1117-86-8Relevant articles and documents
Epoxidation of alkenes catalyzed by some molybdenum(0) and molybdenum(IV) complexes
Acharya, Sitaram,Hanna, Tracy A.
, p. 113 - 123 (2016)
Catalytic epoxidations of styrene, cyclohexene, 1-octene, and 3,3-dimethyl-1-butene have been explored utilizing a variety of molybdenum(0) and molybdenum(IV) complexes as precatalysts and tert-butylhydroperoxide (TBHP) as oxidant. The catalytic activities of the complexes MoCl4(CH3CN)2, Mo(CO)3(PTA)3 (PTA = 1,3,5-triaza-7-phosphaadamantane), Mo(CO)3(Mes), and a molybdenum(IV) calix[4]arene salt, [Et3NH][Mo{tBuC4}Cl(CH3CN)] have been investigated. The progress of reactions was monitored with reference to an internal standard by means of 1H NMR spectroscopy. Most of the complexes were found to be effective precatalysts with low catalyst loadings, giving rise to good to excellent conversion of alkenes and yield of the epoxides with the formation of minimal amount of corresponding diol and other side products. The catalytic reactions were found to be most efficient between 100 and 110 °C in minimal solvent or without added solvent.
Rate-determining water-assisted O-O bond cleavage of an Fe III-OOH intermediate in a bio-inspired nonheme iron-catalyzed oxidation
Oloo, Williamson N.,Fielding, Andrew J.,Que, Lawrence
, p. 6438 - 6441 (2013)
Hydrocarbon oxidations by bio-inspired nonheme iron catalysts and H 2O2 have been proposed to involve an FeIII-OOH intermediate that decays via a water-assisted mechanism to form an Fe V(O)(OH) oxidant. Herein we report kinetic evidence for this pathway in the oxidation of 1-octene catalyzed by [FeII(TPA)(NCCH 3)]2+ (1, TPA = tris(2-pyridylmethyl)amine). The (TPA)FeIII(OOH) intermediate 2 can be observed at -40 C and is found to undergo first-order decay, which is accelerated by water. Interestingly, the decay rate of 2 is comparable to that of product formation, indicating that the decay of 2 results in olefin oxidation. Furthermore, the Eyring activation parameters for the decay of 2 and product formation are identical, and both processes are associated with an H2O/D2O KIE of 2.5. Taken together with previous 18O-labeling data, these results point to a water-assisted heterolytic O-O bond cleavage of 2 as the rate-limiting step in olefin oxidation.
Iron-catalyzed olefin cis-dihydroxylation by H2O2: Electrophilic versus nucleophilic mechanisms
Fujita, Megumi,Costas, Miquel,Que Jr., Lawrence
, p. 9912 - 9913 (2003)
Previous studies have classified a series of nonheme iron catalysts for olefin cis-dihydroxylation by H2O2 into two groups. Complex 1, [(TPA)Fe(OTf)2], representative of Class A catalysts, forms a low-spin FeIII-OOH intermediate that gives rise to a high-valent FeV(=O)OH oxidant. The preference of this catalyst for electron-rich olefins demonstrates its electrophilic character. On the other hand, complex 2, [(6-Me3-TPA)Fe(OTf)2], representative of Class B catalysts, prefers instead to oxidize electron-deficient olefins, suggesting an oxidant with nucleophilic character. It is suggested that such a nucleophilic oxidant may be the high-spin FeIII-OOH intermediate derived from 2 or the FeIV(=O)(?OH) species derived therefrom. Copyright
OsO(4) in ionic liquid [Bmim]PF(6): a recyclable and reusable catalyst system for olefin dihydroxylation. remarkable effect of DMAP.
Yao, Qingwei
, p. 2197 - 2199 (2002)
[reaction: see text] The combination of the ionic liquid [bmim]PF(6) and DMAP provides a most simple and practical approach to the immobilization of OsO(4) as catalyst for olefin dihydroxylation. Both the catalyst and the ionic liquid can be repeatedly recycled and reused in the dihydroxylation of a variety of olefins with only a very slight drop in catalyst activity.
