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Understanding the Structure–Polymerization Thermodynamics Relationships of Fused-Ring Cyclooctenes for Developing Chemically Recyclable Polymers
Polymers that can be chemically recycled to their constituent monomers offer a promising solution to address the challenges in plastics sustainability through a circular use of materials. The design and development of monomers for next-generation chemical
Sathe, Devavrat,Wang, Junpeng,Zhou, Junfeng
supporting information
p. 928 - 934
(2022/01/19)

MONOACYLGLYCEROL LIPASE MODULATORS
Fused and bridged compounds of Formula (I), and pharmaceutically acceptable salts, isotopes, N-oxides, solvates, and stereoisomers thereof, pharmaceutical compositions containing them, methods of making them, and methods of using them including methods for treating disease states, disorders, and conditions associated with MGL modulation, such as those associated with pain, psychiatric disorders, neurological disorders (including, but not limited to major depressive disorder, treatment resistant depression, anxious depression, autism spectrum disorders, Asperger syndrome, bipolar disorder), cancers and eye conditions: (I) wherein R1a, R1b, R2, and R3, are defined herein.
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(2021/10/02)

COMPOSITIONS AND METHODS FOR DELIVERING A SUBSTANCE TO A BIOLOGICAL TARGET
The present application provides compositions and methods using bioorthogonal inverse electron demand Diels-Alder cycloaddition reaction for rapid and specific covalent delivery of a payload to a ligand bound to a biological target.
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Paragraph 0110; 0111

(2020/03/26)

Monoacylglycerol Lipase Modulators
Bridged compounds of Formula (I) and Formula (II), pharmaceutical compositions containing them, methods of making them, and methods of using them including methods for treating disease states, disorders, and conditions associated with MGL modulation, such as those associated with pain, psychiatric disorders, neurological disorders (including, but not limited to major depressive disorder, treatment resistant depression, anxious depression, bipolar disorder), cancers and eye conditions. wherein R2, R3 R4, R5 and R6 are defined herein.
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Paragraph 0410; 0437

(2020/04/24)

A Bioorthogonal Click Chemistry Toolbox for Targeted Synthesis of Branched and Well-Defined Protein–Protein Conjugates
Bioorthogonal chemistry holds great potential to generate difficult-to-access protein–protein conjugate architectures. Current applications are hampered by challenging protein expression systems, slow conjugation chemistry, use of undesirable catalysts, or often do not result in quantitative product formation. Here we present a highly efficient technology for protein functionalization with commonly used bioorthogonal motifs for Diels–Alder cycloaddition with inverse electron demand (DAinv). With the aim of precisely generating branched protein chimeras, we systematically assessed the reactivity, stability and side product formation of various bioorthogonal chemistries directly at the protein level. We demonstrate the efficiency and versatility of our conjugation platform using different functional proteins and the therapeutic antibody trastuzumab. This technology enables fast and routine access to tailored and hitherto inaccessible protein chimeras useful for a variety of scientific disciplines. We expect our work to substantially enhance antibody applications such as immunodetection and protein toxin-based targeted cancer therapies.
Baalmann, Mathis,Bitsch, Sebastian,Deweid, Lukas,Ilkenhans, Nadja,Kolmar, Harald,Neises, Laura,Schneider, Hendrik,Werther, Philipp,Wilhelm, Jonas,Wolfring, Martin,Wombacher, Richard,Ziegler, Michael J.
supporting information
p. 12885 - 12893
(2020/06/02)

Preparation of cubic-shaped sorafenib-loaded nanocomposite using well-defined poly(vinyl alcohol alt-propenylene) copolymer
Vinyl alcohol (VA) copolymers having fine tunable polarities are emerging materials in drug delivery applications. VA copolymers rendering well-defined molecular architecture (C/OH ratio = 2, 4, 5 and 8) were used as carriers for model drug compound, fluorescein, which exhibited significantly different release characteristics depending on the polarity of the polymers. Based on the preliminary drug release tests the well-defined VA copolymer having C/OH = 5 ratio, poly(vinyl alcohol alt-propenylene) copolymer (PVA-5) was selected for nanocomposite synthesis. Sorafenib anticancer drug was embedded into PVA-5 (C/OH = 5 ratio) nanoparticles by nanoprecipitation resulting in nanoparticles exhibiting unusual cubic shape. The sorafenib-loaded nanocomposites showed continuous release during a day and concentration-dependant cytotoxicity on HT-29 cancer cells. This might be interpreted by the sustained release of the drug.
Feczkó, Tivadar,Merza, Gabriella,Babos, Gy?rgy,Varga, Bernadett,Gyetvai, Eszter,Trif, László,Kovács, Ervin,Tuba, Robert
p. 333 - 341
(2019/04/04)

Aerobic oxidation of the C-H bond under ambient conditions using highly dispersed Co over highly porous N-doped carbon
Highly dispersed Co sites in highly porous N-doped carbon (Co-NC) were synthesized by high-temperature pyrolysis of Zn/Co bimetallic zeolitic imidazolate framework-8 (CoxZn100-x-ZIF). Wide characterization indicated that the pyrolysis atmosphere and temperature play crucial roles in the metal dispersion and pore structure of the resulting materials. A hydrogen treatment at elevated temperatures is found to favour the Zn volatilization and restrict the pore shrinkage of the ZIF precursor, thus yielding efficient catalysts with highly dispersed Co, a high surface area (1090 m2 g-1) and pore volume (0.89 cm3 g-1). When used as a catalyst for aerobic oxidation of ethylbenzene (EB), Co1Zn99-ZIF-800-H2 contributes to 98.9% EB conversion and 93.1% ketone selectivity under mild conditions (60 °C, 1 atm O2), which is 41.3 times more active in comparison to the ZIF-67-derived Co catalyst. Co-NC is stable and could be reused four times without obvious deactivation. This catalyst displays good chemoselectivity to the corresponding ketones when using a broad scope of hydrocarbon compounds.
Nie, Renfeng,Chen, Jingwen,Chen, Minda,Qi, Zhiyuan,Goh, Tian-Wei,Ma, Tao,Zhou, Lin,Pei, Yuchen,Huang, Wenyu
p. 1461 - 1466
(2019/03/26)

Synthesis of functionalized carbon microspheres and their catalyst activity in C—O and C—N bond formation reactions
Disclosed herein is a simple process for functionalization/grafting of carbon microspheres obtained from bagasse with various active functional groups onto it and use of the same as catalyst for various organic reactions, having very high selectivity and conversion rate.
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(2019/02/14)

