- One-pot conversion of primary alcohols to α-oxygenated alkanals with tempo in combination with molecular oxygen and ruthenium complex
-
Reaction of primary alcohols with an oxidizing system composed of 4-BzOTEMPO (2 equiv.), RuCl2(PPh3)3 as a catalyst, and molecular oxygen leads to concomitant oxidation and substitution, giving the corresponding α-oxygenated alkanals. Similar reaction of secondary alcohols terminates at the stage of oxidation of hydroxyl group, forming the ketones, selectively.
- Inokuchi, Tsutomu,Nakagawa, Keiichi,Torii, Sigeru
-
-
Read Online
- β-Cyclodextrins modified by alkyl and poly(ethylene oxide) chains: A novel class of mass transfer additives for aqueous organometallic catalysis
-
A novel class of β-cyclodextrins (β-CDs) bearing alkyl chains on the secondary face and poly(ethylene oxide) chains on the primary face was synthesized. Their interactions with two water-soluble derivatives of triphenylphosphane were investigated by 31P{1H} and 1H NMR. Their behaviour in rhodium-catalysed biphasic hydroformylation of 1-decene was evaluated and the best result was obtained with a β-CD bearing methyl groups on the secondary face and poly(ethylene oxide) chains on the primary face. This CD appeared to be more efficient than randomly methylated β-CD which is currently one of the best mass transfer additives for hydroformylation.
- Badi, Nezha,Guégan, Philippe,Legrand, Fran?ois-Xavier,Leclercq, Lo?c,Tilloy, Sébastien,Monflier, Eric
-
-
Read Online
- Polyether phosphite for hydroformylation of higher olefins in non-aqueous system and catalyst recovery
-
A new rhodium catalyst recyling system for non-aqueous hydroformylation of 1-decene is described using a polyether phosphite, OPGPP with a polyether chain of over 19 ethylene glycol units. The corresponding rhodium complexes formed in situ are active for non-aqueous hydroformylation of 1-decene. The catalysts precipitated from the reaction mixture on cooling to room temperature or lower and were reused up to six times without obvious decrease in activity. P loss in the seventh reaction run was detected to be 0.92%. Complex OPGPP/Ru3(CO)3 formed in situ has also been proved to be a moderate catalyst for the non-aqueous hydroformylation of 1-decene. The catalysts retained considerable activity up to 87.1% after four successive reaction runs.
- Liu, Xiaozhong,Li, Hongmei,Wang, Yanhua,Jin, Zilin
-
-
Read Online
- Continuous hydroformylation of 1-decene in an aqueous biphasic system enabled by methylated cyclodextrins
-
For the first time, randomly methylated β-cyclodextrin was applied as the mass transfer agent in a continuous process. Considering the example of the Rh-catalyzed hydroformylation of 1-decene, process development was shown, where cyclodextrin was used together with a catalyst system that was continuously recovered and recycled using an aqueous biphasic system. In initial experiments, water-soluble and commercially available Rh/TPPTS and Rh/sulfoxantphos catalyst systems were scaled up from 50 ml into 1000 ml high-pressure autoclave systems to demonstrate their scalability. Both these systems were compared, and they afforded excellent chemoselectivity (>99percent) toward the desired linear aldehyde product. In particular, higher regioselectivity (up to 31) was achieved for the Rh/sulfoxantphos system. Investigations regarding the long-term stability of the mass transfer agent and both catalyst systems were carried out in a continuously operated miniplant process. It was shown that the process could be successfully operated under the steady state for over 200 h with chemoselectivity of >97percent toward the desired aldehyde product. Simultaneously, extremely low Rh leaching (total: 0.59percent) was observed over the entire period of 200 h.
- Dreimann, J. M.,Künnemann, K. U.,Lange, D.,Monflier, E.,Schurm, L.,Seidensticker, T.,Tilloy, S.,Vogt, D.
-
-
Read Online
- TEMPO radical polymer grafted silicas as solid state catalysts for the oxidation of alcohols
-
TEMPO polymer-grafted silicas were synthesized by "grafting from" and "grafting to" methods using RAFT polymerization, and their catalytic activities as a new class of solid state catalyst for oxidation reactions with alcohols demonstrated.
- Saito, Kei,Hirose, Koji,Okayasu, Teruyuki,Nishide, Hiroyuki,Hearn, Milton T. W.
-
-
Read Online
- Rhodium-BiPhePhos catalyzed hydroformylation studied by operando FTIR spectroscopy: Catalyst activation and rate determining step
-
The homogeneously rhodium catalyzed hydroformylation of 1-decene was studied using operando FTIR spectroscopy. The bulky chelating diphosphite ligand BiPhePhos was used for catalyst modification. Special emphasis was given to the transformation of the Rh-precursor Rh(acac)(CO)2 to the activated HRh(BiPhePhos)(CO)2 catalyst. Under hydroformylation conditions, this complex was found to be the most abundant catalyst species over a wide range of olefin conversion. Other inactive or non-selective rhodium species were not detectable. Analysis of the turnover frequency revealed a first order dependence of the hydroformylation rate with respect to the concentration of 1-decene. These findings indicate that the coordination of the olefin to the Rh-BiPhePhos catalyst is determining the hydroformylation rate of 1-decene.
- J?rke, Andreas,Seidel-Morgenstern, Andreas,Hamel, Christof
-
-
Read Online
- Rhodium catalyzed hydroformylation of 1-decene in low melting mixtures based on various cyclodextrins and N,N′-dimethylurea
-
Different low melting mixtures (LMMs) based on N,N′-dimethylurea (DMU) and various cyclodextrin (CD) derivatives were synthetized. The melting point was weakly affected by the size and the chemical modification of CD. By contrast, the chemical modification of CD led to a decrease in viscosity of the LMMs. These mixtures were evaluated as solvent in rhodium-catalyzed hydroformylation reaction of 1-decene. The LMM based on DMU/RAME-β-CD (70/30) allowed reaching the highest catalytic activity (1980 h- 1). The influence of several factors was studied and it was established that the conversion increased with the 1-decene solubility and decreased with the LMM viscosity.
- Ferreira, Michel,Jér?me, Fran?ois,Bricout, Hervé,Menuel, Stéphane,Landy, David,Fourmentin, Sophie,Tilloy, Sébastien,Monflier, Eric
-
-
Read Online
- A New Oxidizing System for Aromatic Alcohols by the Combination of N-Oxoammonium Salt and Electrosynthesized Tetraalkylammonium Tribromide
-
A combination of 2,2,6,6-tetramethyl-1-piperidinyloxyl and tetraalkylammonium tribromides (R4NBr3), which are available from the corresponding tetraalkylammonium bromides via electrooxidation with potassium bromide, has proved to be useful for oxidations of primary and secondary alcohols to the corresponding aldehydes and ketones, respectively.The oxidation reaction proceeds smoothly even with a 0.5-1.0 molpercent of N-oxyl compounds and 1.5-2.0 equivalents of tetraalkylammonium tribromides in an aqueous-organic two-phase solution buffered at pH 8.0-8.6.This recyclable oxidant/co-oxidant combination system may involve the formation of N-oxoammonium salts, actual oxidizing agents of alcohols, by the action of hypobromite species generated from R4NBr3 in the binary solution.Utility of the method is highlighted by the selective oxidation of benzylic alcohols bearing electron-releasing groups on the aromatic nucleus to the corresponding aldehydes or ketones without any bromination and overoxidation.
- Inokuchi, Tsutomu,Matsumoto, Sigeaki,Fukushima, Mitsuhiro,Torii, Sigeru
-
-
Read Online
- Low melting mixtures based on β-cyclodextrin derivatives and N,N′-dimethylurea as solvents for sustainable catalytic processes
-
β-Cyclodextrin series and N,N′-dimethylurea formed low melting mixtures able to immobilize organometallic species based on sulfonated phosphanes. Hydroformylation and Tsuji-Trost reactions were efficiently performed in these new solvents which led to new recyclable catalytic systems. This journal is the Partner Organisations 2014.
- Jerome, Francois,Ferreira, Michel,Bricout, Herve,Menuel, Stephane,Monflier, Eric,Tilloy, Sebastien
-
-
Read Online
- Cetyltrimethylammonium bromochromate: A new and efficient oxidant for organic substrates
-
Cetyltrimethylammonium bromochromate is a versatile reagent for the effective and selective oxidation of organic substrates, particularly for alcohols, under mild conditions. Copyright Taylor & Francis Group, LLC.
- Ghammamy, Shahriar,Eimanieh, Hossein,Mohammady, Mohammad Kazem
-
-
Read Online
- New nortriterpenoid and ceramides from stems and leaves of cultivated Triumfetta cordifolia a rich (Tiliaceae)
-
To highlight the role of plants in traditional healing, the leaves and the stems of cultivated Triumfetta cordifolia were phytochemically studied yielding a new nor- ursane type (1), a new ceramide (2) and a new piperidinic ceramide derivative (3) named, respectively, 2α,19α-dihy-droxy-3-oxo-23-nor- urs-12-en-28-oic acid, (2R)-2-hydroxy- N-[(2S,3S,4R,26E)-1,3,4-trihydroxy-26- triaconten-2-yl] tetradecanamide and (2R,8Z)-2-hydroxy-{(2S,3R,5R,6S)- 3,5-dihydroxy-6-[(1E,5Z)-hexadeca-1,5-dienyl]-2-(β-D-glu- copyranosyloxy)methyl piperidine-1-yl} tetracos-8-enamide (3). These were obtained together with lupeol (4), stigmasterol (5), 3-O-β-D- glucopyranoside of β-sitosterol (6), tormentic acid (7) from stems and heptadecanoic acid (8), β-carotene (9), oleanolic acid (10), and 24-hydroxy- tormentic acid (11 ) from leaves. The structures were determined on the basis of NMR data (1H-, 13C-, 2D-NMR analyses), mass spectrometry and confirmed by chemical transformations as well as comparison of spectral data with those reported in the literature. The FRAP method was used to evaluate the antioxidant activity of fractions collected from flash chromatography and isolated compounds. Among the fractions, four reduced Fe -TPTZ to Fe -TPTZ while isolated pure compounds showed no activity. AOCS 2010.