Access to enantiopure aromatic epoxides and diols using epoxide hydrolases derived from total biofilter DNA
Kotik, Michael,Stepanek, Vaclav,Grulich, Michal,Kyslik, Pavel,Archelas, Alain
, p. 41 - 48 (2010)
Metagenomic DNA is a rich source of genes encoding novel epoxide hydrolases (EHs). We retrieved two genes encoding functional EHs from total DNA isolated from biofilter-derived biomass, using PCR with EH-specific degenerate primers followed by genome-walking PCR. The degenerate primers were based on two EH-specific consensus sequences: HGWP and GHDWG. The resulting recombinant EHs, Kau2 and Kau8, were expressed in Escherichia coli, and their enantioselectivity and regioselectivity were determined using 13 different epoxide substrates. The EH Kau2 had broad substrate specificity and preferentially hydrolyzed epoxides with S-configuration. It showed high enantioselectivity towards aromatic epoxides such as styrene oxide, p-nitrostyrene oxide, and trans-1-phenyl-1,2-epoxypropane. In addition, Kau2 showed enantioconvergent hydrolysis activity. The EH Kau8 also showed broad substrate specificity and preferentially hydrolyzed epoxides with R-configuration. High enantioselectivity was observed for p-nitrostyrene oxide, and the hydrolysis activity of Kau8 was less enantioconvergent than that of Kau2. To determine the usefulness of Kau2 for synthetic applications, preparative-scale biohydrolysis reactions were performed. Specifically, two kinetic resolutions were carried out with 80 g/L of racemic trans-1-phenyl-1,2-epoxypropane, affording both (1R,2R)-epoxide and the corresponding (1R,2S)-diol in high enantiomeric excess (>99%) and good yield (>45%). In addition, a process based on enantioconvergent hydrolysis by the EH Kau2 was established for racemic cis-1-phenyl-1,2-epoxypropane at a concentration of 13 g/L, resulting in the formation of the corresponding (1R,2R)-diol with a 97% yield and an enantiomeric excess exceeding 98%.
Iron-catalyzed olefin cis-dihydroxylation using a bio-inspired N,N, O-ligand
Oldenburg, Paul D.,Shteinman, Albert A.,Que Jr., Lawrence
, p. 15672 - 15673 (2005)
Nature has evolved enzymes that carry out the cis-dihydroxylation of C=C bonds in the biodegradation of arenes in the environment. These enzymes, called Rieske dioxygenases, have mononuclear iron centers coordinated to a 2-His-1-carboxylate facial triad motif that has emerged as a common structural element among many nonheme iron enzymes. In contrast, olefin cis-dihydroxylation is conveniently carried out by OsO4 and related species in synthetic procedures. To develop more environmentally benign strategies for carrying out these transformations, we have designed Ph-DPAH [(di-(2-pyridyl)methyl)benzamide], a tridentate ligand that mimics the facial N,N,O site of the mononuclear iron center in the Rieske dioxygenases. Its iron(II) complex has been found to catalyze olefin cis-dihydroxylation almost exclusively and with high H2O2 conversion efficiency on a wide range of substrates. and 18O labeling experiments suggest the participation of an FeV oxidant. Copyright
Chemical activation of a mononuclear non-porphyrinic manganese complex using water as oxygen source for the oxygen atom transfer reaction
El Kadiri, Moulay Youness,El Ghachtouli, Sanae,Guillot, Regis,Billon, Laurianne,Charlot, Marie-France,Framery, Eric,Andrioletti, Bruno,Aukauloo, Ally
, p. 2147 - 2150 (2012)
Water, a powerful ally: A MnIII complex with an N 4O-coordinating ligand and a deprotonated water molecule as sixth ligand is chemically oxidized by a CeIV one-electron oxidant. The results indicate catalytic oxygen atom transfer to alkenes, with the oxygen atom originating from a water molecule. These findings demonstrate the possibility of using water as oxygen source to perform the oxidation of organic substrates.
