- Ruthenium-catalyzed glycine-selective oxidative backbone modification of peptides
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The reaction of N,C-protected peptides containing glycine residues with peracetic acid in the presence of a ruthenium catalyst gives α-ketoamides derived from the oxidation at the C(α) position of the glycine residues selectively. (C) 2000 Elsevier Science Ltd.
- Murahashi, Shun-Ichi,Mitani, Akira,Kitao, Kyuuhei
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- Oxidative dehydrogenation of ethyl lactate over nanocarbon catalysts: Effect of oxygen functionalities and defects
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Pyruvic acid and pyruvate derivatives are important chemical intermediates which are normally produced using metal-based catalytic materials that could cause serious environmental problems. In the present work, renewable nanocarbon catalysts are applied in this system, and a solvent free and highly selective oxidative dehydrogenation of ethyl lactate (EL) process is achieved to produce ethyl pyruvate (EP) under mild reaction conditions. Chemical titration results provide direct evidence that ketonic carbonyl groups on nanocarbon are active sites for this reaction. Raman, XPS and model catalyst experimental results have shown that there is a dynamic transformation between defects and oxygen functionalities during the catalytic reactions. The reaction pathway is revealed via kinetic analysis, which may shed light on the rational design of carbon catalysts and their potential catalytic applications in the field of fine chemical productions.
- Wang, Dan,Liu, Wei,Xie, Zailai,Tian, Siyuan,Su, Dangsheng,Qi, Wei
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- Highly Selective Oxidation of Ethyl Lactate to Ethyl Pyruvate Catalyzed by Mesoporous Vanadia-Titania
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The direct oxidative dehydrogenation of lactates with molecular oxygen is a "greener" alternative for producing pyruvates. Here we report a one-pot synthesis of mesoporous vanadia-titania (VTN), acting as highly efficient and recyclable catalysts for the conversion of ethyl lactate to ethyl pyruvate. These VTN materials feature high surface areas, large pore volumes, and high densities of isolated vanadium species, which can expose the active sites and facilitate the mass transport. In comparison to homogeneous vanadium complexes and VOx/TiO2 prepared by impregnation, the meso-VTN catalysts showed superior activity, selectivity, and stability in the aerobic oxidation of ethyl lactate to ethyl pyruvate. We also studied the effect of various vanadium precursors, which revealed that the vanadium-induced phase transition of meso-VTN from anatase to rutile depends strongly on the vanadium precursor. NH4VO3 was found to be the optimal vanadium precursor, forming more monomeric vanadium species. V4+ as the major valence state was incorporated into the lattice of the NH4VO3-derived VTN material, yielding more V4+-O-Ti bonds in the anatase-dominant structure. In situ DRIFT spectroscopy and density functional theory calculations show that V4+-O-Ti bonds are responsible for the dissociation of ethyl lactate over VTN catalysts and for further activation of the deprotonation of β-hydrogen. Molecular oxygen can replenish the surface oxygen to regenerate the V4+-O-Ti bonds.
- Zhang, Wei,Innocenti, Giada,Oulego, Paula,Gitis, Vitaly,Wu, Haihong,Ensing, Bernd,Cavani, Fabrizio,Rothenberg, Gadi,Shiju, N. Raveendran
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- Vanadium-based highly active and selective catalysts for oxidative dehydrogenation of ethyl lactate to ethyl pyruvate
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Pyruvates are important intermediates for various bioactive and pharmaceutical molecules. Synthesis of pyruvates is challenging due to low selectivity, as the pyruvates are prone to polymerisation. In the present work, oxidative dehydrogenation of ethyl lactate to ethyl pyruvate was carried out under very mild conditions using vanadium-based homogeneous and heterogeneous catalysts in the presence of aqueous t-butyl hydroperoxide as an oxidant. Homogenous vanadium-based catalyst, VO(acac)2 in acetonitrile solvent, gave excellent conversion (upto 83%) with 100% selectivity to ethyl pyruvate at room temperature. However, the heterogeneous catalyst, V2O5 exhibited very high activity for oxidative dehydrogenation of ethyl lactate only at higher temperature (80 °C). At higher temperature, significant TBHP decomposition was observed if all TBHP was added in one lot. In case of ethyl lactate dehydrogenation using V2O5 catalyst at 80 °C with two equivalents TBHP, 60% ethyl lactate conversion with 100% TBHP conversions were observed after 5 h when all TBHP was added initially in the reaction mixture. However, the ethyl lactate conversion at 80 °C, after 5 h increased to 72% when the same amount of TBHP was added batch wise over a period of 4 h, indicating improved conversion of TBHP to ethyl pyruvate. The heterogeneous catalyst, V2O5 exhibited up to 98% conversion with 100% ethyl pyruvate selectivity at 80 °C after 10 h with 3 equivalent TBHP added batch wise. The homogeneous catalyst could not be reused while V2O5 could be successfully recycled five times without catalytic performances loss. Oxidation proceeds by radical mechanism, as proved by experiment with radical scavenger.
