17955-88-3Relevant articles and documents
Silacyclopropylideneplatinum(0) Complex as a Robust and Efficient Hydrosilylation Catalyst
Troadec, Thibault,Prades, Amparo,Rodriguez, Ricardo,Mirgalet, Raphael,Baceiredo, Antoine,Saffon-Merceron, Nathalie,Branchadell, Vicen?,Kato, Tsuyoshi
, p. 8234 - 8240 (2016)
The base-stabilized silacyclopropylidene 1 behaves as a versatile strongly nucleophilic ligand toward transition metals. The strong silylene-metal binding related to both increased σ-donating and π-accepting character of silylene 1 compared to N-heterocyc
Decoding catalytic activity of platinum carbene hydrosilylation catalysts
Meister, Teresa K.,Kück, Jens W.,Riener, Korbinian,P?thig, Alexander,Herrmann, Wolfgang A.,Kühn, Fritz E.
, p. 157 - 166 (2016)
A series of complexes of the formula [Pt(dvtms)(ImPy-R)] (dvtms = 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, ImPy-R = 2-R-imidazo[1,5-a]pyridine-3-ylidene; R = 4-cyanophenyl (4a), 4-trifluoromethylphenyl (4b), phenyl (4c), 4-methoxyphenyl (4d), mesityl (4
Developing a Highly Active Catalytic System Based on Cobalt Nanoparticles for Terminal and Internal Alkene Hydrosilylation
Jakoobi, Martin,Dardun, Vincent,Veyre, Laurent,Meille, Valérie,Camp, Clément,Thieuleux, Chloé
, p. 11732 - 11740 (2020)
This work describes the development of easy-To-prepare cobalt nanoparticles (NPs) in solution as promising alternative catalysts for alkene hydrosilylation with the industrially relevant tertiary silane 1,1,1,3,5,5,5-heptamethyltrisiloxane (MDHM). The Co NPs demonstrated high activity when used at 30 °C for 3.5-7 h in toluene, with catalyst loadings 0.05-0.2 mol %, without additives. Under these mild conditions, a set of terminal alkenes were found to react with MDHM, yielding exclusively the anti-Markovnikov product in up to 99% yields. Additionally, we demonstrated the possibility of using UV irradiation to further activate these cobalt NPs not only to enhance their catalytic performances but also to promote tandem isomerization-hydrosilylation reactions using internal alkenes, among them unsaturated fatty ester (methyl oleate), to produce linear products in up to quantitative yields.
Iron catalysts for selective anti-Markovnikov alkene hydrosilylation using tertiary silanes
Tondreau, Aaron M.,Atienza, Crisita Carmen Hojilla,Weller, Keith J.,Nye, Susan A.,Lewis, Kenrick M.,Delis, Johannes G. P.,Chirik, Paul J.
, p. 567 - 570 (2012)
Alkene hydrosilylation, the addition of a silicon hydride (Si-H) across a carbon-carbon double bond, is one of the largest-scale industrial applications of homogeneous catalysis and is used in the commercial production of numerous consumer goods. For decades, precious metals, principally compounds of platinum and rhodium, have been used as catalysts for this reaction class. Despite their widespread application, limitations such as high and volatile catalyst costs and competing side reactions have persisted. Here, we report that well-characterized molecular iron coordination compounds promote the selective anti-Markovnikov addition of sterically hindered, tertiary silanes to alkenes under mild conditions. These Earth-abundant base-metal catalysts, coordinated by optimized bis(imino)pyridine ligands, show promise for industrial application.
New approach to hydrosilylation reaction in ionic liquids as solvent in microreactor system
Kukawka,Pawlowska-Zygarowicz,Dutkiewicz,Maciejewski,Smiglak
, p. 61860 - 61868 (2016)
Continuous flow-through reactors on a micro scale (microreactors) are being investigated as a new approach to chemical synthesis, due to significantly larger surface-to-volume ratios and micro-structured internal volumes, which allow for much more efficient heat exchange. Functionalized siloxanes, as one of the most important classes of organosilicon compounds, are widely applied in industry. Many of their synthetic methods are based on the catalytic process of hydrosilylation. In our studies, we investigated, as a model, the reaction between 1,1,1,3,5,5,5-heptamethyltrisiloxane and 1-octene, using the Karstedt catalyst dissolved in seven different ionic liquids. The reaction was carried out in batch and in the microreactor system. Studies have shown that the use of ionic liquids in general allows for catalyst recycling and reuse in subsequent reaction cycles. Moreover, the use of microreactors intensified the process, allowing a higher yield to be obtained than when using conventional batch reactions.
Platinum-Catalyzed Alkene Hydrosilylation: Solvent-Free Process Development from Batch to a Membrane-Integrated Continuous Process
Bayrakdar, Tahani A. C. A.,Maliszewski, Benon P.,Nahra, Fady,Ormerod, Dominic,Nolan, Steven P.
