Ruthenium-catalyzed allylation reaction in ionic liquid (original) (raw)
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Ionic imidazolium containing ruthenium complexes and olefin metathesis in ionic liquids
Journal of Molecular Catalysis A-chemical, 2007
The preparation of two ionic Hoveyda's type catalysts with an ionic chain, containing an imidazolium salt tag link to the ortho oxygen atom (11) and to the meta-position (12) of the styrenylidene ligand is presented. The catalysts are evaluated in ionic liquid medium: the 1-butyl-3-methyl and 1-butyl-2,3-dimethyl imidazolium salts (bmim)+X− (X=PF6−, NTf2− (bistrifluoromethylsulfonimide)) for RCM of N,N-diallyltosylamide and dimethyldiallylmalonate. The
Catalysis Letters, 2000
The H 2 reduction of RuO 2 hydrate ''dissolved'' in 1-n-butyl-3-methylimidazolium ionic liquids with different counterions, hexafluorophosphate ðBMI Á PF 6 Þ, tetrafluoroborate ðBMI Á BF 4 Þ and trifluoromethane sulfonate ðBMI Á SO 3 CF 3 Þ, is a simple and reproducible method for the preparation of ruthenium nanoparticles of 2.0-2.5 nm diameter size and with a narrow size distribution. The Ru nanoparticles were characterized by TEM and XRD. The isolated Ru nanoparticles are reoxidized in air, whereas they are less prone to oxidation when imbibed in the ionic liquids. These nanoparticles are active catalysts for the solventless or liquid-liquid biphasic hydrogenation of olefins under mild reaction conditions (4 atm, 75 C). The catalytic system composed of nanoparticles dispersed in BMI Á PF 6 ionic liquid is very stable and can be reused several times without any significant loss in the catalytic activity. Total turnover numbers greater than 110 000 (based on total Ru) or 320 000 (corrected for exposed Ru atoms) were attained within 80 h for the hydrogenation of 1-hexene.
Ruthenium catalysts for selective nucleophilic allylic substitution
Pure and Applied Chemistry, 2008
Recent developments in the chemistry of η3-allylruthenium(IV) complexes are due to their straightforward synthesis resulting from oxidative addition of allylic substrates to a ruthenium(II) center. Subsequent reaction with a nucleophile is the basis of their involvement in the catalytic allylic substitution reaction. We focus here on ruthenium-catalyzed substitution of allylic substrates by C-, N-, and O-nucleophiles and show that selected ligands make regio- and enantioselective reactions possible.
2006
The catalytic activity of the bis(allyl)-ruthenium(IV) dimer [{Ru(η 3 :η 3 -C10H16)(µ-Cl)Cl}2] (C10H16 ) 2,7-dimethylocta-2,6-diene-1,8-diyl) (1), and that of its mononuclear derivatives [Ru(η 3 :η 3 -C10H16)Cl2(L)] (L ) CO, PR3, CNR, NCR) (2) and [Ru(η 3 :η 3 -C10H16)Cl(NCMe)2][SbF6] (3), in the redox isomerization of allylic alcohols into carbonyl compounds, both in tetrahydrofuran and in water, is reported. In particular, a variety of allylic alcohols have been quantitatively isomerized using [{Ru(η 3 :η 3 -C10H16)(µ-Cl)Cl}2] (1) as catalyst, the reactions proceeding in all cases faster in water. Remarkably, complex 1 has been found to be the most efficient catalyst reported to date for this particular transformation, leading to TOF and TON values up to 62 500 h -1 and 1 500 000, respectively. Moreover, catalyst 1 can be recycled and is capable of performing allylic alcohol isomerizations even in the presence of conjugated dienes, which are known to be strong poisons in isomerization catalysis. On the basis of both experimental data and theoretical calculations (DFT), a complete catalytic cycle for the isomerization of 2-propen-1-ol into propenal is described. The potential energy surfaces of the cycle have been explored at the B3LYP/6-311+G(d,p)// B3LYP/6-31G(d,p) + LAN2DZ level. The proposed mechanism involves the coordination of the oxygen atom of the allylic alcohol to the metal. The DFT energy profile is consistent with the experimental observation that the reaction only proceeds under heating. Calculations predict the catalytic cycle to be strongly exergonic, in full agreement with the high yields experimentally observed.