- Doke, Dhananjay S.,Khomane, Sonali B.,Pandhare, Swati L.,Dongare, Mohan K.,Dumeignil, Franck,Umbarkar, Shubhangi B.
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- Selective Aerobic Oxidation of Lactate to Pyruvate Catalyzed by Vanadium-Nitrogen-Doped Carbon Nanosheets
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The catalytic oxidative dehydrogenation of lactates with molecular oxygen is a promising yet challenging route for producing high-value pyruvates from biomass. Here we report a simple synthetic strategy for preparing nitrogen-doped carbon nanosheets (NCNs) starting from two abundant precursors, cheap melamine and glucose, and using a simple thermal-annealing process. The resulting NCNs feature numerous edges and holes for anchoring vanadium oxides (V-NCNs). This creates cooperative catalytic sites that boost the catalytic oxidation of ethyl lactate to ethyl pyruvate. Additionally, we systematically studied the surface nitrogen species of NCNs by varying the pyrolysis temperature, and found that the active pyridinic N-oxide species formed in a high thermal-annealing treatment, acting synergistically with vanadium active sites in converting ethyl lactate with oxygen into ethyl pyruvate under mild conditions.
- Zhang, Wei,Oulego, Paula,Slot, Thierry K.,Rothenberg, Gadi,Shiju, N. Raveendran
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- Vapor-Phase Oxidation of Ethyl Lactate to Pyruvate over Various Oxide Catalysts
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Oxidation of ethyl lactate to pyruvate was carried out in vapor-phase over various oxides.MoO3 showed a higher selectivity than that of the other single oxide examined.Bindary oxides containing molybdenum such as Fe2O3-MoO3 and TeO2-MoO3 showed high selectivities to pyruvate over 90percent at 300 deg C with high lactate conversion over 75percent.The maximum activity on SnO2-MoO3 was observed at a low temperature of 250 deg C.
- Sugiyama, Shigeru,Shigemoto, Naoya,Masaoka, Naoki,Suetoh, Souichi,Kawami, Hideaki,et al.
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- Titania-catalysed oxidative dehydrogenation of ethyl lactate: Effective yet selective free-radical oxidation
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We research here the catalytic oxidative dehydrogenation of ethyl lactate, as an alternative route to ethyl pyruvate. Testing various solid catalysts (Fe2O3, TiO2, V2O 5/MgO-Al2O3, ZrO2, CeO2 and ZnO), we find that simple and inexpensive TiO2 efficiently catalyses this reaction under mild conditions. Furthermore, molecular oxygen was used as the terminal oxidant. Importantly, this reaction runs well also using inexpensive commercial solvent mixtures. Both the desired reaction and the by-products formation follow a free-radical mechanism. Remarkably, adding activated carbon, a solid radical scavenger, hardly affects the catalytic activity, but enhances the product selectivity. This is because this solid radical scavenger hampers the formation of undesired products in solution, without suppressing the oxidation at the catalyst surface. This journal is the Partner Organisations 2014.