- Sandjo, Louis Pergaud,Tchoukoua, Abdou,Ntede, Hippolyte Nga,Yemloul, Mehdi,Perspicace, Enrico,Keumedjio, Felix,Couty, Francois,Kirsch, Gilbert,Ngadjui, Bonaventure Tchaleu
-
-
Read Online
- Rhodium complexes non-covalently bound to cyclodextrins: Novel water-soluble supramolecular catalysts for the biphasic hydroformylation of higher olefins
-
A new class of cationic α-cyclodextrins bearing 2-hydroxy-3-trime- thylammoniopropyl groups has been synthesised. We investigated their efficiency as mass-transfer promoters in a biphasic hydroformylation reaction catalysed by a rhodium trisulfonated triphenylphosphine system. These cationic α-cyclodextrins greatly increased the reaction rate, the chemoselectivity, and, surprisingly, the linear-to-branched aldehyde ratio. We attributed this unexpected enhancement of the linear-to-branched aldehyde ratio to the in situ formation of new catalytic supramolecular species obtained by ion-exchange between the catalyst ligand and the cationic α-cyclodextrins.
- Sueur, Benoit,Leclercq, Loic,Sauthier, Mathieu,Castanet, Yves,Mortreux, Andre,Bricout, Herve,Tilloy, Sebastien,Monflier, Eric
-
-
Read Online
- Polyether phosphine oxide induced phase separable homogeneous catalysis for hydroformylation of higher olefins
-
Triarylphosphine oxide bearing polyether group (PETAPO) gives high activity and allows easy separation of the catalyst for hydroformylation of 1-decene. PETAPO induces phase separable homogeneous catalysis for aqueous organic biphasic and nonaqueous hydroformylation reaction.
- Xiaozhong, Liu,Hongmei, Li,Fanzhi, Kong
-
-
Read Online
- Water-soluble triphenylphosphane-3,3′,3″-tricarboxylate (m-TPPTC) ligand and methylated cyclodextrins: A new combination for biphasic rhodium-catalyzed hydroformylation of higher olefins
-
The methylated cyclodextrins/m-TPPTC [tris(m-carboxyphenyl)phosphane trilithium salt] couples proved to be more efficient than the well-known methylated cyclodextrins/TPPTS [tris(m-sulfonatophenyl)phosphane trisodium salt] systems in terms of activities and selectivities to perform the Rh-catalyzed hydroformylation of higher olefins in an aqueous-organic system. The interactions cyclodextrins/m-TPPTC have been fully studied by NMR spectroscopy.
- Tilloy, Sebastien,Genin, Emilie,Hapiot, Frederic,Landy, David,Fourmentin, Sophie,Genet, Jean-Pierre,Michelet, Veronique,Monflier, Eric
-
-
Read Online
- Remarkable Effect of the Wavelength in the Photoassisted Carbonylation of the C-H Bond of Decane in the Presence of RhCl(CO)PR3)2 as the Catalyst
-
RhCl(CO)(Pr3)2-catalyzed and photoassisted carbonylation of decane leading to the formation of C11 aldehydes and/or 1-nonene was remarkably affected by the wavelength; irradiation with λ > 295 nm was essential to the formation of 1-nonene and undecanal.By cutting off λ 325 nm, 1-nonene formation was completely suppressed, and a series of isomeric C11 aldehydes were obtained.
- Sakakura, Toshiyasu,Sasaki, Koushi,Tokunaga, Yuko,Wada, Keisuke,Tanaka, Masato
-
-
Read Online
- Kinetics of hydroformylation of 1-decene using carbon-supported ossified HRh(CO)(TPPTS)3 catalyst
-
The kinetics of hydroformylation of 1-decene has been investigated using a carbon-supported ossified HRh(CO)(TPPTS)3/Ba catalyst in a temperature range of 343–363?K. The effect of concentration of 1-decene, catalyst loading, partial pressure of H2 and CO, and stirring speed on the reaction rate has been investigated. A first-order dependence was observed for catalyst concentration and hydrogen partial pressure. The rate showed a typical case of substrate inhibition for high 1-decene concentration. The rate varied with a linear dependence on PCO up to a CO partial pressure of 5–6?MPa in contrast to the general trends; for most of the rhodium-phosphine catalyzed hydroformylation reactions, severe inhibition of rate is observed with an increase in CO pressure. A rate equation has been proposed, which was found to be in good agreement with the observed rate data within the limit of experimental errors. The kinetic parameters and activation energy values have been reported.
- Pagar, Nitin S.,Deshpande, Raj M.
-
-
Read Online
- Reaction paths in the titanium dioxide photocatalysed degradation of dodecane and some of its derivatives
-
The photocatalytic oxidation of dodecane and some of its derivatives (C12H26, 1; C10H21CH=CH2, 2; C12H25SH, 3; C12H25OH, 4; C12H25NH2, 5; C11H23CHO, 6) has been studied in air-equilibrated aqueous TiO2 suspensions. The distribution of the intermediate products has been monitored during the degradation. C1-C12 Monocarboxylic acids are formed in all cases, though in a low yield with substrates 1-3. With compounds 4-6, acids are formed in a higher yield (>45%), initially including a large proportion of dodecanoic acid and are accompanied by significant amounts of aldehydes and alcohols. Relative efficiencies vary over a factor of 300 from 1 to 5 and a lower limit for the quantum yield is 1.18 for the latter compound, suggesting participation of a chain process. The data suggest that alkylperoxyl radicals are formed through initial hydrogen abstraction on the photocatalyst surface and oxygen addition and their reactivity with the starting reagent determines the course of the reaction. Activated substrates such as compounds 5 and 6, and to a lesser degree 4, easily transfer a hydrogen from position 1.
- Sturini, Michela,Soana, Federica,Albini, Angelo
-
-
Read Online
- Cyclodextrin/amphiphilic phosphane mixed systems and their applications in aqueous organometallic catalysis
-
When mixed with a water-soluble phosphane capable of self-assembling into micelles, native or modified β-cyclodextrins (β-CDs) show very contrasting behavior depending on their neutral or ionic nature. In the post-micellar region, neutral β-CDs led to a micelle destructuring. Conversely, micelles remained stable over a well-defined range of ionic β-CD concentrations. In that case, the micelle destruction was only observed when using a large excess of ionic β-CDs. The catalytic performances of these micellar systems have been evaluated in a rhodium-catalyzed hydroformylation reaction of 1-decene. We showed that, using ionic β-CDs, the catalytic activity could be improved without a detrimental impact upon the regioselectivity. A linear/branched aldehyde ratio as high as 8.6 could be achieved. The best results were obtained with stoichiometric quantities of ionic randomly methylated β-CDs with respect to the phosphane with a beneficial effect on the decantation at the end of the reaction. Copyright
- Ferreira, Michel,Bricout, Herve,Azaroual, Nathalie,Landy, David,Tilloy, Sebastien,Hapiot, Frederic,Monflier, Eric
-
-
Read Online
- Aqueous biphasic hydroformylation in the presence of cyclodextrins mixtures: Evidence of a positive synergistic effect
-
Mixtures of randomly methylated cyclodextrins of various sizes have been evaluated in the rhodium-catalysed hydroformylation of higher olefins in an aqueous biphasic medium. A marked positive non-linear effect on 1-tetradecene conversion is observed when the CD molar ratio in the mixture is modified. The formation of 2:1 ternary inclusion complexes between RAME-CDs and the olefin is supposed to be responsible for the extra conversion observed. The Royal Society of Chemistry.
- Ferreira, Michel,Legrand, Francois-Xavier,MacHut, Cecile,Bricout, Herve,Tilloy, Sebastien,Monflier, Eric
-
-
Read Online
- Rhodium catalyzed hydroformylation assisted by cyclodextrins in biphasic medium: Can sulfonated naphthylphosphanes lead to active, selective and recyclable catalytic species?
-
New sulfonated naphthylphosphanes having an average sulfonation degree around 2 have been synthetized and tested as ligand in the aqueous biphasic Rh-catalyzed hydroformylation of 1-decene assisted by randomly methylated β-cyclodextrins. All these water-soluble phosphanes associated to a rhodium precursor were able to perform aqueous hydroformylation of 1-decene. The best results in terms of catalyst recovery and recycling were obtained with sulfonated 2-naphthylphosphanes. With sulfonated 1-naphthylphosphanes, formation of low-coordinated catalytic species leading to a catalyst leaching in the organic phase was postulated. These results were rationalized by considering that sulfonated 1-naphthylphosphanes are bulkier ligands than sulfonated 2-naphthylphosphanes.
- Elard, Maxime,Denis, Julien,Ferreira, Michel,Bricout, Hervé,Landy, David,Tilloy, Sébastien,Monflier, Eric
-
-
Read Online
- Pillar5arenes as Supramolecular Hosts in Aqueous Biphasic Rhodium-Catalyzed Hydroformylation of Long Alkyl-chain Alkenes
-
Aqueous biphasic catalysis continues to attract strong interest, especially when very hydrophobic substrates are concerned. Indeed, their insolubility in water strongly limit their transformation by water-soluble organometallic catalysts. To improve contacts between the substrate-containing organic phase and the catalyst-containing phase, one of the best solutions consists in using interfacial additives capable of supramolecularly recognize the substrate and/or the catalyst. In the present study, modified pillar5arenes are considered as interfacial additives and their performance is assessed in Rh-catalyzed hydroformylation of long alkyl-chain alkenes (higher olefins). Pillar5arenes substituted by carboxylate functions and methyl groups P5 A-(Me)10-x-(CH2COOMe)x are compared to pillar5arenes substituted by polyethylene glycol (PEG) chains (P5 A-(Me)5-(PEG)5 and P5 A-(PEG)10). Utilization of P5 A-(Me)10-x-(CH2COOMe)x leads to high conversion and regioselectivity (linear/branched aldehyde ratio) in Rh-catalyzed hydroformylation of 1-decene and 1-hexadecene. Compared with other interfacial additives such as modified cyclodextrins, the studied pillar5arenes show lower chemo-selectivity, similar catalytic activity and higher regioselectivity.