Photocatalytic Aerobic Phosphatation of Alkenes
A catalytic regime for the direct phosphatation of simple, non-polarized alkenes has been devised that is based on using ordinary, non-activated phosphoric acid diesters as the phosphate source and O2 as the terminal oxidant. The title method enables the direct and highly economic construction of a diverse range of allylic phosphate esters. From a conceptual viewpoint, the aerobic phosphatation is entirely complementary to traditional methods for phosphate ester formation, which predominantly rely on the use of prefunctionalized or preactivated reactants, such as alcohols and phosphoryl halides. The title transformation is enabled by the interplay of a photoredox and a selenium π-acid catalyst and involves a sequence of single-electron-transfer processes.
Depken, Christian,Kr?tzschmar, Felix,Rieger, Rene,Rode, Katharina,Breder, Alexander
supporting information
p. 2459 - 2463
(2018/01/27)

Identification of in situ flower volatiles from kiwifruit (Actinidia chinensis var. deliciosa) cultivars and their male pollenisers in a New Zealand orchard
In situ flower volatiles from six kiwifruit cultivars (Actinidia chinensis var. deliciosa); ‘Hayward’, ‘Chieftain’, ‘M56’, ‘Zes007’ (Green11), ‘M36’, and ‘M43’ were collected by dynamic headspace sampling. Forty-five compounds were detected in the headspace of the flowers, with straight chain hydrocarbons and terpenes accounting for >98% of the volatiles emitted quantitatively across the six cultivars. Of these hydrocarbons, (3Z,6Z,9Z)-heptadecatriene is reported for the first time from a floral source while (8Z)-hexadecene and (9Z)-nonadecene are reported for the first time from kiwifruit flowers. All three hydrocarbons were verified by synthesis. Quantitative comparison of the six honey bee perceived compounds from the headspace of the cultivars showed that the males ‘M36’ and ‘M43’ closely matched the female cultivar Green11 that they are used to pollinate. Males ‘M56’ and ‘Chieftain’ were not as closely matched to the female cultivar ‘Hayward’ that they are used to pollinate. The male ‘M56’ in particular differed significantly from the female ‘Hayward’ in four of the six honey bee perceived compounds.
Twidle, Andrew M.,Suckling, David M.,Seal, Alan G.,Fedrizzi, Bruno,Pilkington, Lisa I.,Barker, David
p. 61 - 69
(2017/05/31)

New multiblock copolymers of norbornene and 5-hydroxycyclooctene
Cross-metathesis of 5-hydroxycyclooctene and norbornene homopolymers affords the multiblock copolymer possessing a broad range in the degree of blockiness (from 0.03 to 1).
Denisova, Yulia I.,Gringolts, Maria L.,Roenko, Alexei V.,Shandryuk, Georgiy A.,Finkelshtein, Eugene Sh.,Kudryavtsev, Yaroslav V.
p. 416 - 418
(2017/08/02)

Synthesis of ethylene/vinyl ester copolymers with pendent linear branches via ring-opening metathesis polymerization of fatty acid-derived cyclooctenes
Fatty acid-derived cyclooctenes, including n-hexanoic acid (M1), n-octanoic acid (M2), lauric acid (M3), and palmitic acid (M4), were prepared as monomers and polymerized by ring-opening metathesis polymerization (ROMP) using Grubbs second-generation cata
Feng, Yuchen,Jie, Suyun,Li, Bo-Geng
p. 2211 - 2220
(2017/05/16)

Novel Super-Resolution Imaging Compositions and Methods Using Same
The invention provides compositions that may be used for imaging intracellular structures. The invention further provides methods of imaging intracellular structures. In certain embodiments, the compositions of the invention include trans-cyclooctene-containing ceramide lipids and tetrazine-containing rhodamine-related dyes.
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Paragraph 0139

(2016/05/24)

Co(ii) complexes loaded into metal-organic frameworks as efficient heterogeneous catalysts for aerobic epoxidation of olefins
A series of efficient cobalt(ii)-anchored Cr-MOF (Cr-MIL-101-NH2) catalysts, such as Co(ii)@Cr-MIL-101-Sal, Co(ii)@Cr-MIL-101-P2I and Co(ii)@Cr-MIL-101-P3I, have been successfully synthesized by one-pot modification of the terminal amino group with salicylaldehyde, pyridine-2-aldehyde or pyridine-3-aldehyde and anchoring of Co(ii) ions into the mesoporous Cr-MOF supports. The Co(ii)@Cr-MIL-101-P2I catalyst exhibited high catalytic performance for epoxidation of olefins with air as an oxidant due to the nitrogen atom in the pyridine ring as a strong electron-withdrawing substituent, high dispersion of Co(ii) species and high surface area for sufficient contact between the substrate and active sites. The strong coordination interaction between the Co(ii) ions and chelating groups in the Co(ii)@Cr-MIL-101-P2I catalyst guaranteed the excellent recycling performance. Furthermore, the synthesized Co(ii)@Cr-MIL-101-P2I catalyst realized its general applicability towards various olefins, such as cyclic olefins, tri-substituted olefins, aliphatic olefins and aromatic olefins.
Wang, Jingjing,Yang, Mu,Dong, Wenjun,Jin, Zhaokui,Tang, Jia,Fan, Shuang,Lu, Yunfeng,Wang, Ge
p. 161 - 168
(2015/12/31)

Design and preparation of a polymer resin-supported organoselenium catalyst with industrial potential
Hexavalent Se? Yes! Selenium on polymers exhibits quite different properties compared to that in small molecules. Hexavalent Se, rare in organoselenium chemistry, was found to be the major species on polymers. The high-valent Se species on recyclable polymer resins could quickly catalyze the oxidation reaction of cyclohexene with H2O2 in water to produce industrially important intermediate trans-1,2-cyclohexanediol in almost quantitative yield. In the catalytic cycle, high valent Se species were reduced to divalent Se, a highly activated species that could be re-oxidized by air so that no excess H2O2 was required for the reaction. The results were superior to those of reactions catalyzed by small molecules, for which excess H2O2, long reaction time or expensive CF3-activated catalysts and environmentally unfriendly MeCN solvent were required.
Wang, Yuguang,Yu, Lihua,Zhu, Bingchun,Yu, Lei
supporting information
p. 10828 - 10833
(2016/07/21)