Direct Catalytic Transformation of Olefins into α-Hydroxy Ketones with Hydrogen Peroxide Catalyzed by Peroxotungstophosphate
Sakata, Yasuyuki,Katayama, Yuji,Ishii, Yasutaka
, p. 671 - 674 (1992)
Aliphatic olefins were directly converted into α-hydroxy ketones with acidic aqueous hydrogen peroxide in the presence of catalytic amount of peroxytungstophosphate (PCWP) under the biphasic system using chloroform as a solvent.The acidic medium was necessary to open the resulting epoxide to vic-diol which was subsequently oxidized to α-hydroxy ketones.
Catalytic Asymmetric Dihydroxylation of Aliphatic Olefins with Reusable Resin-Osmium Tetroxide
Choudary, Boyapati M.,Jyothi, Karangula,Madhi, Sateesh,Kantam, M. Lakshmi
, p. 1190 - 1192 (2003)
Asymmetric dihydroxylation of aliphatic olefins to chiral diols with good yields and ees by a heterogeneous Resin-OsO4 catalyst using ferricyanide as cooxidant is disclosed for the first time. The catalyst was recovered quantitatively by simple filtration and reused for several times without significant loss of activity.
Synthesis of di-nitrogen Schiff base complexes of methyltrioxorhenium(VII) and their application in epoxidation with aqueous hydrogen peroxide as oxidant
Gao, Yu,Zhang, Yuecheng,Qiu, Chuanjiang,Zhao, Jiquan
, p. 54 - 60 (2011)
Several di-nitrogen Schiff bases were synthesized through the condensation of 2-pyridinecarboxaldehyde with primary amines. The Schiff bases as ligands coordinated with methyltrioxorhenium (MTO) smoothly to afford the correspondent complexes which were characterized by IR, 1H NMR, 13C NMR, MS and elemental analysis. One of the complexes was analyzed by X-ray crystallography as well. The results revealed that the complexes display distorted octahedral geometry in the solid state with a trans-position of Schiff base. Catalytic results indicated that the complexes as catalysts increased the selectivity of epoxides remarkably compared with MTO in the epoxidation of alkenes with 30% hydrogen peroxide as oxidant and the increasing rate depended on the structure of the Schiff base ligands of the complexes. The results indicated that the stronger the donating ability of the ligand, the higher selectivity of epoxides the complex gave in the epoxidation of alkenes with 30% hydrogen peroxide as oxidant. Copyright
Ligand topology tuning of iron-catalyzed hydrocarbon oxidations
Costas, Miquel,Que Jr., Lawrence
, p. 2179 - 2181 (2002)
Quite unexpectedly, the topology of the tetradentate ligand in [FeII-(bpmcn)(OTf)2] (bpmcn = N,N′- bis-(2-pyridylmethyl)-N,N′-dimethyl-trans-1,2-diaminocyclohexane), whether cis-α or cis-β (see picture), determines the course of catalytic alkane hydroxylation and olefin oxidation reactions with H2O2, which afford products with varying stereo-selectivity and dramatically different sources of incorporated oxygen. These results demonstrate the exquisite role ligands can play in the fine tuning of the reactivity of an iron catalyst.
Niobium oxide and phosphoric acid impregnated silica-titania as oxidative-acidic bifunctional catalyst
Mohd Ekhsan, Jamilah,Lee, Siew Ling,Nur, Hadi
, p. 142 - 148 (2014)
Silica-titania modified by impregnation of niobium oxide and phosphoric acid (P/Nb/Ti-Si) possesses both oxidative active site and Br?nsted acid. Results of the catalytic evaluation in consecutive transformation of 1-octene to 1,2-octanediol through formation of 1,2-epoxyoctane suggested that Nb 2O5 was a more important oxidative active site compared to tetrahedral Ti species. Besides, co-existence of Nb2O5 and PO43- modifiers was crucial for Br?nsted acidity formation. However, the amount of Br?nsted acid created was strongly dependent on the synthesis method that was greatly influenced by the interfacial interaction between Nb2O5 and PO 43- in the material to produce NbOPO4 3-H+ bonding. It has been demonstrated that the P/Nb/Ti-Si was an excellent oxidative-acidic bifunctional catalyst to produce 1,2-octanediol.
High conversion of olefins to cis-diols by non-heme iron catalysts and H2O2.