- Benatmane, Missipssa,Cousin, Kévin,Laggoune, Nérimel,Menuel, Stéphane,Monflier, Eric,Woisel, Patrice,Hapiot, Frédéric,Potier, Jonathan
-
-
Read Online
- Reactivity of TEMPO anion as a nucleophile and its applications for selective transformations of haloalkanes or acyl halides to aldehydes
-
Sodium 2,2,6,6-tetramethylpiperidine-N-oxide (TEMPO-Na +), generated by reduction of TEMPO·with sodium naphthalenide in THF, reacted with alkyl halides or acyl halides to produce O-alkylated or acylated TEMPOs, which were in turn oxidized with mCPBA or reduced with DIBAL-H to afford the corresponding aldehydes, thus accomplishing a new protocol for the halides-carbonyls conversion. Graphical Abstract
- Inokuchi, Tsutomu,Kawafuchi, Hiroyuki
-
-
Read Online
- Polymer-supported nitroxyl radical catalyst for selective aerobic oxidation of primary alcohols to aldehydes
-
PS-TEMPO, a polymer-supported 2,2,6,6-tetramethyl-piperidine-N-oxyl (TEMPO), was successfully applied as a recyclable, active and selective catalyst for the oxidation of primary aliphatic and benzylic alcohols to aldehydes by molecular oxygen in the presence of Co(NO3)2 and Mn(NO3)2 as co-catalysts. The Royal Society of Chemistry 2005.
- Gilhespy, Michelle,Lok, Martin,Baucherel, Xavier
-
-
Read Online
- Two-phase hydroformylation of higher olefins using randomly methylated α-cyclodextrin as mass transfer promoter: A smart solution for preserving the intrinsic properties of the rhodium/trisulfonated triphenylphosphine catalytic system
-
The two-phase hydroformylation of higher olefins with the rhodium/trisulfonated triphenylphosphine catalytic system in the presence of various chemically modified α-cyclodextrins has been investigated. These cyclodextrins allowed us to increase greatly the reaction rate and the chemoselectivity of the reaction but, contrary to what has been observed previously with the chemically modified β-cyclodextrins, the linear to branched aldehydes ratio was not affected by the presence of α-cyclodextrin derivatives. Indeed, the latter was found to be similar to that obtained without any mass transfer promoter, suggesting that the catalytic species are stable in the presence of α-cyclodextrin derivatives.
- Leclercq, Loic,Sauthier, Mathieu,Castanet, Yves,Mortreux, Andre,Bricout, Herve,Monflier, Eric
-
-
Read Online
- Catalytic mechanism of a heme and tyrosyl radical-containing fatty acid α-(di)oxygenase
-
The steady-state catalytic mechanism of a fatty acid α-(di)oxygenase is examined, revealing that a persistent tyrosyl radical (Tyr379 ?) effects O2 insertion into Cα-H bonds of fatty acids. The initiating Cα-H homolysis step is characterized by apparent rate constants and deuterium kinetic isotope effects (KIEs) that increase hyperbolically upon raising the concentration of O 2. These results are consistent with H? tunneling, transitioning from a reversible to an irreversible regime. The limiting deuterium KIEs increase from ~30 to 120 as the fatty acid chain is shortened from that of the native substrate. In addition, activation barriers increase in a manner that reflects decreased fatty acid binding affinities. Anaerobic isotope exchange experiments provide compelling evidence that Tyr379 ? initiates catalysis by H? abstraction. C α-H homolysis is kinetically driven by O2 trapping of the α-carbon radical and reduction of a putative peroxyl radical intermediate to a 2(R)-hydroperoxide product. These findings add to a body of work which establishes large-scale hydrogen tunneling in proteins. This particular example is novel because it involves a protein-derived amino acid radical.
- Mukherjee, Arnab,Angeles-Boza, Alfredo M.,Huff, Gregory S.,Roth, Justine P.
-
-
Read Online
- Microbial biosynthesis of medium-chain 1-alkenes by a nonheme iron oxidase
-
Aliphatic medium-chain 1-alkenes (MCAEs, ~10 carbons) are "drop-in" compatible next-generation fuels and precursors to commodity chemicals. Mass production of MCAEs from renewable resources holds promise for mitigating dependence on fossil hydrocarbons. An MCAE, such as 1-undecene, is naturally produced by Pseudomonas as a semivolatile metabolite through an unknown biosynthetic pathway. We describe here the discovery of a single gene conserved in Pseudomonas responsible for 1-undecene biosynthesis. The encoded enzyme is able to convert medium-chain fatty acids (C10-C14) into their corresponding terminal olefins using an oxygen-activating, nonheme iron-dependent mechanism. Both biochemical and X-ray crystal structural analyses suggest an unusual mechanism of β-hydrogen abstraction during fatty acid substrate activation. Our discovery unveils previously unidentified chemistry in the nonheme Fe(II) enzyme family, provides an opportunity to explore the biology of 1-undecene in Pseudomonas, and paves the way for tailored bioconversion of renewable raw materials to MCAE-based biofuels and chemical commodities.
- Rui, Zhe,Li, Xin,Zhu, Xuejun,Liu, Joyce,Domigan, Bonnie,Barr, Ian,Cate, Jamie H. D.,Zhang, Wenjun
-
-
Read Online
- Rhodium phosphino-enolate complexes as chemo- and regioselective catalysts for the hydroformylation of styrenes
-
The catalytic utility of [κ2-{3-iPr 2P-2-O-indene}Rh(COD)] (COD = η4-1,5-cyclooctadiene) 1a in the hydroformylation of styrenes was examined. Complex 1a was shown to be an effective pre-catalyst in benzene and tetrahydrofuran, exhibiting good conversions to aldehyde and high branched o-linear selectivity for styrene, 4-chlorostyrene, and 4-methylstyrene under reasonably mild conditions (1000 psi syngas; 1.8 mol% Rh, 45 °C, 2-5 h). Under analogous conditions, the iridium congener of 1a proved inactive for hydroformylation. The synthesis and crystallographic characterization of the new complex [κ2-{2- iPr2PC6H4O}Rh(COD)] 2 is also reported; the catalytic performance of 2 in the hydroformylation of styrene was found to be comparable to that of 1a under similar catalytic conditions. We report herein on the use of rhodium phosphino-enolate complexes as effective pre-catalysts for the hydroformylation of styrene substrates, exhibiting high branched o-linear selectivity under relatively mild conditions.
- Uh, Yoon-Seo,Boyd, Alaina,Little, Vanessa R.,Jessop, Philip G.,Hesp, Kevin D.,Cipot-Wechsler, Judy,Stradiotto, Mark,McDonald, Robert
-
-
Read Online
- Heptakis(2,3-di-O-methyl-6-O-sulfopropyl)-β-cyclodextrin: A genuine supramolecular carrier for aqueous organometallic catalysis
-
The behavior of heptakis(2,3-di-O-methyl-6-O-sulfopropyl)-β- cyclodextrin as inverse phase transfer catalyst in biphasic Tsuji-Trost and hydroformylation reactions has been investigated. In terms of activity, this methylated sulfopropyl ether β-cyclodextrin is much more efficient than the randomly methylated β-cyclodextrin, which was the most active cyclodextrin known to date. From a selectivity point of view, the intrinsic properties of the catalytic system are fully preserved in the presence of this cyclodextrin as the chemo- or regioselectivity was found to be identical to that observed without a mass transfer promoter in the hydroformylation reaction. The efficiency of this cyclodextrin was attributed to its high surface activity and to the absence of interactions with the catalytically active species and the water-soluble phosphane used to dissolve the organometallic catalyst in the aqueous phase.
- Kirschner,Green,Hapiot,Tilloy,Leclercq,Bricout,Monflier
-
-
Read Online
- Catalyst composition containing bidentate phosphine ligand and application thereof
-
The catalyst composition comprises a bidentate phosphine ligand and a rhodium complex, wherein the skeleton of the bidentate phosphine ligand not only has C. 2 The symmetry and the appropriate rigidity, and the phosphine ligand derived based on the skeleton can provide effective steric hindrance around the catalyst center metal, so that the selectivity of the catalyst can be remarkably improved, the aldehyde yield is not lower 92% when the catalyst combination is applied to the hydroformylation reaction, and the selectivity of n-aldehyde is not lower 90%. In addition, the raw materials olefins with different structures can obtain outstanding reaction rate and normal aldehyde selectivity as compared with the existing catalyst systems, and can be suitable for the hydroformylation reaction of more types of olefins.
- -
-
Paragraph 0068; 0077-0080
(2021/11/03)
-
- Multicatalytic approach to one-pot stereoselective synthesis of secondary benzylic alcohols
-
One-pot procedures bear the potential to rapidly build up molecular complexity without isolation and purification of consecutive intermediates. Here, we report multicatalytic protocols that convert alkenes, unsaturated aliphatic alcohols, and aryl boronic acids into secondary benzylic alcohols with high stereoselectivities (typically >95:5 er) under sequential catalysis that integrates alkene cross-metathesis, isomerization, and nucleophilic addition. Prochiral allylic alcohols can be converted to any stereoisomer of the product with high stereoselectivity (>98:2 er, >20:1 dr).
- Casnati, Alessandra,Lichosyt, Dawid,Lainer, Bruno,Veth, Lukas,Dydio, Pawe?