Electronic Structure and Multicatalytic Features of Redox-Active Bis(arylimino)acenaphthene (BIAN)-Derived Ruthenium Complexes
The article examines the newly designed and structurally characterized redox-active BIAN-derived [Ru(trpy)(R-BIAN)Cl]ClO4 ([1a]ClO4-[1c]ClO4), [Ru(trpy)(R-BIAN)(H2O)](ClO4)2 ([3a](ClO4)2-[3c](ClO4)2), and BIAO-derived [Ru(trpy)(BIAO)Cl]ClO4 ([2a]ClO4) (trpy = 2,2′:6′,2′′-terpyridine, R-BIAN = bis(arylimino)acenaphthene (R = H (1a+, 3a2+), 4-OMe (1b+, 3b2+), 4-NO2 (1c+, 3c2+), BIAO = [N-(phenyl)imino]acenapthenone). The experimental (X-ray, 1H NMR, spectroelectrochemistry, EPR) and DFT/TD-DFT calculations of 1an-1cn or 2an collectively establish {RuII-BIAN0} or {RuII-BIAO0} configuration in the native state, metal-based oxidation to {RuIII-BIAN0} or {RuIII-BIAO0}, and successive electron uptake processes by the α-diimine fragment, followed by trpy and naphthalene π-system of BIAN or BIAO, respectively. The impact of the electron-withdrawing NO2 function in the BIAN moiety in 1c+ has been reflected in the five nearby reduction steps within the accessible potential limit of -2 V versus SCE, leading to a fully reduced BIAN4- state in [1c]4-. The aqua derivatives ({RuII-OH2}, 3a2+-3c2+) undergo simultaneous 2e-/2H+ transfer to the corresponding {RuIV-O} state and the catalytic current associated with the RuIV/RuV response probably implies its involvement in the electrocatalytic water oxidation. The aqua derivatives (3a2+-3c2+) are efficient and selective precatalysts in transforming a wide variety of alkenes to corresponding epoxides in the presence of PhI(OAc)2 as an oxidant in CH2Cl2 at 298 K as well as oxidation of primary, secondary, and heterocyclic alcohols with a large substrate scope with H2O2 as the stoichiometric oxidant in CH3CN at 343 K. The involvement of the {RuIV-O} intermediate as the active catalyst in both the oxidation processes has been ascertained via a sequence of experimental evidence.
Singha Hazari, Arijit,Ray, Ritwika,Hoque, Md Asmaul,Lahiri, Goutam Kumar
p. 8160 - 8173
(2016/08/24)

Synthesis of 1,3-Cycloalkadienes from Cycloalkenes: Unprecedented Reactivity of Oxoammonium Salts
Few methods allow for the direct conversion of cycloalkenes into cycloalkadienes with high chemo- and regioselectivity. Herein, we report a convenient one-pot process for this transformation that involves the unprecedented N-preferential group transfer of N-oxoammonium salts to cycloalkenes, followed by Cope elimination, to afford cycloalkadienes at room temperature and pressure.
Nagasawa, Shota,Sasano, Yusuke,Iwabuchi, Yoshiharu
supporting information
p. 13189 - 13194
(2016/10/30)

Precision Polyketones by Ring-Opening Metathesis Polymerization: Effects of Regular and Irregular Ketone Spacing
The synthesis and characterization of regioregular aliphatic polyketones is reported. Poly(1-oxoheptamethylene), a semicrystalline polyketone, was prepared via ruthenium-catalyzed ring-opening metathesis polymerization (ROMP) of a ketal-protected 7-membered cyclic ketone followed by subsequent hydrogenation and deprotection. Temperature and catalyst studies of the ROMP reaction guided the preparation of polyketones with high monomer conversions, molecular weights as high as 30 kDa, and dispersities as low as 1.4. Because of the symmetric nature of the monomer, the polymer has ketones spaced every six methylene units apart. The thermal properties of this polyketone were investigated by differential scanning calorimetry, revealing a peak melting range of 160-165 °C. A related polymer, poly(1-oxooctamethylene), was also prepared in a similar fashion, and a peak melting range of only 130-133 °C was observed. This difference in melting range is attributed to the lack of the regioregularity in poly(1-oxooctamethylene), which was derived from an asymmetric 8-membered ring monomer and has ketones spaced every 6, 7, or 8 methylene units apart.
Arrington, Kyle J.,Murray, Clifton B.,Smith, Emily C.,Marand, Hervé,Matson, John B.
p. 3655 - 3662
(2016/06/09)

PYRAZOLOPYRIMIDINE INHIBITORS OF IRAK4 ACTIVITY
The present invention relates to pyrazolopyrimidine inhibitors of IRAK4 of formula (I) and provides compositions comprising such inhibitors, as well as methods therewith for treating IRAK4-mediated or -associated conditions or diseases.
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(2016/09/26)

Tunable Electrochemical and Catalytic Features of BIAN- and BIAO-Derived Ruthenium Complexes
This article deals with a class of ruthenium-BIAN-derived complexes, [RuII(tpm)(R-BIAN)Cl]ClO4 (tpm = tris(1-pyrazolyl)methane, R-BIAN = bis(arylimino)acenaphthene, R = 4-OMe ([1a]ClO4), 4-F ([1b]ClO4), 4-Cl ([1c]ClO4), 4-NO2 ([1d]ClO4)) and [RuII(tpm)(OMe-BIAN)H2O]2+ ([3a](ClO4)2). The R-BIAN framework with R = H, however, leads to the selective formation of partially hydrolyzed BIAO ([N-(phenyl)imino]acenapthenone)-derived complex [RuII(tpm)(BIAO)Cl]ClO4 ([2]ClO4). The redox-sensitive bond parameters involving -N=C-C=N- or -Ni=C-C=O of BIAN or BIAO in the crystals of representative [1a]ClO4, [3a](PF6)2, or [2]ClO4 establish its unreduced form. The chloro derivatives 1a+-1d+ and 2+ exhibit one oxidation and successive reduction processes in CH3CN within the potential limit of ±2.0 V versus SCE, and the redox potentials follow the order 1a+ + + + ≈ 2+. The electronic structural aspects of 1an-1dn and 2n (n = +2, +1, 0, -1, -2, -3) have been assessed by UV-vis and EPR spectroelectrochemistry, DFT-calculated MO compositions, and Mulliken spin density distributions in paramagnetic intermediate states which reveal metal-based (RuII → RuIII) oxidation and primarily BIAN- or BIAO-based successive reduction processes. The aqua complex 3a2+ undergoes two proton-coupled redox processes at 0.56 and 0.85 V versus SCE in phosphate buffer (pH 7) corresponding to {RuII-H2O}/{RuIII-OH} and {RuIII-OH}/{RuIV=O}, respectively. The chloro (1a+-1d+) and aqua (3a2+) derivatives are found to be equally active in functioning as efficient precatalysts toward the epoxidation of a wide variety of alkenes in the presence of PhI(OAc)2 as oxidant in CH2Cl2 at 298 K, though the analogous 2+ remains virtually inactive. The detailed experimental analysis with the representative precatalyst 1a+ suggests the involvement of the active {RuIV=O} species in the catalytic cycle, and the reaction proceeds through the radical mechanism, as also supported by the DFT calculations.
Hazari, Arijit Singha,Das, Ankita,Ray, Ritwika,Agarwala, Hemlata,Maji, Somnath,Mobin, Shaikh M.,Lahiri, Goutam Kumar
p. 4998 - 5012
(2015/05/27)