Advanced Synthesis & Catalysis, 2008
= Me) and [ruthenium(pentamethylcyclopentadiene)(2-quinolinecarboxylato)(1-n-propylallyl)] tetrafluoroborate (4'a), as allylruthenium(IV) complexes, have been synthesized in one step, starting from [ruthenium(R-substituted-tetramethylcyclopentadiene)tris(acetonitrile) hexafluorophosphate or tetrafluoroborate complexes, quinaldic acid, and allylic alcohols. Single stereoisomers are obtained and the X-ray single crystal structure determinations of 3b (R = t-Bu, R' = Me) and 4'a allow one to specify the preferred arrangement. Complexes 3a (R = R' = Me) and 3b are involved as precatalysts favoring the formation of branched products in regioselective nucleophilic allylic substitution reactions, starting from ethyl 2-(E)-hexen-1-yl carbonate and chlorohexene as unsymmetrical aliphatic allylic substrates. Phenols, dimethyl malonate, and primary (aniline) and secondary (pyrrolidine, piperidine) amines have been used as nucleophiles under mild basic conditions. For the first time, the regioselectivity in favor of the branched product obtained from purely aliphatic allylic substrates is close to the high regioselectivity previously reached starting from cinnamyl-type substrates in the presence of ruthenium catalysts.
Catalytic carbon dioxide transformation catalysed ruthenium in ionic liquids
2016
Catalytic CO2 transformation signified a paradigm shift towards the fabrication of contemporary chemical energy. The abundance of CO2 and the impendingstorageoffossilbuildingblocks,hasledtotheproposalthatCO2should be the C1-building block of the future. This doctoral thesis based on the developmentofanefficienthomogeneousRu-catalyticsysteminionicliquids,and its exploitation for Ru-catalyzed carbonylations reactions with CO2 as CO source. Primarily synthesized task-specific ionic Liquids for the generation of an active homogeneous Ru-catalytic system by reacting with Ru3(CO)12 precursor. Then reactionwasoptimizedfortheRu-catalyzedselectivehydroformylationofalkenes withCO2,andalsoinvestigatedthemechanisticinsight(Chapter-3).Thereaction of 1methyl3nbutylimidazolium chloride [BMI•Cl], or 1nbutyl2,3dimethyl
Biopolymer-Supported Ionic-Liquid-Phase Ruthenium Catalysts for Olefin Metathesis
ChemSusChem, 2014
Original ruthenium supported ionic liquid phase (SILP) catalysts based on alginates as supports were developed for olefin metathesis reactions. The marine biopolymer, which fulfills most of the requisite properties for a support such as widespread abundance, insolubility in the majority of organic solvents, a high affinity for ionic liquids, high chemical stability, biodegradability, low cost, and easy processing, was impregnated by [bmim][PF 6 ] containing an ionically tagged ruthenium catalyst. These biosourced catalysts show promising performances in ring-closing metathesis (RCM) and cross-metathesis (CM) reactions, with a high level of recyclability and reusability combined with a good reactivity.
Chemical Communications, 2011
All compounds were prepared under a purified argon atmosphere using standard Schlenk and vacuum-line techniques. The organic solvents were purified on MBraun solvent purification system-800 series. Ionic liquids IL1(1-butyl-3-methyl-imidazolium hexafluorophosphate) and IL2 (N-butyl-N-methyl pyrrolidinium bis-trifluoromethylsulfonylamide) were supplied by Solvionic and treated under vacuum at 60 °C overnight prior use. Other chemicals were used as purchased. The chiral carbohydrate-based diphosphite ligands (L1 and L2) were prepared following previously described methodology
Journal of the Brazilian Chemical Society, 2004
A reação de NaBH 4 com RuCl 3 dissolvido no líquido iônico 1-n-butil-3-metilimidazólio hexafluorfosfato (BMI.PF 6 ) é um método simples e reprodutível para a síntese de nanopartículas de RuO 2 estáveis com distribuição estreita e diâmetro da partícula entre 2-3 nm. As nanopartículas de RuO 2 foram caracterizadas por XRD, XPS, EDS e TEM. Estas nanopartículas mostraram alta atividade catalítica tanto na catálise heterogênea quanto na hidrogenação bifásica líquido-líquido de olefinas e arenos sob condições moderadas de reação. Experimentos de envenenamento com Hg(0) e CS 2 , e análises de XRD e TEM de partículas isoladas após a catálise indicaram a formação de nanopartículas de Ru(0). As nanopartículas podem ser reutilizadas em condições de catálise heterogênea até 10 vezes na hidrogenação de 1-hexeno rendendo um número total de ciclos catalíticos de 175.000 para átomos de Ru expostos.