-
supporting information
p. 3502 - 3506
(2021/05/10)
-
- Unexpected Reactions of α,β-Unsaturated Fatty Acids Provide Insight into the Mechanisms of CYP152 Peroxygenases
-
CYP152 peroxygenases catalyze decarboxylation and hydroxylation of fatty acids using H2O2 as cofactor. To understand the molecular basis for the chemo- and regioselectivity of these unique P450 enzymes, we analyze the activities of three CYP152 peroxygenases (OleTJE, P450SPα, P450BSβ) towards cis- and trans-dodecenoic acids as substrate probes. The unexpected 6S-hydroxylation of the trans-isomer and 4R-hydroxylation of the cis-isomer by OleTJE, and molecular docking results suggest that the unprecedented selectivity is due to OleTJE’s preference of C2?C3 cis-configuration. In addition to the common epoxide products, undecanal is the unexpected major product of P450SPα and P450BSβ regardless of the cis/trans-configuration of substrates. The combined H218O2 tracing experiments, MD simulations, and QM/MM calculations unravel an unusual mechanism for Compound I-mediated aldehyde formation in which the active site water derived from H2O2 activation is involved in the generation of a four-membered ring lactone intermediate. These findings provide new insights into the unusual mechanisms of CYP152 peroxygenases.
- Jiang, Yuanyuan,Li, Shengying,Li, Zhong,Peng, Wei,Tang, Dandan,Wang, Binju,You, Cai,Zhao, Yue
-
supporting information
p. 24694 - 24701
(2021/10/14)
-
- Selective Production of Linear Aldehydes and Alcohols from Alkenes using Formic Acid as Syngas Surrogate
-
Performing carbonylation without the use of carbon monoxide for high-value-added products is an attractive yet challenging topic in sustainable chemistry. Herein, effective methods for producing linear aldehydes or alcohols selectively with formic acid as both carbon monoxide and hydrogen source have been described. Linear-selective hydroformylation of alkenes proceeds smoothly with up to 88 % yield and >30 regioselectivity in the presence of single Rh catalyst. Strikingly, introducing Ru into the system, the dual Rh/Ru catalysts accomplish efficient and regioselective hydroxymethylation in one pot. The present processes utilizing formic acid as syngas surrogate operate simply under mild condition, which opens a sustainable way for production of linear aldehydes and alcohols without the need for gas cylinders and autoclaves. As formic acid can be readily produced via CO2 hydrogenation, the protocols represent indirect approaches for chemical valorization of CO2.
- Chen, Junjun,Hua, Kaimin,Liu, Xiaofang,Deng, Yuchao,Wei, Baiyin,Wang, Hui,Sun, Yuhan
-
p. 9919 - 9924
(2021/05/31)
-
- Atomically dispersed Rh on hydroxyapatite as an effective catalyst for tandem hydroaminomethylation of olefins
-
Tandem hydroaminomethylation is an efficient and green route for one-pot synthesis of amines directly from olefins. Herein, heterogeneous hydroxyapatite (HAP) supported single-atom Rh catalyst was prepared and used for tandem hydroaminomethylation of olefins. Characterization techniques confirmed the atomic dispersion of Rh species on HAP. Up to 99% conversion of 1-hexene with high selectivity to the desired amines (93.2%) was obtained over 0.5Rh1/HAP catalyst. Mechanism study demonstrated that the first hydroformylation step during the tandem catalytic process was rate-determining. Compared with the Rh nanoparticles on other oxide supports (Mg3Al, MgO and Al2O3), the atomically dispersed Rh sites on HAP ensured the high hydroformylation activity, thereby guaranteed the outstanding catalytic performance for the total tandem process. Furthermore, various corresponding amines can be obtained with satisfactory yields over 0.5Rh1/HAP catalyst from a wide scope of olefins or amines substrates.
- Gun, Gong,Li, Liusha,Li, Xiao,Lin, Tiejun,Qin, Tingting,Zhong, Liangshu
-
-
- Chemo- And regioselective hydroformylation of alkenes with CO2/H2over a bifunctional catalyst
-
As is well known, CO2 is an attractive renewable C1 resource and H2 is a cheap and clean reductant. Combining CO2 and H2 to prepare building blocks for high-value-added products is an attractive yet challenging topic in green chemistry. A general and selective rhodium-catalyzed hydroformylation of alkenes using CO2/H2 as a syngas surrogate is described here. With this protocol, the desired aldehydes can be obtained in up to 97% yield with 93/7 regioselectivity under mild reaction conditions (25 bar and 80 °C). The key to success is the use of a bifunctional Rh/PTA catalyst (PTA: 1,3,5-triaza-7-phosphaadamantane), which facilitates both CO2 hydrogenation and hydroformylation. Notably, monodentate PTA exhibited better activity and regioselectivity than common bidentate ligands, which might be ascribed to its built-in basic site and tris-chelated mode. Mechanistic studies indicate that the transformation proceeds through cascade steps, involving free HCOOH production through CO2 hydrogenation, fast release of CO, and rhodium-catalyzed conventional hydroformylation. Moreover, the unconventional hydroformylation pathway, in which HCOOAc acts as a direct C1 source, has also been proved to be feasible with superior regioselectivity to that of the CO pathway.
- Hua, Kaimin,Liu, Xiaofang,Wei, Baiyin,Shao, Zilong,Deng, Yuchao,Zhong, Liangshu,Wang, Hui,Sun, Yuhan
-
supporting information
p. 8040 - 8046
(2021/11/01)
-
- Binuclear Pd(I)-Pd(I) Catalysis Assisted by Iodide Ligands for Selective Hydroformylation of Alkenes and Alkynes
-
Since its discovery in 1938, hydroformylation has been thoroughly investigated and broadly applied in industry (>107 metric ton yearly). However, the ability to precisely control its regioselectivity with well-established Rh- or Co-catalysts has thus far proven elusive, thereby limiting access to many synthetically valuable aldehydes. Pd-catalysts represent an appealing alternative, yet their use remains sparse due to undesired side-processes. Here, we report a highly selective and exceptionally active catalyst system that is driven by a novel activation strategy and features a unique Pd(I)-Pd(I) mechanism, involving an iodide-assisted binuclear step to release the product. This method enables β-selective hydroformylation of a large range of alkenes and alkynes, including sensitive starting materials. Its utility is demonstrated in the synthesis of antiobesity drug Rimonabant and anti-HIV agent PNU-32945. In a broader context, the new mechanistic understanding enables the development of other carbonylation reactions of high importance to chemical industry.
- Zhang, Yang,Torker, Sebastian,Sigrist, Michel,Bregovi?, Nikola,Dydio, Pawe?
-
supporting information
p. 18251 - 18265
(2020/11/02)
-
- Catalytic isomerization-hydroformylation of olefins by rhodium salicylaldimine pre-catalysts
-
A series of new Schiff-base rhodium(i) water-soluble complexes (C1-C3), were prepared and characterized. These complexes served as catalyst precursors for the hydroformylation of 1-octene and resulted in excellent substrate conversions (>98%) with 100% chemoselectivities to aldehydes, under mild conditions. Notably, good regioselectivities towards branched aldehydes were observed clearly demonstrating the catalysts’ ability in thermodynamically favoured isomerization followed by hydroformylation (n/iso ratio ranging between 0.7-1.2). Interestingly, catalystC1uniquely promoted contra-thermodynamic isomerization of 2-octene to 1-octene with up to 50% conversion. The efficacy of catalystC1was further evaluated in the hydroformylation of longer chain olefins (C10-C12), methyl acrylate, ethyl acrylate and styrene. The catalyst displayed conversions >99% with the long chain substrates and much lower conversions with the acrylates. These water-soluble (pre)catalysts were recycled up to three times with no significant loss in catalytic activity and selectivity. Mercury poisoning tests were conducted and the experiments revealed that the conversion of the substrates into aldehydes was due to molecular active catalysts and not as a result of colloidal particles that could have formedin situthrough the decomposition of the catalyst precursor. Finally, the molecular catalyst responsible for activity was established using preliminary computational calculations.
- Sekoto, Pamela N.,Magengenene, Tseliso M.,Matsinha, Leah C.,Tia, Richard,Darkwa, James,Makhubela, Banothile C. E.
-
p. 8751 - 8762
(2020/06/08)
-
- Hydroformylation of higher olefins in aqueous biphasic medium using rhodium-sulfoxantphos catalyst: Activity and selectivity study
-
Hydroformylation of higher olefins such as 1-hexene, 1-octene, 1-decene and 1-dodecene has been studied in an aqueous biphasic medium using water-soluble Rh-sulfoxantphos complex catalyst. The effect of temperature, presence of various co-solvents and concentration of co-solvent on the reaction rate and chemo and regioselectivity was investigated. N-Methyl pyrrolidone (NMP) was found to be the best co-solvent, which enhances the rate dramatically (4-96 fold) as compared to the reactions in aqueous-organic biphasic medium for hydroformylation of higher olefins. Catalyst recycle study was performed to check the leaching of metal in organic phase.
- Pagar, Nitin S.,Deshpande, Raj M.
-
p. 2061 - 2066
(2020/09/01)
-
- Catalytic Selective Oxidation of Primary and Secondary Alcohols Using Nonheme [Iron(III)(Pyridine-Containing Ligand)] Complexes
-
The selective oxidation of different primary and secondary alcohols to carbonyl compounds by hydrogen peroxide was found to be catalyzed in conversion ranging from good to excellent by an iron(III) complex of a pyridine-containing macrocyclic ligand (Pc-L), without the need of any additive. The choice of the counteranion (Cl, Br, OTf) appeared to be of fundamental importance and the best results in terms of selectivity (up to 99 %) and conversion (up to 98 %) were obtained using the well-characterized [Fe(III)(Br)2(Pc-L)]Br complex, 4c. Magnetic moments in solid-state, also confirmed in solution ([D6]DMSO) by Evans NMR method, were calculated and point out to an iron metal center in the high spin state of 5/2. The crystal structure shows that the iron(III) center is coordinated by the four nitrogen atoms of the macrocycle and two bromide anions to form a distorted octahedral coordination environment. The catalytic oxidation of benzyl alcohol in acetonitrile was found occurring with better conversions and selectivities than in other solvents. The reaction proved to be quite general, tolerating aromatic and aliphatic alcohols, although very low yields were obtained for terminal aliphatic alcohols. Preliminary mechanistic studies are in agreement with a catalytic cycle promoted by a high-spin iron complex.