Non-peripherally alkyl substituted ruthenium phthalocyanines as catalysts in the epoxidation of alkenes
Non-peripherally alkyl substituted ruthenium phthalocyanines were demonstrated to be highly active epoxidation catalysts. It is compatible with pyridine N-oxides, and especially 2,6-dichloropyridine N-oxide. The catalytic activity towards a variety of alkenes was comparable to that published for other catalytic systems, but superior in the cases of 1,2-dihydronaphthalene and trans-stilbene. Linear substituents on the non-peripheral sites of the phthalocyanine were able to reduce aggregation and increase the solubility of the catalyst without compromising its activity by steric congestion as all substituted catalysts were more reactive than the unsubstituted phthalocyanine, whereas the bulky isopentyl and cyclohexyl substituted catalysts were less active than those with linear substituents. Although the epoxidation mechanism and the exact active intermediate is still ambigious, it likely involves the coordination of the N-oxide to ruthenium and subsequent transfer of the oxygen to the metal to form a high-valent oxo-ruthenium species. It is proposed that the alkene approaches this metal oxo moiety from the top and that oxygen transfer to the alkene is concerted with concomitant stereoretention.
Enow, Charles A.,Marais, Charlene,Bezuidenhoudt, Barend C.B.
p. 582 - 594
(2015/05/05)

Enhancing Mechanical Performance of a Covalent Self-Healing Material by Sacrificial Noncovalent Bonds
Polymers that repair themselves after mechanical damage can significantly improve their durability and safety. A major goal in the field of self-healing materials is to combine robust mechanical and efficient healing properties. Here, we show that incorporation of sacrificial bonds into a self-repairable network dramatically improves the overall mechanical properties. Specifically, we use simple secondary amide side chains to create dynamic energy dissipative hydrogen bonds in a covalently cross-linked polymer network, which can self-heal via olefin cross-metathesis. We envision that this straightforward sacrificial bonding strategy can be employed to improve mechanical properties in a variety of self-healing systems. (Graph Presented).
Neal, James A.,Mozhdehi, Davoud,Guan, Zhibin
supporting information
p. 4846 - 4850
(2015/04/27)

Silica microspheres containing high density surface hydroxyl groups as efficient epoxidation catalysts
Uniformly sized silica microspheres were synthesized by a hydrolysis-condensation method. The obtained material was etched with a mild aqueous potassium hydroxide solution for different periods of time to break their Si-O-Si bonds and increases the density of hydroxyl groups on their surfaces. The resulting materials were then used as transition metal-free catalysts for oxidation of olefins in the presence of hydrogen peroxide as a green oxidant. The materials were thoroughly characterized using various physicochemical techniques. These highly populated hydroxyl groups on the surface of silica microspheres were proven to be responsible for excellent conversion (up to 93%) and epoxide selectivity (up to 100%) for various olefins. Quantum mechanical calculations also corroborate the experimental findings. Furthermore, both experimental and theoretical studies show that tertiary silanols were present at the active sites of the catalyst surface and were responsible for olefin epoxidation.
Chandra, Prakash,Doke, Dhananjay S.,Umbarkar, Shubhangi B.,Vanka, Kumar,Biradar, Ankush V.
p. 21125 - 21131
(2015/03/30)

Epoxidation of strained alkenes catalysed by (1,2-dimethyl-4(1H)pyridinone-3-olate)2MnIIICl
The mild epoxidation of strained alkenes using (DMPO)2MnCl catalyst (DMPO = 1,2-dimethyl-4(1H)-pyridinone-3-olate) in the presence of various oxidants was studied. Hydrogen peroxide and monopersulfate were found to be the best oxidants when used with imidazole in acetonitrile at 4 °C, with up to 94% conversion. Dismutation of hydrogen peroxide was also observed when used as an oxidant. The epoxidation using hydrogen peroxide or monoperoxysulfate appears to be mild and very selective for strained alkenes. A mechanism is proposed where imidazole is required for activation of the oxidant and where a detected MnV = O species is proposed as the active species. Competitive reaction between H2O2 and the substrate for the active species is proposed and homolytic vs heterolytic scissions of the OO bond of the oxidant are discussed.
Robinson-Miller, Adam P.,Wyatt, Mark F.,Tétard, David
p. 376 - 390
(2015/01/30)

Regioselective Cleavage of Electron-Rich Double Bonds in Dienes to Carbonyl Compounds with [Fe(OTf)2(mix-BPBP)] and a Combination of H2O2 and NaIO4
A method for the regioselective transformation of dienes to carbonyl compounds has been developed. Electron-rich olefins react selectively to yield valuable aldehydes and ketones. The method is based on the catalyst [Fe(OTf)2(mix-BPBP)] with an oxidant combination of H2O2 (1.0 equiv.) and NaIO4 (1.5 equiv.); it uses mild conditions and short reaction times, and it outperforms other olefin cleavage methodologies. The combination of an Fe-based catalyst, [Fe(OTf)2(mix-BPBP)], and the oxidants H2O2 and NaIO4 can discriminate between electronically different double bonds and oxidatively cleave the electron-rich bond in dienes to yield aldehydes and ketones in a regioselective manner. The reaction requires mild conditions (0-50 C) and short reaction times (70 min).
Spannring, Peter,Yazerski, Vital A.,Chen, Jianming,Otte, Matthias,Weckhuysen, Bert M.,Bruijnincx, Pieter C. A.,Klein Gebbink, Robertus J. M.
p. 3462 - 3466
(2015/08/06)