- Ramos-Fernandez, Enrique V.,Geels, Norbert J.,Shiju, N. Raveendran,Rothenberg, Gadi
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- Redox-Active Zeolitic Transition Metal Oxides Based on ?μ -Keggin Units for Selective Oxidation
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The design and development of zeolitic transition metal oxides for selective oxidation are interesting due to the combination of the redox properties and microporosities. Redox-active zeolitic transition metal oxides based on ?μ -Keggin iron molybdates were synthesized. O2 can be activated by the materials via an electron-transfer-based process, and the materials can be oxidized even at room temperature. The materials are oxidized and reduced reversibly while the crystal structures are maintained. V is uniformly incorporated in the materials without changing the basic structures, and the redox properties of the materials are tuned by V. The materials are used as robust catalysts for ethyl lactate oxidation to form ethyl pyruvate using O2 as an oxidant.
- Zhang, Zhenxin,Ishikawa, Satoshi,Zhu, Qianqian,Murayama, Toru,Sadakane, Masahiro,Hara, Michikazu,Ueda, Wataru
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- Designing effective solid catalysts for biomass conversion: Aerobic oxidation of ethyl lactate to ethyl pyruvate
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The direct oxidative dehydrogenation of lactates with molecular oxygen is a promising route for producing bio-based pyruvates. But practical implementation of this route means high yields and mild conditions, which in turn require expensive noble-metal ca
- Zhang, Wei,Ensing, Bernd,Rothenberg, Gadi,Raveendran Shiju
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- Design of a folded, conformationally stable oxaloacetate decarboxylase
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Oxaldie-4, a 31-residue polypeptide designed to catalyse the decarboxylation of oxaloacetate, has been synthesised and its structural and catalytic properties characterised. The solution structure of Oxaldie-4 was studied by CD and NMR spectroscopy. Oxaldie-4, the design of which was based on bovine pancreatic polypeptide, adopted a stably folded structure in solution, which was characterised by the tight packing of a poly-proline-like helix and an α-helix as shown by a large number of inter-helix NOEs. The structure of Oxaldie-4 was in sharp contrast to the molten globule-like structure formed by Oxaldie-3, which was based on avian pancreatic polypeptide. The stability of Oxaldie-4 with respect to thermal and urea denaturation was significantly improved when compared to Oxaldie-3. Oxaldie-4 catalysed the decarboxylation of oxaloacetate with Michaelis-Menten saturation kinetics. The kinetic parameters, which were independent of the concentration of the catalyst over the whole range studied, were determined in a spectrophotometric assay at pH 7 and 298 K to be 0.229 s-1, 64.8 mM, and 2.9 M-1 s-1 for kcat, KM, and kcat/KM, respectively. This catalytic efficiency corresponds to a rate increase of almost four orders of magnitude when compared to simple amines such as butylamine. However, despite the stable three-dimensional structure, the catalytic efficiency of Oxaldie-4 was only slightly improved relative to Oxaldie-3, most likely the consequence of the high flexibility of the lysine side chains, which make up the active site of Oxaldie-4.
- Taylor, Susan E.,Rutherford, Trevor J.,Allemann, Rudolf K.
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- Na-doped OMS-2-catalzyed highly selective aerobic oxidation of ethyl lactate to ethyl pyruvate under mild conditions
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The direct oxidation of lactate to pyruvate is an important process for catalytic conversion of biomass, although low selectivity and harsh reaction conditions limit its potential for industrial application. In this study, catalytic oxidation of ethyl lactate (EL) to ethyl pyruvate (EP) over OMS-2-based materials was conducted using O2 as the green oxidant. A 78 % EL conversion and 95 % EP selectivity were obtained in CH3NO2 at 50 °C over a Na-doped OMS-2 catalyst. The conversion and selectivity of the reaction were affected by the dopant loading of catalyst and reaction temperature. Kinetic study found that original OMS-2 showed slightly higher initial reaction rate than modified OMS-2, and the latter gave higher EP yield due to its more labile lattice oxygen. Characterization of the catalyst indicates that the enhancement of surface oxygen vacancies and reducibility from the Na-doping might contribute to the superior catalytic activity.