- Caselli, Alessandro,Gallo, Emma,Panza, Nicola,Rizzato, Silvia,Tseberlidis, Giorgio,di Biase, Armando
-
supporting information
p. 6635 - 6644
(2020/10/30)
-
- Two-way homologation of aliphatic aldehydes: Both one-carbon shortening and lengthening via the same intermediate
-
Aliphatic aldehydes can be homologated to both one-carbon shorter and one-carbon longer homologous carbonyl compounds through the 2–4 steps of reactions via the same intermediates, β,γ-unsaturated α-nitrosulfones, prepared from the proline-catalyzed sequential reactions of several aliphatic aldehydes with phenylsulfonylnitromethane. While the oxidative cleavage of the key intermediates gave one-carbon less homologous carbonyl compounds, the reduction of the same key intermediates followed by an oxidation produced one-carbon more homologous carbonyl compounds.
- Yoo, Jae Won,Seo, Youngran,Park, Jong Beom,Kim, Young Gyu
-
-
- Homogeneous hydroformylation of long chain alkenes catalyzed by water soluble phosphine rhodium complex in CH3OH and efficient catalyst cycling
-
The hydroformylation of long chain alkenes catalyzed by a water soluble Rh/TPPTS complex (TPPTS: sodium salt of sulfonated triphenylphosphine) in methanol was investigated. The mixture of rhodium precursor HRh(CO)(TPPTS)3, ligand TPPTS, methanol and a long chain alkene becomes a single phase under reaction conditions, which make the hydroformylation reaction proceed homogeneously. Both the conversion of long chain alkene and the selectivity to aldehydes (including the aldehydes forming methylacetals) could reach up to 97.8% and 97.6%, respectively, with 3323 h?1 of TOF (TOF: turnover frequency is defined as the moles of converted alkene per mole of Rh per hour). After the solvent methanol was removed under the reaction temperature, two phases were formed automatically. The colourless product phase could be efficiently separated from the precipitate rhodium catalyst phase by centrifuge. The catalyst was reused for five times without obvious loss of rhodium and the catalytic activity. The rhodium leaching in product mixture was less than 0.03% of the total rhodium.
- Liu, Yan-li,Zhao, Jian-gui,Zhao, Yuan-jiang,Liu, Hui-Min,Fu, Hai-yan,Zheng, Xue-li,Yuan, Mao-lin,Li, Rui-xiang,Chen, Hua
-
p. 7382 - 7387
(2019/03/19)
-
- Encapsulated liquid nano-droplets for efficient and selective biphasic hydroformylation of long-chain alkenes
-
Aqueous nano-droplets of homogeneous Rh-TPPTS catalyst encapsulated within the cavity of hollow silica nanospheres were fabricated for biphasic hydroformylation of long-chain alkenes, which showed significant reaction rate enhancement effects and improved aldehyde selectivity.
- Zhang, Xiaoli,Wei, Juan,Zhang, Xiaoming
-
supporting information
p. 14134 - 14138
(2019/09/18)
-
- Metal-free mechanochemical oxidations in Ertalyte jars
-
The authors acknowledge Form-Tech Scientific for the loan of the FTS-1000 Shaker Mill apparatus (Form-Tech Scientific, Canada, https://formtechscientific.com/). Authors are grateful to MIUR (Italy, PRIN project: multifunctional polymer composites based on grown materials). A. P. is grateful to MIUR for “Finanziamento delle Attività Base di Ricerca (FABR 2017)“.
- Porcheddu, Andrea,Delogu, Francesco,De Luca, Lidia,Fattuoni, Claudia,Colacino, Evelina
-
supporting information
p. 1786 - 1794
(2019/08/07)
-
- Copper(I)- and Mesoionic-Hydroxyamide-Catalyzed Chemoselective Aerobic Oxidation of Primary Benzylic Alcohols
-
A new aerobic oxidation system consisting of Cu(I)I, 2,2'-bipyridine, N -methyl imidazole, and a mesoionic hydroxyamide was developed, with which selective oxidation of a broad range of benzylic alcohols was achieved.
- Matsukawa, Yuta,Hirashita, Tsunehisa
-
p. 315 - 318
(2019/02/12)
-
- A Synthetic Polyester from Plant Oil Feedstock by Functionalizing Polymerization
-
Catalytic functionalization/polymerization of castor oil-derived undecenol yields an aliphatic polyester in a single step under mild conditions. The key to selective formation of linear high melting polyester is highly active carbonylation catalysts that at the same time do not undergo strong isomerization.
- Liu, Ye,Mecking, Stefan
-
supporting information
p. 3346 - 3350
(2019/01/04)
-
- Tris(pyrazolyl)borate Cobalt-Catalyzed Hydrogenation of C=O, C=C, and C=N Bonds: An Assistant Role of a Lewis Base
-
The combination of tris(pyrazolyl)borate cobalt complexes and Lewis base is developed as an efficient catalyst precursor in the homogeneous hydrogenation. A broad substrate scope including carbonyls, alkenes, enamines, and imines is reduced with 60 atm of H2 at 60 °C. Mechanistic studies support the hydrogenation operates through a frustrated Lewis pair (FLP)-like reduction process. These results highlight the development of novel non-noble metal catalytic processes, when combined with the diverse small molecule activation chemistry associated with FLPs.
- Lin, Yang,Zhu, De-Ping,Du, Yi-Ran,Zhang, Rui,Zhang, Suo-Jiang,Xu, Bao-Hua
-
supporting information
p. 2693 - 2698
(2019/04/25)
-
- Normal Alpha Olefin Synthesis Using Dehydroformylation or Dehydroxymethylation
-
The present invention discloses processes for producing normal alpha olefins, such as 1-hexene, 1-octene, 1-decene, and 1-dodecene in a multistep synthesis scheme from another normal alpha olefin. Also disclosed are reactions for converting aldehydes, primary alcohols, and terminal vicinal diols into normal alpha olefins.
- -
-
Paragraph 0139; 0142; 0143; 0149; 0150
(2019/09/06)
-
- Integration of phosphine ligands and ionic liquids both in structure and properties-a new strategy for separation, recovery, and recycling of homogeneous catalyst
-
The major limitation of classic biphasic ionic liquid (IL) catalysis is the heavy use of solvent ILs, which not only violates green chemistry principles but also even worsens catalytic efficiency. So it has always been a challenge finding ways to use ILs more efficiently, economically, and greenly to construct highly effective and long term stable IL catalytic systems. In this work, we synthesized a class of room temperature phosphine-functionalized polyether guanidinium ionic liquids (RTP-PolyGILs) by a convenient ion exchange reaction of polyether guanidinium ionic liquids (PolyGILs) with phosphine-sulfonate ligands based on the concept of the integration of both the phosphine ligand and IL. The resulting RTP-PolyGILs existed as liquids at room temperature and possessed dual functions of both the phosphine ligand and solvent IL; therefore they could both form catalysts by complexing with transition metals and act as catalyst carriers, thus achieving the integration of phosphine ligands with ILs both in structure and properties. Based on the unique properties of these multi-functional integrated RTP-PolyGILs, we constructed a highly effective homogeneous catalysis-biphasic separation (HCBS) system for Rh-catalyzed hydroformylation of higher olefins using only a catalytic amount of RTP-PolyGILs (equivalent to 0.025-0.4 mol% of 1-alkenes). Our HCBS system could be flexibly regulated with regard to catalytic performance (activity and linear selectivity) by changing the structure or type of the sulfonated ligand anion on RTP-PolyGILs. Specifically, it presented a TOF value of 3000-26000 h-1 and a linear selectivity of 68%-98% (corresponding to the l/b ratio of 2.2-37.5) with a total turnover number (TTON) of 11000-45000 and an extremely low Rh leaching of only 0.02-0.4 ppm. Therefore, the HCBS system can effectively combine the advantages of both homogeneous (high activity and good selectivity) and biphasic catalysis (easy catalyst separation). We additionally extended the application of the HCBS system to the hydrogenation of olefins to demonstrate the universality of the RTP-PolyGILs in catalytic reactions.
- Jin, Xin,Feng, Jianying,Song, Hongbing,Yao, Jiajun,Ma, Qingqing,Zhang, Mei,Yu, Cong,Li, Shumei,Yu, Shitao
-
p. 3583 - 3596
(2019/07/10)
-
- Oxidative Cleavage of Long-Chain Terminal Alkenes to Carboxylic Acids
-
Oxidation of aliphatic terminal alkenes having more than 30 carbon atoms to carboxylic acids is presented. Such long carboxylic acids are useful as waxes, lubricants, plasticizers, etc. The oxidation was conducted under solvent-free conditions or with small amounts of diluents (heptane, methylcyclohexane, and tert-butylbenzene). Hydrogen peroxide was used as the oxidant, and tungstic acid was used as the catalyst. Halogen-free quaternary ammonium salts were used as phase-transfer catalysts, and the importance of the elimination of halide ions is discussed. Purification of the crude oxidized product and tungsten removal are also presented. The products have a maximum acid number of 75 mg of KOH/g, a saponification number of 100 mg of KOH/g, and tungsten content below 400 ppm.