, p. 3810 - 3814 (2021)
The integration of a membrane separation protocol with the platinum-catalyzed hydrosilylation of olefins is investigated. The catalytic reaction is first optimized in batch where [Pt(IPr*)(dms)Cl2] (IPr=1,3-bis[2,6-bis(diphenylmethyl)-4-methylphenyl]imidazol-2-ylidene, dms=dimethyl sulfide) demonstrates superior activity compared to the less sterically encumbered [Pt(SIPr)(dms)Cl2] (SIPr=1,3-bis(2,6-diisopropylphenyl)imidazolidine) congener. Filtration conditions are identified in membrane screening experiments. Hydrosilylation of 1-octene catalyzed by [Pt(IPr*)(dms)Cl2] is conducted in continuous mode and the platinum catalyst is separated efficiently over the commercially available Borsig oNF-2 membrane, all under solvent-free conditions. An advantage of this process is that both reaction and separation are coupled in a single step. Moreover, at the end of the process the intact catalyst was recovered in 80 % yield as an off-white solid without any further purification.
The effect of the morpholinium ionic liquid anion on the catalytic activity of Rh (or Pt) complex-ionic liquid systems in hydrosilylation processes
Jankowska-Wajda, Magdalena,D?bek, Izabela,Fiedorow, Ryszard,Maciejewski, Hieronim
, p. 26922 - 26927 (2018)
Studies were performed on the catalytic activity for olefin hydrosilylation shown by three rhodium complexes, [{Rh(μ-OSiMe3)(cod)}2] (I), [{Rh(μ-Cl)(cod)}2] (II) and [RhCl(PPh3)3] (III), and three platinum complexes, [Pt(PPh3)4] (IV), [Pt(PPh3)2Cl2] (V) and PtCl4 (VI), immobilized in a series of different anion-containing morpholinium ionic liquids. The effect of the kind of anion (its nucleophilic character) on the activity, stability and possibility of a catalytic system with multiple uses in the hydrosilylation process has been established. In the case of the best systems it was possible to reuse the same catalyst sample 10 times almost without any decrease in the activity and a TON value over 99?000 was obtained.
A family of rhodium(i) NHC chelates featuring O-containing tethers for catalytic tandem alkene isomerization-hydrosilylation
Srivastava, Ravi,Jakoobi, Martin,Thieuleux, Chloé,Quadrelli, Elsje Alessandra,Camp, Clément
, p. 869 - 879 (2021/02/03)
The rhodium complex Rh(HL)(COD)Cl, 1, L being a functionalized N-heterocyclic carbene (NHC) ligand with an oxygen-containing pendant arm, has been used as the entry point to synthesize a series of neutral and cationic Rh(i) O,C chelates. While the Rh-carbene interaction is similar in all these 16-electron complexes, structural analysis reveals that the strength of the Rh-O bond is greatly affected by the nature of the O-donor: R-O- > R-OH > R-OBF3. These subtle changes in the nature of the O-containing tether are found to be responsible for large differences in the alkene hydrosilylation catalytic activity of these compounds: the stronger the Rh-O interaction, the better the catalytic performances. The most active catalyst, [Rh(L)(COD)], 2, demonstrated good catalytic activity under mild reaction conditions for the hydrosilylation of a range of alkene substrates with the industrially relevant non-activated tertiary silane, 1,1,1,3,5,5,5-heptamethyltrisiloxane (MDHM). Furthermore, this complex is an effective catalyst for the selective remote functionalization of internal olefins at room temperature via tandem alkene isomerization-hydrosilylation.
The two faces of platinum hydrospirophosphorane complexes—Not only relevant catalysts but cytotoxic compounds as well
Augustyniak, Adam W.,Kowalczyk, Marta,Majchrzak, Mariusz,Nowak, Dorota,Pi?tka, Marta,Siczek, Mi?osz,Simiczyjew, Aleksandra,Skar?yńska, Anna,W?odarczyk, Kinga
, (2021/12/08)
Platinum complexes [PtCl2(L)] L = L1, L2 with symmetrical HP (OCH2CMe2NH)2 (L1) and unsymmetrical HP(OCMe2CMe2O)(OCH2CMe2NH) (L2) hydrospirophosphorane (HSP) ligands were demonstrated to play a dual role of catalysts and cytotoxic compounds as well. The structure of new complex [PtCl2(L2)] was confirmed by physicochemical and spectroscopic methods, as well as single X-ray diffraction studies for [PtCl2{P (OCMe2CMe2O)(OCH2CMe2NH2)}]. HSP ligand coordinated to the platinum center in bidentate κ2-P,NH2 chelating mode of fashion. Both complexes were found to exhibit catalytic activity for Heck cross-coupling reactions of iodobenzene with substituted styrenes, with good conversion and yield of stilbenes. Moreover, complexes have been applied as excellent catalysts for highly regioselective hydrosilylation of aromatic and aliphatic terminal olefins, and acetylenes terminal and internal as well. On the other hand, the preliminary biological studies revealed that in the presence of foretinib, drug candidate in clinical trials for the treatment of cancer, platinum complexes revealed increased synergistic effect and efficiently decreased the number of viable cells of triple negative breast cancer MDA-MB-231 cell line.