Ryu, Ju Yeon,Kim, Jinheung,Costas, Miquel,Chen, Kui,Nam, Wonwoo,Que Jr., Lawrence
, p. 1288 - 1289 (2002)
Efficient and highly stereoselective oxidation of olefins to cis-diols as the major product is obtained by using biomimetic non-heme FeII catalysts in combination with H2O2.
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Emmons et al.
, p. 3472 (1954)
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Raw and waste plant materials as sources of fungi with epoxide hydrolase activity. Application to the kinetic resolution of aryl and alkyl glycidyl ethers
Dolcet, Marta,Torres, Mercè,Canela-Garayoa, Ramon
, p. 78 - 88 (2018)
The by-products of olive oil production can be used as sources of microbial strains. Penicillium sp., Aspergillus terreus, Penicillium aurantiogriseum, Aspergillus tubingensis and Aspergillus niger were selected on the basis of their epoxide-hydrolyzing activity towards racemic rac-glycidyl phenyl ether. We studied the effect on enzymatic activity of adding styrene oxide to the growth medium. It induced the biosynthesis of epoxide hydrolases and reduced cell growth. The resolution capacity of the five fungi was tested on rac-glycidyl phenyl ether, rac-benzyl glycidyl ether, rac-1,2-epoxyhexane and rac-1,2-epoxyoctane. The resolution of rac-glycidyl phenyl ether by A. niger, rac-benzyl glycidyl ether by P. aurantiogriseum and A. terreus, rac-1,2-epoxyhexane by A. tubingensis and rac-1,2-epoxyoctane by A. terreus provided (S)-3-phenoxy-1,2-propanediol (45.1% yield, 51.4% ee), (R)-3-benzyloxy-1,2-propanediol (40.8% yield, 43.3% ee), (S)-3-benzyloxy-1,2-propanediol (45.4% yield, 45.6% ee), (R)-1,2-hexanediol (70.4% yield, 24.4% ee) and (R)-1,2-octanediol (21.4% yield, 27.5% ee), respectively. The (R)-enantiopreference of the epoxide hydrolases from P. aurantiogriseum is unprecedented.
Iron-catalyzed olefin epoxidation in the presence of acetic acid: Insights into the nature of the metal-based oxidant
Mas-Balleste, Ruben,Que Jr., Lawrence
, p. 15964 - 15972 (2007)
The iron complexes [(BPMEN)Fe(OTf)2] (1) and [(TPA)Fe(OTf) 2] (2) [BPMEN = N,N′-bis-(2-pyridylmethyl)-N,N′-dimethyl- 1,2-ethylenediamine; TPA = tris-(2-pyridylmethyl)amine] catalyze the oxidation of olefins by H2O2 to yield epoxides and cis-diols. The addition of acetic acid inhibits olefin cis-dihydroxylation and enhances epoxidation for both 1 and 2. Reactions carried out at 0°C with 0.5 mol % catalyst and a 1:1.5 olefin/H2O2 ratio in a 1:2 CH 3CN/CH3COOH solvent mixture result in nearly quantitative conversions of cyclooctene to epoxide within 1 min. The nature of the active species formed in the presence of acetic acid has been probed at low temperature. For 2, in the absence of substrate, [(TPA)FeIII(OOH) (CH3COOH)]2+ and [(TPA)FeIVO(NCCH 3)]2+ intermediates can be observed. However, neither is the active epoxidizing species. In fact, [(TPA)FeIVO(NCCH 3)]2+ is shown to form in competition with substrate oxidation. Consequently, it is proposed that epoxidation is mediated by [(TPA)FeV(O)(OOCCH3)]2+, generated from O-O bond heterolysis of the [(TPA)FeIII(OOH)(CH3COOH)] 2+ intermediate, which is promoted by the protonation of the terminal oxygen atom of the hydroperoxide by the coordinated carboxylic acid.
Iridium-promoted conversion of terminal epoxides to primary alcohols under acidic conditions using hydrogen
Rainsberry, Alena N.,Sage, Jarrod G.,Scheuermann, Margaret L.