- Pyszny, Dariusz,Piotrowski, Tomasz,Orlińska, Beata
-
-
- Oxidative Cleavage of Long-Chain Terminal Alkenes to Carboxylic Acids
-
Oxidation of aliphatic terminal alkenes having more than 30 carbon atoms to carboxylic acids is presented. Such long carboxylic acids are useful as waxes, lubricants, plasticizers, etc. The oxidation was conducted under solvent-free conditions or with small amounts of diluents (heptane, methylcyclohexane, and tert-butylbenzene). Hydrogen peroxide was used as the oxidant, and tungstic acid was used as the catalyst. Halogen-free quaternary ammonium salts were used as phase-transfer catalysts, and the importance of the elimination of halide ions is discussed. Purification of the crude oxidized product and tungsten removal are also presented. The products have a maximum acid number of 75 mg of KOH/g, a saponification number of 100 mg of KOH/g, and tungsten content below 400 ppm.
- Pyszny, Dariusz,Piotrowski, Tomasz,Orlińska, Beata
-
p. 309 - 319
(2019/03/21)
-
- Efficient Vanadium-Catalyzed Aerobic C?C Bond Oxidative Cleavage of Vicinal Diols
-
The aerobic oxidative C?C bond cleavage of vicinal diols catalyzed by vanadium amino triphenolates is described. Our results show that C?C bond cleavage can be performed in different solvents, under an air or oxygen atmosphere, with a large variety of glycols (cyclic or linear, with aromatic or aliphatic substituents) affording the corresponding carbonyl derivatives with high chemoselectivity. Reactions can be performed with as little as 10 ppm of catalyst reaching TON up to 81,000 and TOFs of up to 4150 h?1. A reaction mechanism, rationalized by density functional theory calculations, is also proposed. (Figure presented.).
- Amadio, Emanuele,González-Fabra, Joan,Carraro, Davide,Denis, William,Gjoka, Blerina,Zonta, Cristiano,Bartik, Kristin,Cavani, Fabrizio,Solmi, Stefania,Bo, Carles,Licini, Giulia
-
supporting information
p. 3286 - 3296
(2018/05/30)
-
- A kind of [...] functionalized polyether pyridine salt ion liquid and its olefin hydroformylation reaction in the application of the
-
The present invention relates to a phosphine-functionalized polyether pyridinium salt ionic liquid and a method for biphasic hydroformaylation of olefins based on the phosphine-functionalized polyether pyridinium salt ionic liquid. A biphasic catalytic system is used in the method, wherein the catalytic system consists of a phosphine-functionalized polyether pyridinium salt ionic liquid, a rhodium catalyst, a reaction substrate, olefins, and a reaction product, aldehydes; liquid/liquid biphasic hydroformylation of olefins is performed at a certain reaction temperature and syngas pressure; the phosphine-functionalized polyether pyridinium salt ionic liquid acts both as a phosphine ligand and as a rhodium catalyst carrier; there is no need to add any other ionic liquid to the system; and separation and recycling of the rhodium catalyst are realized by liquid/liquid biphasic separation after the reaction. The catalytic system provided by the present invention is high in catalytic activity. The rhodium catalyst is capable of being recycled for many times with no obvious decrease in catalytic activity or selectivity.
- -
-
Paragraph 0026; 0027; 0033; 0053; 0055
(2018/05/24)
-
- Heterogeneous hydroformylation of long-chain alkenes in IL-in-oil Pickering emulsion
-
An efficient heterogeneous catalytic system for hydroformylation of long-chain alkenes is highly desirable for both academy and industry. In this study, an IL-in-oil Pickering emulsion system was employed for heterogeneous hydroformylation of 1-dodecene with Rh-sulfoxantphos as the catalyst and surface modified dendritic mesoporous silica nanospheres (DMSN) as the stabilizer. The IL-in-oil Pickering emulsion system outperformed IL-oil biphase, water-in-oil Pickering emulsion and IL-oil micelle system under similar reaction conditions to afford n/b ratio of 98:2, chemoselectivity of 94% and TOF of 413 h-1, among the highest ever reported for IL-oil biphase hydroformylation of long-chain alkenes. The high efficiency of IL-in-oil Pickering emulsion was primarily attributed to the increased interface area and unique properties of ILs. Studies also revealed that solid stabilizers with large and open pore channels could greatly increase the reaction rate of Pickering emulsion systems by accelerating the diffusion rate. The recyclable IL-in-oil Pickering emulsion is promising not only for hydroformylation of long-chain alkenes but also for catalytic reactions with immiscible liquids.
- Tao, Lin,Zhong, Mingmei,Chen, Jian,Jayakumar, Sanjeevi,Liu, Lina,Li, He,Yang, Qihua
-
p. 188 - 196
(2018/01/12)
-
- Nonaqueous Biphasic Hydroformylation of Long Chain Alkenes Catalyzed by Water Soluble Phosphine Rhodium Catalyst with Polyethylene Glycol Instead of Water
-
Abstract: The application of polyethylene glycol (donated as PEG), as an environmentally benign solvent instead of water, in rhodium catalyzed hydroformylation of long chain alkenes by using water soluble phosphine BISBIS or TPPTS (TPPTS: sodium salt of sulfonated triphenylphosphine, BISBIS: sodium salt of sulfonated 2,2′-bis(diphenylphosphinomethyl)-1,1′-biphenyl) is herein reported. The conversion of long chain alkenes in PEG-200 could reach above 95.0% after a short reaction time (15?min). In addition, an efficient phase separation and recycling of PEG-200 and catalyst were achieved. The leaching of rhodium into product phase detected by ICP-AES was less than 0.06?wt% of the initial amount. Graphical Abstract: [Figure not available: see fulltext.].
- Zhao, Yuanjiang,Liu, Yanli,Wei, Jianzhang,Fu, Haiyan,Zheng, Xueli,Yuan, Maolin,Li, Ruixiang,Chen, Hua
-
p. 438 - 442
(2017/12/04)
-
- Iron Catalyzed Hydroformylation of Alkenes under Mild Conditions: Evidence of an Fe(II) Catalyzed Process
-
Earth abundant, first row transition metals offer a cheap and sustainable alternative to the rare and precious metals. However, utilization of first row metals in catalysis requires harsh reaction conditions, suffers from limited activity, and fails to tolerate functional groups. Reported here is a highly efficient iron catalyzed hydroformylation of alkenes under mild conditions. This protocol operates at 10-30 bar syngas pressure below 100 °C, utilizes readily available ligands, and applies to an array of olefins. Thus, the iron precursor [HFe(CO)4]-[Ph3PNPPh3]+ (1) in the presence of triphenyl phosphine catalyzes the hydroformylation of 1-hexene (S2), 1-octene (S1), 1-decene (S3), 1-dodecene (S4), 1-octadecene (S5), trimethoxy(vinyl)silane (S6), trimethyl(vinyl)silane (S7), cardanol (S8), 2,3-dihydrofuran (S9), allyl malonic acid (S10), styrene (S11), 4-methylstyrene (S12), 4-iBu-styrene (S13), 4-tBu-styrene (S14), 4-methoxy styrene (S15), 4-acetoxy styrene (S16), 4-bromo styrene (S17), 4-chloro styrene (S18), 4-vinylbenzonitrile (S19), 4-vinylbenzoic acid (S20), and allyl benzene (S21) to corresponding aldehydes in good to excellent yields. Both electron donating and electron withdrawing substituents could be tolerated and excellent conversions were obtained for S11-S20. Remarkably, the addition of 1 mol % acetic acid promotes the reaction to completion within 16-24 h. Detailed mechanistic investigations revealed in situ formation of an iron-dihydride complex [H2Fe(CO)2(PPh3)2] (A) as an active catalytic species. This finding was further supported by cyclic voltammetry investigations and intermediacy of an Fe(0)-Fe(II) species was established. Combined experimental and computational investigations support the existence of an iron-dihydride as the catalyst resting state, which then follows a Fe(II) based catalytic cycle to produce aldehyde.
- Pandey, Swechchha,Raj, K. Vipin,Shinde, Dinesh R.,Vanka, Kumar,Kashyap, Varchaswal,Kurungot, Sreekumar,Vinod,Chikkali, Samir H.
-
supporting information
p. 4430 - 4439
(2018/04/05)
-
- Multiphasic aqueous hydroformylation of 1-alkenes with micelle-like polymer particles as phase transfer agents
-
Micelle-like polymer particles have been applied in aqueous multiphasic hydroformylation reactions of long chain alkenes. These colloids act as phase transfer agents for the nonpolar substrates and as carriers for the catalyst bearing sulfonated ligands by electrostatic attraction. The catalyst performance and the phase separation were optimized with special focus on the conversion, selectivity and catalyst recovery, as those are key points in multiphasic systems to achieve a feasible industrial process. The effect on the catalyst performance of the number of sulfonate groups and electron withdrawing trifluoromethyl groups in the ligand has been studied. The approach was successfully demonstrated for 1-alkenes from 1-hexene to 1-dodecene. For 1-octene, a TOF of more than 3000 h?1 could be achieved at a substrate to catalyst ratio of 80?000, while keeping the rhodium and phosphorous leaching below 1 ppm. In repetitive batch experiments the catalyst was recycled four times, yielding an accumulated TON of more than 100?000 for 1-octene.
- Bibouche, Bachir,Peral, Daniel,Stehl, Dmitrij,S?derholm, Viktor,Schom?cker, Reinhard,Von Klitzing, Regine,Vogt, Dieter
-
p. 23332 - 23338
(2018/07/10)
-
- Based on [...] functionalized polyether alkyl guanidine salt ion liquid of the two-phase hydroformylation of olefins method
-
The present invention relates to a method for biphasic hydroformaylation of olefins based on a phosphine-functionalized polyether alkyl guanidine salt ionic liquid. A biphasic catalytic system is used in the method, wherein the catalytic system consists of the phosphine-functionalized polyether alkyl guanidine salt ionic liquid, a rhodium catalyst, a reaction substrate - olefins and a reaction product - aldehydes; liquid/liquid biphasic hydroformylation of olefins is performed at a certain reaction temperature and syngas pressure; the phosphine-functionalized polyether alkyl guanidine salt ionic liquid acts both as a phosphine ligand and as a rhodium catalyst carrier; there is no need to add any other ionic liquid to the system; separation and recycling of the rhodium catalyst are realized by liquid/liquid biphasic separation after the reaction; the rhodium catalyst is capable of being recycled for multiple times with no obvious decrease in catalytic activity or selectivity; the TOF value of the system reaches 240-2700h-1; and the highest catalytic cycle cumulative TON value reaches 47138.
