198623-99-3Relevant academic research and scientific papers
Regio- and Stereoselective Dehydrogenative Silylation and Hydrosilylation of Vinylarenes Catalyzed by Ruthenium Alkylidenes
Bokka, Apparao,Jeon, Junha
, p. 5324 - 5327 (2016)
Development of regio- and stereoselective dehydrogenative silylation and hydrosilylation of vinylarenes with alkoxysilanes, catalyzed by ruthenium alkylidenes, is described. Varying L- and X-type ligands on ruthenium alkylidenes permits selective access to either (E)-vinylsilanes or β-alkylsilanes with high regio- and stereocontrol. cis,cis-1,5-Cyclooctadiene was identified as the most effective sacrificial hydrogen acceptor for the dehydrogenative silylation of vinylarenes, which allows use of a nearly equimolar ratio of alkenes and silanes.
The two faces of platinum hydrospirophosphorane complexes—Not only relevant catalysts but cytotoxic compounds as well
Skar?yńska, Anna,Kowalczyk, Marta,Majchrzak, Mariusz,Pi?tka, Marta,Augustyniak, Adam W.,Siczek, Mi?osz,W?odarczyk, Kinga,Simiczyjew, Aleksandra,Nowak, Dorota
, (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.
Manganese-Catalyzed Dehydrogenative Silylation of Alkenes following Two Parallel Inner-Sphere Pathways
Weber, Stefan,Glavic, Manuel,St?ger, Berthold,Pittenauer, Ernst,Podewitz, Maren,Veiros, Luis F.,Kirchner, Karl
supporting information, p. 17825 - 17832 (2021/11/04)
We report on an additive-free Mn(I)-catalyzed dehydrogenative silylation of terminal alkenes. The most active precatalyst is the bench-stable alkyl bisphosphine Mn(I) complex fac-[Mn(dippe)(CO)3(CH2CH2CH3)]. The catalytic process is initiated by migratory insertion of a CO ligand into the Mn-alkyl bond to yield an acyl intermediate which undergoes rapid Si-H bond cleavage of the silane HSiR3 forming the active 16e- Mn(I) silyl catalyst [Mn(dippe)(CO)2(SiR3)] together with liberated butanal. A broad variety of aromatic and aliphatic alkenes was efficiently and selectively converted into E-vinylsilanes and allylsilanes, respectively, at room temperature. Mechanistic insights are provided based on experimental data and DFT calculations revealing that two parallel reaction pathways are operative: an acceptorless reaction pathway involving dihydrogen release and a pathway requiring an alkene as sacrificial hydrogen acceptor.
Platinum(II) 1,2,4-Triazolin-5-ylidene Complexes: Stereoelectronic Influences on Their Catalytic Activity in Hydroelementation Reactions
Dang, Thanh Tuan,Huynh, Han Vinh,Nguyen, Hung Huy,Nguyen, Van Ha
, (2020/07/03)
Five platinum(II) 1,2,4-triazolin-5-ylidene (tazy) complexes of the general formula [PtCl2(DMSO)(R-tazy)] (1-5), bearing different N4 substituents (R = Dipp (1), Mes (2), Ph (3), Nap (4), and Bn (5)), have been successfully synthesized. The compounds have
[Rh(Cod)Cl]2/Pph3?catalyzed dehydrogenative silylation of styrene derivatives with NBE as a hydrogen acceptor
Li, Chengyang,Lu, Wenkui,Wu, Xiaoyu,Xie, Xiaomin,Zhang, Zhaoguo
, p. 3780 - 3788 (2020/11/23)
Direct synthesis of arylalkenylsilanes by [Rh(COD)Cl]2/ PPh3-catalyzed dehydrogenative silylation of styrene derivatives with R3SiH (R = alkyl, alkoxy, aryl) was realized, in which norbornene (NBE) and PPh3 play a key role in achieving excellent selectivity in the formation of dehydrogenative silylation products. Moreover, this high-yielding transformation exhibits a broad substrate scope and good functional group tolerance.
The cobalt(II) complex of a new tridentate Schiff-base ligand as a catalyst for hydrosilylation of olefins
Gorczyński, Adam,Zaranek, MacIej,Witomska, Samanta,Bocian, Aleksandra,Stefankiewicz, Artur R.,Kubicki, MacIej,Patroniak, Violetta,Pawlu?, Piotr
, p. 71 - 74 (2016/02/26)
Condensation of 1-methyl-2-imidazolecarboxaldehyde with 2-(1-methylhydrazinyl)pyridine results in the synthesis of new, tridentate Schiff-base ligand L, which readily reacts with CoCl2 to form a monometallic [CoLCl2] complex that, upon reduction, functions as active hydrosilylation catalyst. The ligand and the [CoLCl2] catalyst have been characterized spectroscopically (MS, NMR, FTIR) and by single crystal X-ray diffraction techniques. The results of preliminary catalytic experimentation show that the cobalt complex can induce hydrosilylation and dehydrogenative silylation of olefins, depending upon the hydrosilane substrate used.
Highly β-(E)-selective hydrosilylation of terminal and internal alkynes catalyzed by a (IPr)Pt(diene) complex
Berthon-Gelloz, Guillaume,Schumers, Jean-Marc,De Bo, Guillaume,Marko, Istvan E.
, p. 4190 - 4197 (2008/09/20)
(Chemical Equation Presented) The regioselective hydrosilylation of terminal and internal alkynes catalyzed by the novel (IPr)Pt(AE) (7) (IPr = bis(2,6-diisopropylphenyl)imidazo-2-ylidene, AE = allyl ether) complex is presented. The (IPr)Pt(AE) catalyst displays enhanced activity and regioselectivity for the hydrosilylation of terminal and internal alkynes with low catalyst loading (0.1 to 0.05 mol %) when compared to the parent (IPr)Pt(DVDS) complex (6) (DVDS = divinyltetramethyldisiloxane). The reaction leads to exquisite regioselectivity in favor of the cis-addition product on the less hindered terminus of terminal and internal alkynes. The solvent effects were examined for the difficult hydrosilylation of benzylpropargyl ether. In light of the observed product distribution and kinetic data, a mechanistic scheme is proposed involving two competing catalytic cycles. One cycle leads to high regioselectivities while the other, having lost the stereodirecting IPr carbene ligand, displays low regiocontrol and activities. The importance of this secondary catalytic cycle is either caused by the strong coordinating ability of the alkyne or by the low reactivity of the silane or both.