, p. 3020 - 3022 (2019)
A strategy for the conversion of terminal epoxides to primary alcohols is presented. The reaction uses hydrogen as the only stoichiometric reagent and is promoted by an iridium precatalyst under acidic conditions. Selectivity for the formation of a terminal alcohol over an internal alcohol is observed for both alkyl- and aryl-substituted terminal epoxides in isolated yields of up to 50% and 72% respectively.
Atom-efficient oxidation of alkenes with molecular oxygen: Synthesis of diols
Doebler, Christian,Mehltretter, Gerald,Beller, Matthias
, p. 3026 - 3028 (1999)
Dihydroxylations of simple alkenes were carried out for the first time in excellent yields and selectivities with molecular oxygen as oxidant [(Eq. (a)]. Both oxygen atoms are used productively and are incorporated into the product in this transition metal catalyzed alkene oxidation.
Absolute configuration of octanol derivatives in apple fruits
Beuerle, Till,Schreier, Peter,Brunerie, Pascal,Bicchi, Carlo,Schwab, Wilfried
, p. 145 - 149 (1996)
In extracts obtained by liquid liquid extraction and enzymatic hydrolysis from five apple cultivars (Renao; Bedan; Peau de Chien; Noel des Champs: Red Delicious), chiral evaluation of free and glycosidically-bound octaner-1,3-diol and 5(Z)-octene-1,3-diol, as well as ethyl 3- hydroxyoctanoate and ethyl 5(Z)-3-hydroxy-octenoate, was performed by multidimensional gas chromatography (MDGC), combining a polar achiral column (DB-Wax) with a chiral main column (2,3-di-O-acetyl-6-O-tert. butyldimethylsilyl-β-cyclodextrin/OV 1701). Comparison of retention times of synthesized optically-enriched reference compounds with isolated diols and hydroxyesters, revealed the (R)-configuration for the free diols in cvs. Renao, Bedan, Peau de Chien and Noel des Champs and the (R)-configuration for the bound diols in cvs Bedan. Peau de Chien and Noel des Champs, exhibiting enantiomeric excesses tees) greater than 99%. (R)-hydroxyesters (ee > 99%) were detected in cvs. Noel des Champs and Red Delicious.
Enantioselective synthesis of terminal 1,2-diols from acyl chlorides
Shao, Panlin,Shen, Litao,Ye, Song
, p. 2688 - 2692 (2012)
Optically active terminal 1,2-diols were prepared with high enantiopurity via the TMS-quinidine-catalyzed enantioselective cyclization of acyl chlorides and oxaziridine, followed by reductive ring-opening of the cycloadducts.
A new practical method for the osmium-catalyzed dihydroxylation of olefins using bleach as the terminal oxidant
Mehltretter, Gerald M.,Bhor, Santosh,Klawonn, Markus,D?bler, Christian,Sundermeier, Uta,Eckert, Markus,Militzer, Hans-Christian,Beller, Matthias
, p. 295 - 301 (2003)
A general procedure for the osmium-catalyzed dihydroxylation of various olefins using bleach as oxidant is reported for the first time. Aromatic and aliphatic olefins yield the corresponding cis-1,2-diols in the presence of dihydroquinine or dihydroquinidine derivatives (Sharpless ligands) with good to excellent chemo- and enantioselectivities under optimized pH conditions. In the presence of a small excess of bleach as reoxidant fast dihydroxylation takes place even at 0°C. Under optimum reaction conditions it is possible to dihydroxylate terminal aliphatic and aromatic olefins as well as internal olefins. The low price of the oxidant and the simple handling of bleach make this dihydroxylation variant attractive for further applications.