- -
-
Paragraph 0042; 0043; 0044
(2018/09/26)
-
- A kind of [...] functionalized polyether quaternary ammonium salt ion liquid and its olefin hydroformylation reaction in the application of the (by machine translation)
-
The invention relates to a phosphine-functionalized polyether quaternary ammonium salt ionic liquid, and a method of two-phase hydroformylation of olefins on the basis of the phosphine-functionalized polyether quaternary ammonium salt ionic liquid. In the invention, a two-phase catalysis system is employed, wherein the catalysis system is composed of the phosphine-functionalized polyether quaternary ammonium salt ionic liquid, a rhodium catalyst and a reaction substrate olefin and a reaction product aldehyde. A liquid-liquid two-phase hydroformylation reaction is carried out at a certain reaction temperature and under a synthesis gas pressure, wherein the phosphine-functionalized polyether quaternary ammonium salt ionic liquid is not only a phosphine ligand but also a carrier of the rhodium catalyst, so that the system is free of addition of other ionic liquids. When the reaction is finished, the rhodium catalyst is separated and recycled through simple liquid-liquid two-phase separation. The catalytic system is high in catalytic activity. The rhodium catalyst can be used repeatedly for several times without significant reduction of catalytic activity and selectivity.
- -
-
Paragraph 0053; 0066-0068
(2018/05/24)
-
- Nitrosotetrazolium-Catalyzed Aerobic Oxidation of Alcohols to the Corresponding Carbonyl Compounds
-
A mesoionic-nitrosotetrazolium-catalyzed aerobic oxidation of alcohols is reported. In the presence of catalytic amounts of 5-nitroso-1,3-diphenyltetrazolium tetrafluoroborate (5 mol-%) and nitric acid (20 mol-%), a wide range of alcohols are oxidized to the corresponding aldehydes and ketones in yields of 53–100 % at room temperature under ambient air or oxygen conditions. This oxidation shows a strong preference for secondary alcohols over primary alcohols; sterically hindered alcohols are also smoothly oxidized. A mechanism involving a nitroso/NOx catalytic cycle is proposed.
- Matsukawa, Yuta,Hirashita, Tsunehisa,Araki, Shuki
-
p. 1359 - 1363
(2018/04/02)
-
- The sustainable synthesis of peptidomimetics via chemoenzymatic tandem oxidation-Ugi reaction
-
A simply and green synthetic protocol based on the selective laccase-oxidation of alcohol to a corresponding aldehyde and a following Ugi reaction in a micellar system made of SDS was developed and is reported herein. Special emphasis was placed on the metal-free chemoenzymatic tandem reaction based on alcohol oxidation strategies using molecular oxygen from air, followed by an Ugi reaction. The reaction was carried out without the use of a transition metal or organic solvents as a reaction medium. The presented protocol offers an efficient and environmentally friendly procedure.
- Madej, Arleta,Koszelewski, Dominik,Paprocki, Daniel,Brodzka, Anna,Ostaszewski, Ryszard
-
p. 28405 - 28413
(2018/08/29)
-
- Revisiting Sodium Hypochlorite Pentahydrate (NaOCl·5H 2 O) for the Oxidation of Alcohols in Acetonitrile without Nitroxyl Radicals
-
Sodium hypochlorite pentahydrate (NaOCl·5H 2 O) is capable of oxidizing alcohols in acetonitrile at 20 °C without the use of catalysts. The oxidation is selective to allylic, benzylic, and secondary alcohols. Aliphatic primary alcohols are not oxidized.
- Hirashita, Tsunehisa,Sugihara, Yuto,Ishikawa, Shota,Naito, Yohei,Matsukawa, Yuta,Araki, Shuki
-
p. 2404 - 2407
(2018/11/23)
-
- Normal Alpha Olefin Synthesis Using Metathesis and Dehydroformylation
-
The present invention discloses processes for producing normal alpha olefins, such as 1-hexene, 1-octene, and 1-decene, in a multistep synthesis scheme. Generally, a first normal alpha olefin is subjected to an olefin metathesis step to form a linear internal olefin, which is then subjected to an isomerization-hydroformylation step to form a linear aldehyde, which is then subjected to a dehydroformylation step to form a second normal alpha olefin.
- -
-
Paragraph 0092; 0095; 0096; 0099; 0102; 0103
(2018/05/24)
-
- Thermal, Catalytic Conversion of Alkanes to Linear Aldehydes and Linear Amines
-
Alkanes, the main constituents of petroleum, are attractive feedstocks for producing value-added chemicals. Linear aldehydes and amines are two of the most important building blocks in the chemical industry. To date, there have been no effective methods for directly converting n-alkanes to linear aldehydes and linear amines. Here, we report a molecular dual-catalyst system for production of linear aldehydes via regioselective carbonylation of n-alkanes. The system is comprised of a pincer iridium catalyst for transfer-dehydrogenation of the alkane using t-butylethylene or ethylene as a hydrogen acceptor working sequentially with a rhodium catalyst for olefin isomerization-hydroformylation with syngas. The system exhibits high regioselectivity for linear aldehydes and gives high catalytic turnover numbers when using ethylene as the acceptor. In addition, the direct conversion of light alkanes, n-pentane and n-hexane, to siloxy-terminated alkyl aldehydes through a sequence of Ir/Fe-catalyzed alkane silylation and Ir/Rh-catalyzed alkane carbonylation, is described. Finally, the Ir/Rh dual-catalyst strategy has been successfully applied to regioselective alkane aminomethylation to form linear alkyl amines.
- Tang, Xinxin,Jia, Xiangqing,Huang, Zheng
-
supporting information
p. 4157 - 4163
(2018/03/29)
-
- Selective ligand-free cobalt-catalysed reduction of esters to aldehydes or alcohols
-
Cobalt(ii) salts combined with NaBHEt3 and eventually a base catalyse efficiently and selectively the reduction of esters to aldehydes or alcohols through hydrosilylation by using phenylsilane. Catalyst characterisation by XRD, XPS, TEM and STEM analyses indicates the materials were partially crystalline with the presence of cobalt nanoparticles. Control experiments suggested low valent Co(0) was the active catalytic species involved.
- Rysak, Vincent,Descamps-Mandine, Armel,Simon, Pardis,Blanchard, Florent,Burylo, Laurence,Trentesaux, Martine,Vandewalle, Maxence,Collière, Vincent,Agbossou-Niedercorn, Francine,Michon, Christophe
-
p. 3504 - 3512
(2018/07/29)
-
- Water-soluble phosphane-substituted cyclodextrin as an effective bifunctional additive in hydroformylation of higher olefins
-
In cyclodextrin (CD)-mediated aqueous biphasic catalysis, favoring contacts between the CD ("host"), the organic substrate ("guest") and the water-soluble catalyst is crucial for the reaction to proceed efficiently at the aqueous/organic interface. Grafting the catalyst onto the CD backbone thus appears as an attractive approach to favor the molecular recognition of the substrate and its subsequent catalytic conversion into products. In this context, a new water-soluble β-CD-based phosphane was synthesized and characterized by NMR, tensiometric and ITC measurements. The β-CD-based phosphane consisted of a 3,3′-disulfonatodiphenyl phosphane connected to the primary face of β-CD by a dimethyleneamino spacer. Intra- and intermolecular inclusion processes of one of the two sulfophenyl groups into the β-CD cavity were identified in water. However, the association constant (Ka) related to the β-CD/sulfophenyl group couple was low. Accordingly, the inclusion process was easily displaced upon coordination to rhodium complexes. The efficacy of the resulting Rh-complex coordinated by β-CD-based phosphanes was assessed in Rh-catalyzed hydroformylation of higher olefins. The catalytic system proved to be far more successful and efficient than a system consisting of supramolecularly interacting phosphanes and CDs. The catalytic activity was up to 30-fold higher while the chemo- and regioselectivities remain rather unchanged.
- Leblond,Potier,Menuel,Bricout,Machut-Binkowski,Landy,Tilloy,Monflier,Hapiot
-
p. 3823 - 3830
(2017/09/07)
-
- A kind of [...] functionalized polyether quaternary phosphonium ionic liquid and its olefin hydroformylation reaction in the application of the (by machine translation)
-
The invention relates to a functionalized polyether quaternary phosphonium salt [...] ionic liquid, and a functionalized polyether quaternary phosphonium salt based on [...] ionic liquid two-phase hydroformylation of olefins of the method, the method uses a two-phase catalytic system, the catalytic system is composed of [...] functionalized polyether quaternary phosphonium ion liquid, rhodium catalyst and reaction substrate olefin and reaction aldehyde composition, in a certain reaction temperature and the synthesis gas is conducted under a pressure liquid/liquid two-phase hydroformylation reaction, [...] functionalized polyether quaternary phosphonium ionic liquid is phosphine, at the same time also acts as the rhodium catalyst carrier, system do not need in in addition introducing other ionic liquid, after the reaction through a simple liquid/liquid two-phase separation [...] separation and recycle of the catalyst, the catalytic system has higher catalytic activity, rhodium catalyst can be circulated many times, catalytic activity and selectivity without significant decrease. (by machine translation)
- -
-
Paragraph 0049-0051
(2017/11/16)
-
- A TEMPO-like nitroxide combined with an alkyl-substituted pyridine: An efficient catalytic system for the selective oxidation of alcohols with iodine
-
An efficient method for the oxidation of alcohols to aldehydes or ketones in a two-phase CH2Cl2/NaHCO3 (aq.) system, using iodine and catalytic amounts of 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxyl and 2,4,6-trimethylpyridine, was developed. The performance of the method was demonstrated by the selective oxidation of 37 variously substituted alcohols in ≥90% yield, including the gram-scale synthesis of the important chemical 2,5-diformylfuran from biomass-derived 5-hydroxylmethylfurfural.