Super-resolution imaging of the Golgi in live cells with a bioorthogonal ceramide probe
We report a lipid-based strategy to visualize Golgi structure and dynamics at super-resolution in live cells. The method is based on two novel reagents: a trans-cyclooctene-containing ceramide lipid (Cer-TCO) and a highly reactive, tetrazine-tagged near-IR dye (SiR-Tz). These reagents assemble via an extremely rapid "tetrazine-click" reaction into Cer-SiR, a highly photostable "vital dye" that enables prolonged live-cell imaging of the Golgi apparatus by 3D confocal and STED microscopy. Cer-SiR is nontoxic at concentrations as high as 2 μM and does not perturb the mobility of Golgi-resident enzymes or the traffic of cargo from the endoplasmic reticulum through the Golgi and to the plasma membrane.
Erdmann, Roman S.,Takakura, Hideo,Thompson, Alexander D.,Rivera-Molina, Felix,Allgeyer, Edward S.,Bewersdorf, Joerg,Toomre, Derek,Schepartz, Alanna
supporting information
p. 10242 - 10246
(2015/03/31)

Molybdenum-MCM-41 silica as heterogeneous catalyst for olefin epoxidation
MCM-41-supported molybdenum/bis-dithiocarbamate complex can be efficiently utilized, after treatment with tert-butylhydroperoxide (TBHP), for the epoxidation of alkenes under solventless conditions. The treatment with TBHP allows the formation of the real catalyst through oxidative decomposition of the complex affording well dispersed Mo(VI) species grafted onto the silica surface through the silanol groups. Experimental results, catalytic efficiency and spectroscopy data, allow to advance some hypotheses on the molybdenum-grafted catalyst formation. The grafted catalyst can be reused several times in the model epoxidation of cyclohexene affording the epoxide with very good yield; only during the first run a modest molybdenum leaching is observed. Both cyclic and linear alkenes can be epoxidized in good to excellent yields and selectivities.
Bigi, Franca,Piscopo, Calogero Giancarlo,Predieri, Giovanni,Sartori, Giovanni,Scotti, Roberto,Zanoni, Robertino,Maggi, Raimondo
p. 108 - 113
(2014/04/17)

A remote stereochemical lever arm effect in polymer mechanochemistry
Molecular mechanisms by which to increase the activity of a mechanophore might provide access to new chemical reactions and enhanced stress-responsive behavior in mechanochemically active polymeric materials. Here, single-molecule force spectroscopy reveals that the force-induced acceleration of the electrocyclic ring opening of gem-dichlorocyclopropanes (gDCC) is sensitive to the stereochemistry of an α-alkene substituent on the gDCC. On the ～0.1 s time scale of the experiment, the force required to open the E-alkene-substituted gDCC was found to be 0.4 nN lower than that required in the corresponding Z-alkene isomer, despite the effectively identical force-free reactivities of the two isomers and the distance between the stereochemical permutation and the scissile bond of the mechanophore. Fitting the experimental data with a cusp model provides force-free activation lengths of 1.67 ± 0.05 and 1.20 ± 0.05 ? for the E and Z isomers, respectively, as compared to 1.65 and 1.24 ? derived from computational modeling.
Wang, Junpeng,Kouznetsova, Tatiana B.,Kean, Zachary S.,Fan, Lin,Mar, Brendan D.,Martnez, Todd J.,Craig, Stephen L.
supporting information
p. 15162 - 15165
(2015/01/16)

TiO2 nanomaterials: Highly active catalysts for the oxidation of hydrocarbons
TiO2 nanomaterials (nanoparticles, nanotubes and nanofibers) are active and selective heterogeneous catalysts for the oxidation of hydrocarbons under mild, solvent-free conditions. In addition, the reported results suggest that activities are not only related to the specific surface area of the catalysts, but that they can also be explained by the type of crystalline structure and surface morphology. Indeed, higher conversions and selectivity (up to 86% and 90%, respectively) were obtained in the oxidation of cyclohexene using TiO2 rutile. Interestingly, these efficient catalytic systems do not require the presence of noble metals to achieve significant activities.
Qadir, Muhammad I.,Scholten, Jackson D.,Dupont, Jairton
p. 225 - 230
(2014/02/14)

Cobalt complex in a room temperature ionic liquid: A convenient recyclable reagent for catalytic epoxidation of cyclic alkenes
Co-catalyzed epoxidation of cyclic alkenes proceeds in ionic liquid media (1-ethyl-3-methylimidazolium hexafluorophosphate). Epoxidation of the alkenes to respective epoxides was greatly accelerated by the use of a cobalt-based catalyst in the presence of H2O2 as an oxidant. The catalyst in ionic liquid [Emim]PF6 was recycled and reused for about seven times.
Ramakrishna, Dileep,Ramachandra Bhat, Badekai,Hanumanthappa, Suresha Kumara T.
p. 1071 - 1074
(2015/02/05)

A comparative study of molybdenum promoted vanadium phosphate catalysts towards epoxidation of cyclohexene
This article describes our efforts in developing molybdenum promoted vanadium phosphate (Mo-VPO) catalyst by two distinct methods and its application in liquid phase oxidation reactions. The materials were characterized by various spectral techniques and their catalytic potential has been investigated for the oxidation of cyclohexene. The influences of various reaction parameters have also been studied. Under optimum reaction conditions excellent to higher yield of epoxide (91%) was obtained by Mo-VPO* prepared by impregnation method. The promoting effect of Mo on VPO solids was found to be a function of the way the ion was added during the preparation of the VOHPO 4·0.5H2O phase. XPS analysis of the catalysts showed the presence of couple V4+/V5+ on the surface of Mo-VPO which facilitates the reaction. The catalyst showed its recapability more than four times without any appreciable change in conversion and selectivity. The synergetic effect between Mo and V, to the contrary, made the active phase, VPO, more stable.
Behera, Gobinda Chandra,Parida
p. 364 - 373
(2013/07/26)