Catalytic oxygen atom transfer promoted by tethered Mo(VI) dioxido complexes onto silica-coated magnetic nanoparticles
Colaiezzi, Roberta,Crucianelli, Marcello,Di Giuseppe, Andrea,Ferella, Francesco,Lazzarini, Andrea,Paolucci, Valentina
, (2021/11/30)
The preparation of three novel active and stable magnetic nanocatalysts for the selective liquid-phase oxidation of several olefins, has been reported. The heterogeneous systems are based on the coordination of cis-MoO2 moiety onto three different SCMNP@Si-(L1-L3) magnetically active supports, functionalized with silylated acylpyrazolonate ligands L1, L2 and L3. Nanocatalysts thoroughly characterized by ATR-IR spectroscopy, TGA and ICP-MS analyses, showed excellent catalytic performances in the oxidation of conjugated or unconjugated olefins either in organic or in aqueous solvents. The good magnetic properties of these catalytic systems allow their easy recyclability, from the reaction mixture, and reuse over five runs without significant decrease in the activity, either in organic or water solvent, demonstrating their versatility and robustness.
A stand-alone cobalt bis(dicarbollide) photoredox catalyst epoxidates alkenes in water at extremely low catalyst load
Guerrero, Isabel,Romero, Isabel,Teixidor, Francesc,Vi?as, Clara
supporting information, p. 10123 - 10131 (2021/12/27)
The cobalt bis(dicarbollide) complex, Na[3,3′-Co(η5-1,2-C2B9H11) (Na[1]), is an effective photoredox catalyst for the oxidation of alkenes to epoxides in water. Advantageous features of Na[1] include its lack of photoluminescence, high solubility and surfactant behavior in aqueous media, as well as the donor ability of the carborane ligand and high oxidizing power of the Co4+/3+ couple. These features differentiate it from the well-known and widely used photosensitizer tris (2,2′-bipyridine) ruthenium(ii) ([Ru(bpy)3]2+), which also participates in electron transfer through an outer sphere mechanism. A comparison of the catalytic performance of [Ru(bpy)3]2+ with Na[1] for alkene photo-oxidation is fully in favor of Na[1], as the former shows very low or null efficiency. With a catalyst loading of 0.1 mol% conversions between 65-97% have been obtained in short reaction times, 15 minutes, with moderate selectivity for the corresponding epoxide, due to the formation of side products as diols. But when the catalyst loading is reduced to 0.01 mol%, the selectivity for the corresponding epoxide increased considerably, being the only compound formed after 15 minutes of reaction (selectivity >99%). High TON values have been obtained (TON = 8500) for the epoxidation of aromatic and aliphatic alkenes in water. We have verified that Na[3,3′-Co(η5-1,2-C2B9H11)2] acts as a photocatalyst in both the epoxidation of alkenes and in their hydroxylation in aqueous medium with a higher rate for epoxidation than for hydroxylation. Preliminary photooxidation tests using methyl oleate as the substrate led to the selective epoxidation of the double bond. These results represent a promising starting point for the development of practical methods for the processing of unsaturated fatty acids, such as the valorisation of animal fat waste using this sustainable photoredox catalyst. This journal is
Understanding the mechanism of N coordination on framework Ti of Ti-BEA zeolite and its promoting effect on alkene epoxidation reaction
Liang, Xiaohang,Liu, Dan,Luo, Yibin,Peng, Xinxin,Shu, Xingtian,Xia, Changjiu
, (2021/07/31)
The function of ammonium salts on the epoxidation performance over Ti-BEA zeolite was investigated in detail. Experiments of alkene epoxidation, side reactions of epoxide and decomposition of H2O2 with or without ammonium salts were designed, and the UV-Vis spectroscopy was employed to analyze the structure of Ti-hydroperoxo species. It is revealed that the ammonia (or amines) dissociated from the ammonium salt would chelate with the linear Ti-η1(OOH) species and form a bridged Ti-η2(OOH)-R species, which is more stable, more weaker in epoxide adsorption and acidity as well. Therefore, side reactions and H2O2 decomposition would be suppressed, and both alkene conversion and epoxide selectivity would be promoted simultaneously. On the other hand, the excessive NH3?H2O (NH3/Ti>1) or NaOH bond with the Ti-η2(OOH)-R species and generate salt-like Ti-η2(OO)-M+ species, resulting in the deactivation of Ti active center. While for ammonium salts, e.g. NH4Cl, the limited dissociation degree along with the acidic environment help the Ti active center to maintain in highly active. In short, this work provides a practical Ti active center tuning method for Ti-BEA zeolite, as well as a thorough understanding of its Ti-hydroperoxo species.