- Kashparova, Vera P.,Klushin, Victor A.,Zhukova, Irina Yu.,Kashparov, Igor S.,Chernysheva, Daria V.,Il'chibaeva, Irina B.,Smirnova, Nina V.,Kagan, Efim Sh.,Chernyshev, Victor M.
-
supporting information
p. 3517 - 3521
(2017/10/05)
-
- Rhodium-Complex-Catalyzed Hydroformylation of Olefins with CO2and Hydrosilane
-
A rhodium-catalyzed one-pot hydroformylation of olefins with CO2, hydrosilane, and H2has been developed that affords the aldehydes in good chemoselectivities at low catalyst loading. Mechanistic studies indicate that the transformation is likely to proceed through a tandem sequence of poly(methylhydrosiloxane) (PMHS) mediated CO2reduction to CO and a conventional rhodium-catalyzed hydroformylation with CO/H2. The hydrosilylane-mediated reduction of CO2in preference to aldehydes was found to be crucial for the selective formation of aldehydes under the reaction conditions.
- Ren, Xinyi,Zheng, Zhiyao,Zhang, Lei,Wang, Zheng,Xia, Chungu,Ding, Kuiling
-
supporting information
p. 310 - 313
(2016/12/30)
-
- Enzyme Activity by Design: An Artificial Rhodium Hydroformylase for Linear Aldehydes
-
Artificial metalloenzymes (ArMs) are hybrid catalysts that offer a unique opportunity to combine the superior performance of natural protein structures with the unnatural reactivity of transition-metal catalytic centers. Therefore, they provide the prospect of highly selective and active catalytic chemical conversions for which natural enzymes are unavailable. Herein, we show how by rationally combining robust site-specific phosphine bioconjugation methods and a lipid-binding protein (SCP-2L), an artificial rhodium hydroformylase was developed that displays remarkable activities and selectivities for the biphasic production of long-chain linear aldehydes under benign aqueous conditions. Overall, this study demonstrates that judiciously chosen protein-binding scaffolds can be adapted to obtain metalloenzymes that provide the reactivity of the introduced metal center combined with specifically intended product selectivity.
- Jarvis, Amanda G.,Obrecht, Lorenz,Deuss, Peter J.,Laan, Wouter,Gibson, Emma K.,Wells, Peter P.,Kamer, Paul C. J.
-
supporting information
p. 13596 - 13600
(2017/09/25)
-
- A kind of [...] functionalized polyether piperidine salt ion liquid and its olefin hydroformylation reaction in the application of the
-
The present invention relates to a phosphine-functionalized polyether piperidine salt ionic liquid and a method for biphasic hydroformaylation of olefins based on the phosphine-functionalized polyether piperidine salt ionic liquid. The method uses a biphasic catalytic system, wherein the catalytic system consists of a phosphine-functionalized polyether piperidine salt ionic liquid, a rhodium catalyst, the reaction substrate, olefins and the reaction product, aldehydes; liquid/liquid biphasic hydroformylation of olefins is performed at a certain reaction temperature and syngas pressure; the phosphine-functionalized polyether piperidine salt ionic liquid acts both as a phosphine ligand and as a rhodium catalyst carrier; there is no need to add any other ionic liquid to the system; and separation and recycling of the rhodium catalyst are realized by liquid/liquid biphasic separation after the reaction. The catalytic system provided by the present invention is high in catalytic activity. The rhodium catalyst is capable of being recycled for many times with no obvious decrease in catalytic activity and selectivity.
- -
-
Paragraph 0025-0027; 0058-0060
(2017/11/16)
-
- Substituent Effects on the pH Sensitivity of Acetals and Ketals and Their Correlation with Encapsulation Stability in Polymeric Nanogels
-
The effect of structural variations in acetal- and ketal-based linkers upon their degradation kinetics is studied through the design, synthesis, and study of six series of molecules, comprising a total of 18 different molecules. Through this systematic study, we show that the structural fine-tuning of the linkers allows access to variations in kinetics of degradation of more than 6 orders of magnitude. Hammett correlations show that the ρ value for the hydrolysis of benzylidene acetals is about ?4.06, which is comparable to an SN1-like process. This shows that there is a strong, developing positive charge at the benzylic position in the transition state during the degradation of acetals. This positively charged transition state is consistent with the relative degradation rates of acetals vs ketals (correlated to stabilities of 1°, 2°, and 3° carboxonium ion type intermediates) and the observed effect of proximal electron-withdrawing groups upon the degradation rates. Following this, we studied whether the degradation kinetics study correlates with pH-sensitive variations in the host-guest characteristics of polymeric nanogels that contains these acetal or ketal moieties as cross-linking functionalities. Indeed, the trends observed in the small molecule degradation have clear correlations with the encapsulation stability of guest molecules within these polymeric nanogels. The implications of this fundamental study extend to a broad range of applications, well beyond the polymeric nanogel examples studied here.
- Liu, Bin,Thayumanavan
-
p. 2306 - 2317
(2017/02/23)
-
- Method for high-selectivity preparation of normal aldehyde through olefin two-phase hydroformylation on basis of polyether pyridinium ionic liquid
-
The invention relates to a method for high-selectivity preparation of normal aldehyde through olefin two-phase hydroformylation on the basis of a polyether pyridinium ionic liquid. According to the method, a two-phase catalytic system is adopted, the catalytic system comprises a polyether pyridinium ionic liquid PPYILs with room temperature liquid-solid phase change characteristics, a rhodium catalyst, diphosphine ligands, a reaction substrate olefin and a reaction product aldehyde, a liquid/liquid two-phase hydroformylation reaction is performed at certain reaction temperature and under certain synthesis gas pressure, and the rhodium catalyst is recovered and cycled through simple two-phase separation after the reaction ends. The catalytic system has high catalytic activity, high selectivity, ultralong service life and very low rhodium catalyst loss amount, wherein the TOF value reaches 160-220 h; the area selectivity of normal aldehyde reaches 96%-98%; the catalytic cycle accumulated TON value is approximately 40,000; the rhodium catalyst loss amount is only 0.06%-0.2%.
- -
-
Paragraph 0025-0027; 0070-0072;0073-0075
(2017/03/08)
-
- Method of preparing normal aldehyde in highly selective manner through olefin two-phase hydroformylation on basis of polyether piperidine salt ion liquid
-
The invention relates to a method of preparing normal aldehyde in a highly selective manner through olefin two-phase hydroformylation on the basis of polyether piperidine salt ion liquid. The method includes: adopting a two-phase catalysis system which is composed of polyether piperidine salt ion liquid with room temperature liquid-solid phase transition characteristics, rhodium catalyst, diphosphine ligand, reaction substrate olefin and reaction product aldehyde; performing liquid/liquid two-phase hydroformylation at certain reaction temperature and synthetic gas pressure; after reaction is finished, recycling and circulating the rhodium catalyst through simple two-phase separation, wherein the rhodium catalyst can be circulated for use for dozens of times without obviously lowering catalytic activity and selectivity. TOF value of the system reaches 300-2400 h, catalytic circulating accumulated TON value reaches higher than 32489 to maximum extent, regioselectivity of the normal aldehyde is up to 96-98%, an rhodium loss is only 0.02-0.10%.
- -
-
Paragraph 0029; 0077-0079
(2017/04/11)
-
- Method for highly selectively preparing normal aldehyde through alkene two-phase hydroformylation based on polyether pyrrolidine salt ion liquid
-
The invention relates to a method for highly selectively preparing normal aldehyde through alkene two-phase hydroformylation based on polyether pyrrolidine salt ion liquid. A two-phase catalytic system is used herein and comprises polyether pyrrolidine salt ion liquid having indoor temperature liquid-solid phase change characteristics, a rhodium catalyst, diphosphine ligand, a reaction substrate alkene and a reaction product aldehyde; liquid/liquid two-phase hydroformylation is carried under certain reaction temperature and synthetic gas pressure, the rhodium catalyst is recycled through simple two-phase separation after reacting, the rhodium catalyst can be recycled tens of times, there is no significant decrease in catalytic activity and selectivity, TOF value of this system reaches 260-2000 h, catalytic circulatory accumulative TON value is up to higher than 34000, regioselectivity of the normal aldehyde is up to 96-98%, and rhodium loss is just 0.05-0.15%.
- -
-
Paragraph 0027; 0074; 0076-0077
(2017/06/02)
-
- Identification and synthesis of the male-produced sex pheromone of the soldier beetle chauliognathus fallax (Coleoptera: Cantharidae)
-
Chauliognathus fallax Germar 1824 (Coleoptera: Cantharidae) occurs in North and South America and Australia. Gas chromatographic (GC) analyses of volatiles released by adults showed the presence of a male specific compound. GC coupled with electroantennographic detection (GC-EAD) showed that this compound is exclusively bioactive on female antennae, suggesting it to be a sex pheromone. GC coupled with mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (GC-FTIR), as well as dimethyl disulfide (DMDS) derivatization and hydrogenation, suggested the target compound to be (Z)-tricos-11-ene. Unambiguous structural proof was achieved by independent synthesis, whereas the biological significance of the compound as a sex pheromone was confirmed by field bioassays.
- Vidal, Diogo M.,Fávaro, Carla F.,Guimar?es, Matheus M.,Zarbin, Paulo H. G.
-
p. 1506 - 1511
(2016/08/10)
-