Ring-opening metathesis polymerization with the second generation hoveyda-grubbs catalyst: An efficient approach toward high-purity functionalized macrocyclic oligo(cyclooctene)s
Herein, we present a facile and general strategy to prepare functionalized macrocyclic oligo(cyclooctene)s (cOCOEs) in high purity and high yield by exploiting the ring-opening metathesis polymerization (ROMP) intramolecular backbiting process with the commercially available second generation Hoveyda-Grubbs (HG2) catalyst. In the first instance, ROMP of 5-acetyloxycyclooct-1-ene (ACOE) followed by efficient quenching and removal of the catalyst using an isocyanide derivative afforded macrocyclic oligo(5-acetyloxycyclooct-1-ene) (cOACOE) in high yield (95%), with a weight-average molecular weight (Mw) of 1.6 kDa and polydispersity index (PDI) of 1.6, as determined by gel permeation chromatography (GPC). The structure and purity of the macrocycles were confirmed by NMR spectroscopy and elemental analysis, which indicated the complete absence of end-groups. This was further supported by GPC-matrix assisted laser desorption ionization time-of-flight mass spectroscopy (GPC-MALDI ToF MS), which revealed the exclusive formation of macrocyclic derivatives composed of up to 45 repeat units. Complete removal of residual ruthenium from the macrocycles was confirmed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The same methodology was subsequently extended to the ROMP of 5-bromocyclooct-1-ene and 1,5-cyclooctadiene to prepare their macrocyclic derivatives, which were further derivatized to produce a library of functionalized macrocyclic oligo(cyclooctene)s. A comparative study using the second and third generation Grubbs catalysts in place of the HG2 catalyst for the polymerization of ACOE provided macrocycles contaminated with linear species, thus indicating that the bidendate benzylidene ligand of the Hoveyda-Grubbs catalyst plays an important role in the observed product distributions.
Blencowe, Anton,Qiao, Greg G.
supporting information
p. 5717 - 5725
(2013/05/21)

Force-reactivity property of a single monomer is sufficient to predict the micromechanical behavior of its polymer
We demonstrate an accurate prediction of the micromechanical behavior of a single chain of cyclopropanated polybutadiene, which is governed by rapid isomerization of the cyclopropane moieties at ～1.2 nN, from the force-rate correlation of this reaction measured in a small series of increasingly strained macrocycles. The data demonstrate that a single physical quantity, force, uniquely defines the dynamics across length scales from >100 to 1 nm and that strain imposed through molecular design and that imposed by micromanipulation techniques have equivalent effects on the kinetics of a chemical reaction. This represents a new method of screening potential monomers for applications in stress-responsive materials that could also facilitate atomistic interpretations of single-molecule force experiments.
Akbulatov, Sergey,Tian, Yancong,Boulatov, Roman
supporting information; experimental part
p. 7620 - 7623
(2012/06/30)

Peroxometalates immobilized on magnetically recoverable catalysts for epoxidation
Magnetically separable catalysts were prepared and employed for the epoxidation of olefins with hydrogen peroxide. In all cases the magnetic core was firstly covered with a silica layer to prevent iron ion-initiated decomposition of hydrogen peroxide. The catalytic active species, an ionic liquid-type peroxotungstate, was then immobilized either by hydrogen bonding (catalyst 1) or by covalent SiO linkage (catalyst 2). In addition to a thorough characterization by FT-IR, XRD, NMR, DRIFT, XPS, and TEM, the catalytic potential was evaluated in the epoxidation of a variety of olefins as well as allylic alcohols. Both catalysts showed essentially a constant activity after at least ten consecutive cycles. On the basis of the research above, a new type of magnetically separable catalyst was constructed by immobilization of lacunary-type phosphotungstate by hydrogen bonding between the sulfonate anion and silanol group on the surface of the core-shell magnetic nanoparticles. After the detailed characterization, the catalyst was used in the epoxidation of a variety of olefins and allylic alcohols and was found to possess high activity, selectivity towards epoxides, and a constant activity after at least ten catalytic recycles without solvent.
Qiao, Yunxiang,Li, Huan,Hua, Li,Orzechowski, Lars,Yan, Kai,Feng, Bo,Pan, Zhenyan,Theyssen, Nils,Leitner, Walter,Hou, Zhenshan
p. 1128 - 1138
(2013/03/13)

Guanidinium-based phosphotungstates and ionic liquids as catalysts and solvents for the epoxidation of olefins with hydrogen peroxide
Several penta- and hexaalkylated guanidinium-based ionic liquids (GILs) were tested as solvents for the epoxidation of cyclooctene using the Venturello catalyst, [(C8H17)3N(CH3)] 3[PO4{WO(O2)2}4], and hydrogen peroxide as the oxidant. Epoxide yields were obtained in a broad range between 13 and 79 % depending on both the anion and the substituents on the guanidinium moiety. Recycling experiments showed that the catalyst can be used at least three times. Furthermore, new guanidinium phosphotungstates with the PW12O403- anion were synthesized and characterized. Their catalytic performance was evaluated, and GILs as well as acetonitrile were employed as the solvent. Results were compared to those obtained with the comparable ammonium-based catalysts [NR4] 3[PW12O40] (R = C4H9, C6H13) and the analogous imidazolium-based catalyst [BMIM]3[PW12O40] containing the 1-butyl-3-methylimidazolium cation. Employing different GILs as solvents, similar results were obtained for the guanidinium and imidazolium catalysts but significantly lower epoxide yields were obtained using the ammonium catalysts. On using acetonitrile as the solvent, guanidinium-based catalysts exhibited a better performance than the imidazolium catalyst in the case of linear and branched olefins and vice versa in the case of cyclic olefins. Several guanidinium phosphotungstates and guanidinium-based ionic liquids have been synthesized and characterized. Their catalytic performance in epoxidation reactions with hydrogen peroxide was evaluated and compared to similar ammonium and imidazolium compounds. The reaction systems can be recycled and used in at least three consecutive reactions. Copyright
Gharnati, Loubna,Walter, Olaf,Arnold, Ulrich,Doering, Manfred
experimental part
p. 2756 - 2762
(2011/08/02)

Highly active and green aminopropyl-immobilized phosphotungstic acid on mesocellular silica foam for the O-heterocyclization of cycloocta-1,5-diene with aqueous H2O2
The heteropoly phosphotungstic acid, H3PW12O 40 (HPW), was successfully immobilized on the surface of MCF, SBA-15 and MCM-41 by means of chemical bonding to aminosilane groups. The as-obtained materials were characterized by N2 sorption, TEM, XRD, FT-IR, 13C-, 29Si-, 31P-MAS NMR and XPS. Characterization results suggest that the surface area decreased after grafting amino groups to silica. The as-prepared HPW-NH2-MCF is highly efficient in the O-heterocyclization of cycloocta-1,5-diene (COD) to 2,6-dihydroxy-9-oxabicyclo[3.3.1] nonane (1) and 2-hydroxy-9-oxabicyclo [3.3.1] nonane-6-one (2) with a COD conversion of 100% and (1 + 2) selectivity up to 98%. It is worth mentioning that this material could be reused six times without any significant loss of activity and selectivity. The good stability can be attributed to the strong interaction between the amino groups on the surface of MCF and HPW anions. The Royal Society of Chemistry.
Gao, Ruihua,Zhu, Quanjing,Dai, Wei-Lin,Fan, Kangnian
experimental part
p. 702 - 708
(2011/05/12)

