–5 cz. mas.). Dodatkowo mieszanki napełniono krzemionką (SiO2) pirogeniczną Aerosil 380 lub sadzą (CB) N550. Uzyskane wyniki wykazały, że zarówno ilość TEOA, jak i rodzaj napełniacza miały istotny wpływ na właściwości otrzymanych elastomerów. W przypadku kompozytów napełnionych CB aktywność Fe(acac)2 w procesie sieciowania wzrastała wraz z ilością TEOA. Potwierdziły to wysokie wartości przyrostu momentu obrotowego i stopnia usieciowania CR oraz krótsze czasy wulkanizacji. W przypadku mieszanek napełnionych SiO2 wpływ ilości TEOA na wydajność procesu sieciowania nie był tak jednoznaczny. Jednak biorąc pod uwagę przyrost momentu obrotowego, stopień usieciowania oraz optymalny czas wulkanizacji można stwierdzić, że użycie 3 cz. mas. TEOA skutkowało największą aktywnością Fe(acac)2.
EN
The aim of the study was to determine the effect of triethanolamine (TEOA) on the efficiency of Heck’s reaction used for the crosslinking of chloroprene rubber (CR). The proposed crosslinking system is a new example of the application of the Heck reaction, well known in organic synthesis [1]. This reaction is one of the main methods of creating carbon‑carbon double bonds (C=C) in organic synthesis. So far, no use of Heck’s reaction in elastomer technology has been reported. Rubber blends containing iron(II) acetylacetonate (Fe(acac)2) as a new crosslinking agent with different TEOA content (1–5 phr) were prepared. Additionally, the blends were filled with pyrogenic silica (SiO2) Aerosil 380 or carbon black (CB) N 550. The obtained results showed that both the amount of TEOA and the type of filler had a significant effect on the properties of the elastomers obtained. In case of composites filled with CB, the activity of Fe(acac)2 in the crosslinking process increased with the amount of TEOA. This was confirmed by high values of torque increment and degree of crosslinking of CR and shorter vulcanization times. In case of rubber compounds filled with SiO2, the effect of TEOA on the efficiency of crosslinking process was not so unambiguous. However, considering the increase in torque, the degree of crosslinking and the optimum vulcanization time, it can be stated that the use of 3 phr. TEOA resulted in the highest Fe(acac)2 activity.
12
Content available remote Wpływ hydroksylowych cieczy jonowych na reakcję Hecka katalizowaną związkami palladu
63%
Tarnowicz S. , Trzeciak A. M. , Nowicki J.
Przemysł Chemiczny
|
2016
|
tom T. 95, nr 4
843--846
PL
Zaprezentowano wyniki użycia cieczy jonowych funkcjonalizowanych grupami hydroksylowymi jako kokatalizatorów w reakcji Hecka katalizowanej związkami palladu. Zbadano ciecze jonowe z anionami hydroksylowymi i dicyjanoimidkowymi. Zaobserwowano pozytywny wpływ obecności cieczy jonowych z tej grupy na wydajność reakcji Hecka. Najlepsze wyniki (54% i 60% cynamonianu butylu) uzyskano w obecności katalizatora [glymim]₂[PdCl₄] z solą [glymim]Cl.
EN
1-(2,3-Dihydroxypropyl)-3-methylimidazolium hydroxide ([glymim]OH),1-hexyl-3-methylimidazolium hydroxide and 1-butyl-1,8-diazabicyclo[5.4.0]undec-7-ene hydroxide ionic liqs. were used as co-catalysts in the Pd-catalyzed Heck reaction of PhBr with CH₂=CHCOOBu. The highest yield of PhCH=CHCOOBu (60%) was obtained for [glymim]₂[PdCl₄] complex at 140°C in Me₂NCHO.
13
Content available remote Nanocząsteczkowe katalizatory palladowe w reakcjach tworzenia wiązań C-C
51%
Trzeciak A. M. , Ziółkowski J. J.
Wiadomości Chemiczne
|
2009
|
tom [Z] 63, 1-2
1-15
EN
The important role of palladium nanoparticles has been recently demonstrated in many catalytic systems designed for C-C bond forming reactions [1-4]. There are examples of catalytic systems described earlier as homogeneous in which Pd(0) nanoparticles were now identified. In the article three different palladium catalytic systems are discussed. In the first one, Pd(0) nanoparticles, obtained by chemical reduction of PdCl2 and stabilized by polyvinylpyrrolidone, were used for Heck coupling in [Bu4N]Br medium. Decrease of nanoparticles size in reaction conditions was explained as a result of dissolution of Pd(0) colloid and simultaneous formation of catalytically active monomolecular anionic palladium complexes [33]. The second example presents application of Pd(II) and Pd(0) supported on alumina-based oxides in Suzuki-Miyaura reaction [36]. Reduction of Pd(II) to Pd(0) nanoparticles under reaction conditions was confirmed. In contrast to the first described case, in Suzuki-Miyaura reaction the size of Pd(0) nanoparticles was the same before and after the catalytic cycle. The catalytic activity of both palladium forms was quite high, however Pd(0) formed in situ was slightly more efficient as catalyst. In the third part of the article studies of palladium reduction in anionic complexes of [IL]2[PdX4] type are shown, where IL = imidazolium cation [37]. These complexes catalyzed well Suzuki-Miyaura cross-coupling, but they were not stable under reaction conditions and decomposed to Pd(0) nanoparticles and Pd black. Using ESI-MS method it was possible to identify polynuclear (Pd3, Pd5) intermediate forms, stabilized with imidazolium cations or N-heterocyclic carbenes. In all systems discussed in the article co-existence of Pd(0) nanoparticles and monomolecular complexes was observed. That is important for understanding of the nature of catalytically active forms in C-C bond forming reactions.
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