PHARMACEUTICAL COMPOUNDS
Diazapolycyclic compounds having affinity for the opioidergic receptors, preferably for the delta opioidergic receptors, with central and/or peripheral activity, having formula: [in-line-formulae]A1-D1-T1??(I)[/in-line-formulae] wherein: A1 is a group of formula (II): wherein: R1 is phenyl wherein one of the ring hydrogen atoms is substituted with a group selected from C(O)R′, C(O)OR′, C(O)NHR′ or C(O)NR3R4, R′, R3 and R4, being as defined in the application; R2 is phenyl, optionally substituted D1 is a diazapolycyclic group T1 is a group selected from H, alkyl, alkenyl, alkynyl and from the following optionally substituted groups: cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cycloalkylalkyl, heterocycloalkylalkyl, arylalkyl or heteroarylalkyl, and their hydrates and solvates and pharmaceutically acceptable salts.
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Page/Page column 45

(2011/07/06)

Diazacyclic compounds having affinity for opioid receptors
Diazapolycyclic compounds having affinity for the opioidergic receptors, preferably for the delta opioidergic receptors, with central and/or peripheral activity, having formula: ???????? A1-D1-T1?????(I) wherein: - A1 is a group of formula (II): wherein: R1 is phenyl wherein one of the ring hydrogen atoms is substituted with a group selected from C(O)R', C(O)OR', C(O)NHR' or C(O)NR3R4, R', R3 and R4, being as defined in the application; R2 is phenyl, optionally substituted - D1 is a diazapolycyclic group - T1 is a group selected from H, alkyl, alkenyl, alkynyl and from the following optionally substituted groups: cycloalkyl, heterocycloalkyl, aryl, heteroaryl, cycloalkylalkyl, heterocycloalkylalkyl, arylalkyl or heteroarylalkyl, and their hydrates and solvates and pharmaceutically acceptable salts.
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Page/Page column 63

(2011/07/09)

Gels based on cyclic polymers
Cyclic poly(5-hydroxy-1-cyclooctene) (PACOE) was synthesized by ring-expansion metathesis polymerization (REMP), and thiol-ene chemistry was used to cross-link the internal double bonds in the PACOE backbone. This created a novel network material (gels formed from cyclic polymers) with unique structural units, where the cyclic PACOE main chains, which serve as secondary topological cross-linkages, were connected by primary intermolecular chemical cross-linkages. The resulting properties were notably different from those of traditional chemically cross-linked linear PACOE gels, whose gel fraction (GF) and modulus (G) increased while the swelling ratio (Q) decreased with increasing initial polymer concentration in the gel precursor solution (C0). For the gels formed from cyclic polymers, however, the GF, Q, and G all simultaneously increased as C0 increased at the higher range. Furthermore, at the same preparation state (same C0), the swelling ability and the maximum strain at break of the gels formed from cyclic polymers were always greater than those of the gels formed from linear polymers, and these differences became more pronounced as C0 increased.
Zhang, Ke,Lackey, Melissa A.,Cui, Jun,Tew, Gregory N.
supporting information; experimental part
p. 4140 - 4148
(2011/05/07)

Intramolecular bromonium ion assisted epoxide ring-opening: Capture of the oxonium ion with an added external nucleophile
9-Oxabicyclo[6.1.0]non-4-ene (1) undergoes intramolecular bromonium ion-assisted epoxide ring-opening using N-bromosuccinimide via a presumed oxonium ion that is subject to stereospecific, nonregioselective capture with added external nucleophiles produci
Bonney, Karl J.,Braddock, D. Christopher,White, Andrew J. P.,Yaqoob, Muhammad
supporting information; experimental part
p. 97 - 104
(2011/04/12)

Synthesis and biological activity of a novel class nicotinic acetylcholine receptors (nAChRs) ligands structurally related to anatoxin-a
The introduction of the isoxazole ring as bioisosteric replacement of the acetyl group of anatoxin-a led to a new series of derivatives binding to nicotinic acetylcholine receptors. Bulkier substitutions than methyl at the 3 position of isoxazole were shown to be detrimental for the activity. The binding potency of the most interesting compounds with α1, α7 and α3β4 receptor subtypes, was, anyway, only at micromolar level. Moreover, differently from known derivatives with pyridine, isoxazole condensed to azabicyclo ring led to no activity.
Simoni, Daniele,Rondanin, Riccardo,Marchetti, Paolo,Rullo, Cinzia,Baruchello, Riccardo,Grisolia, Giuseppina,Barbato, Giuseppina,Giovannini, Riccardo,Marchioro, Carla,Capelli, Anna Maria,Virginio, Caterina,Bozzoli, Andrea,Borea, Pier Andrea,Merighi, Stefania,Donati, Daniele
scheme or table
p. 5423 - 5427
(2011/10/09)

Synthesis of a molecular charm bracelet via click cyclization and olefin metathesis clipping
We describe the synthesis of a polycatenated cyclic polymer, a structure that resembles a molecular charm bracelet. Ruthenium-catalyzed ring-opening metathesis polymerization of an aminocontaining cyclic olefin monomer in the presence of a chain transfer agent generated an α,ω-diazide functionalized polyamine. Cyclization of the resulting linear polyamine using pseudo-high-dilution coppercatalyzed click cyclization produced a cyclic polymer in 19% yield. The click reaction was then further employed to remove linear contaminants from the cyclic polymer using azide- and alkyne-functionalized scavenging resins, and the purified cyclic polymer product was characterized by gel permeation chromatography, 1H NMR spectroscopy, and IR spectroscopy. Polymer hydrogenation and conversion to the corresponding polyammonium species enabled coordination and interlocking of diolefin polyether fragments around the cyclic polymer backbone using ruthenium-catalyzed ring-closing olefin metathesis to afford a molecular charm bracelet structure. This charm bracelet complex was characterized by 1H NMR spectroscopy, and the catenated nature of the small rings was confirmed using two-dimensional diffusionordered NMR spectroscopy.
Clark, Paul G.,Guidry, Erin N.,Chan, Wing Yan,Steinmetz, Wayne E.,Grubbs, Robert H.
supporting information; experimental part
p. 3405 - 3412
(2010/05/01)

Cyclopropenation of alkylidene carbenes derived from α-silyl ketones
A new cyclopropanation reaction involving Cα-Si bond insertion of alkylidene carbenes derived from α-silyl ketones has been developed. This unprecedented alkylidene carbene reactivity features excellent selectivity for insertion into Cα-Si bonds rather than insertion into Cγ-H bonds or addition to,δ-double or -triple bonds. The selectivity trend clearly indicates that the α-oxygen in the tether significantly promotes Cγ-H insertion, although the Cα-Si bond insertion still competes effectively.
Li, Jingwei,Sun, Chunrui,Lee, Daesung
supporting information; experimental part
p. 6640 - 6641
(2010/07/04)

Novel polyaniline supported cobalt catalyzed aerobic oxidation of unsaturated organic compounds
The oxidation of organic compounds with carbon-carbon double bond with molecular oxygen under atmospheric pressure in the presence of new polyaniline supported catalyst 1 has been studied. This catalyst turned out to be efficient and selective for oxidation of some unsaturated organic compounds. Oxidation of alkenes, cycloalkenes and terpenes give corresponding epoxy derivatives, whereas organic compounds with carbon carbon double bond in benzylic position give ketones as a main product. Taylor & Francis Group, LLC.
Pielichowski, Jan,Kowalski, Grzegorz
experimental part
p. 105 - 111
(2011/08/03)

SOLID PHASE REACTION SYSTEM FOR OXIDATION
A solid phase reaction system for oxidation of an organic compound, having high industrial value in which an organic solvent exerting a reverse influence on earth environments is not necessary, reuse of a catalyst is possible, and high yield can be attained, comprising a mixture of a powdery dispersion medium and a powder of a solid catalyst for the above-described oxidation reaction, and the above-described organic compound and aqueous hydrogen peroxide,wherein the above-described organic compound, the above-described solid catalyst and the above-described aqueous hydrogen peroxide are dispersed in the above-described mixture so that they get into contact mutually.
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(2010/05/13)

Synthesis of amphiphilic polycyclooctene-graft-poly(ethylene glycol) copolymers by ring-opening metathesis polymerization
In this paper, a novel monomer of 4-methyl-3-(carbamate)-carbanilic acid-4-cyclooctene ester (MCCCE) was synthesized and characterized by FTIR, NMR and ESI-MS. Polycyclooctene-graft-blocked isocyanate copolymers were prepared by the copolymerization of MCCCE and cyclooctene via ring-opening metathesis polymerization (ROMP). Amphiphilic polycyclooctene-graft-PEG copolymers were prepared by melt mixing the polycyclooctene-graft-blocked isocyanate copolymers with poly(ethylene glycol) (PEG) at 200 °C. The blocked isocyanate group on MCCCE can be dissociated to produce free isocyanate group, which will react with the end hydroxyl groups on PEG molecules. The effects of monomer-to-catalyst, monomer-to-chain transfer agent ratios on molecular weight of the copolymer were detailedly studied. The water contact angle of polycyclooctene-graft-PEG copolymer is much smaller than that of polycyclooctene.
Shi, Hengchong,Shi, Dean,Yin, Ligang,Luan, Shifang,Zhao, Jie,Yin, Jinghua
scheme or table
p. 449 - 455
(2011/12/15)

Iron-catalyzed epoxidation of aromatic olefins and 1,3-dienes
The combination of iron(III) chloride, pyridine-2,6-dicarboxylic acid and formamidine ligands allows for the epoxidation of styrenes and conjugated dienes in excellent chemoselectivity and yields.
Schroeder, Kristin,Enthaler, Stephan,Join, Benoit,Junge, Kathrin,Beller, Matthias
experimental part
p. 1771 - 1778
(2010/09/11)

Asymmetric meso-epoxide ring-opening with trimethylsilyl cyanide promoted by chiral binuclear complexes of titanium. Dichotomy of C-C versus C-N bond formation
In the presence of chiral catalysts derived from the same chiral hexadentate ligand and aluminium, zinc or titanium ions, the reaction between cyclohexene oxide and trimethylsilyl cyanide can be controlled to give predominantly either the nitrile (up to 99% ee) or the isonitrile product (up to 94% ee). The metal ion, ligand stereochemistry and base concentration all play a role in determining the product ratio.
Belokon, Yuri N.,Chusov, Denis,Peregudov, Alexander S.,Yashkina, Lidia V.,Timofeeva, Galina I.,Maleev, Victor I.,North, Michael,Kagan, Henri B.
experimental part
p. 3157 - 3167
(2010/07/03)

Asymmetric synthesis of (1S,2R)-2-aminocyclooctanecarboxylic acid
A highly efficient asymmetric synthesis of (1S,2R)-2-aminocyclooctanecarboxylic acid has been completed. This asymmetric synthesis using cycloocta-1,5-diene as the starting material is achieved in 77% yield via a four-step sequence from tert-butyl cycloocta-1,7-dienecarboxylate 10 where the extra double bond adjacent to the unsaturated ester is essential to improve the yield. Furthermore, the Michael adduct intermediate (1S,2R,αR)-14 could be used towards the synthesis of the natural product tashiromine.
Garrido, Narciso M.,Blanco, Magda,Cascon, Imanol F.,Diez, David,Vicente, Victor M.,Sanz, Francisca,Urones, Julio G.
experimental part
p. 2895 - 2900
(2009/07/11)

High-activity, single-site mesoporous WO3-MCF materials for the catalytic epoxidation of cycloocta-1,5-diene with aqueous hydrogen peroxide
For the first time, the high-activity, single-site mesoporous WO3-MCF materials were synthesized and characterized by N2 sorption, TEM, UV-vis DRS, UV-Raman, and XPS. It was found that the dispersion and nature of the tungsten species depend strongly on the tungsten oxide content and the support characteristic. The novel catalyst remains a highly ordered mesostructure of the silica support. The catalytic performance of the materials in the epoxidation of cycloocta-1,5-diene with aqueous H2O2 was investigated. The excellent catalytic performance of WO3-MCF in the selective oxidation of cycloocta-1,5-diene was attributed to the presence of isolated tetrahedral {WO4} species and the unique pore structure. The novel catalyst can be easily recycled after reaction and reused many times with no significant loss of activity. The good stability can be attributed to the presence of isolated tungsten species anchored on the support through W{single bond}O{single bond}Si covalent bonds.
Gao, Ruihua,Yang, Xinli,Dai, Wei-Lin,Le, Yingyi,Li, Hexing,Fan, Kangnian
p. 259 - 267
(2008/09/21)