- Tao, Luyao,Bi, Xiuru,Zhang, Liping,Chen, Gexin,Zhao, Peiqing,Yang, Jun-Li,Meng, Xu
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- Method for preparing alpha-oxocarboxylate through selective oxidation of alpha-hydroxy carboxylate
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The invention discloses a method for preparing alpha-oxocarboxylate through selective oxidation of alpha-hydroxy carboxylate, and relates to the field of preparation of alpha-oxocarboxylate, in a liquid phase solvent, molecular oxygen is used as an oxygen source, vanadium phosphorus oxide (VPO) compounded by + 4 valence V and + 5 valence V is used as a catalyst, and alpha-hydroxy carboxylate is reacted with molecular oxygen to be selectively oxidized to prepare alpha-oxocarboxylate; wherein the vanadium phosphorus oxide (VPO) catalyst is a vanadium phosphorus oxide (VPO) catalyst compounded byvanadyl phosphate (VOPO4) (VV) and vanadyl pyrophosphate ((VO) 2P2O7) (VIV). The vanadium phosphorus oxide (VPO) catalyst is a cheap non-noble metal catalyst and is relatively low in cost; the reaction can be carried out under normal pressure, and the requirement on equipment is low; according to the invention, high yield (90%) of alpha-oxocarboxylate is realized; and the catalyst can be repeatedly used after being reactivated.
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Paragraph 0023; 0027-0028; 0031; 0035-0036; 0047; 0051-0052
(2021/03/13)
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- Oxidative dehydrogenation of ethyl lactate to ethyl pyruvate over vanadium and iron antimonates catalysts
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The oxidative dehydrogenation of ethyl lactate to ethyl pyruvate, corresponding to the first step of a new process in the industrial production of methionine, has been investigated. Iron and vanadium antimonates were developed as catalysts, and were optimized to reach 87 % conversion of ethyl lactate, with 88 % selectivity to ethyl pyruvate, at only 275 °C. The catalysts were characterized before and after catalytic testing, and in situ using various techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and XANES spectroscopy. The results show that neither the Sb3+/Sb5+ nor the Fe2+/Fe3+ redox couple were involved in the dehydrogenation of ethyl lactate, or in the catalysts re-oxidation. The active and selective catalytic sites correspond to surface V5+ species. These species should not be considered as part of the bulk oxide, but as supra-surface species whose surface content is monitored with the bulk composition.
- Huchede,Morvan,Vera,Bellière-Baca,Millet
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- Bismuth subnitrate-catalyzed markovnikov-type alkyne hydrations under batch and continuous flow conditions
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Bismuth subnitrate is reported herein as a simple and efficient catalyst for the atom-economical synthesis of methyl ketones via Markovnikov-type alkyne hydration. Besides an effective batch process under reasonably mild conditions, a chemically intensified continuous flow protocol was also developed in a packed-bed system. The applicability of the methodologies was demonstrated through hydration of a diverse set of terminal acetylenes. By simply switching the reaction medium from methanol to methanol-d4, valuable trideuteromethyl ketones were also prepared. Due to the ready availability and nontoxicity of the heterogeneous catalyst, which eliminated the need for any special additives and/or harmful reagents, the presented processes display significant advances in terms of practicality and sustainability.
- ?tv?s, Sándor B.,Fül?p, Ferenc,Szécsényi, Zsanett
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- Metal-Free Synthesis of Polysubstituted Imidazolinone Through Cyclization of Amidines with 2-Substituted Acrylates
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Polysubstituted imidazolinones were synthesized in a facile metal-free cascade nucleophilic cyclization of easily available amidines and 2-substituted acrylates. This protocol is distinguished by simple, mild, and catalyst-free reaction conditions with a broad substrate scope, affording the desired products in moderate to good yields and providing an efficient strategy for synthesis of polysubstituted imidazolinone.
- Liu, Zhen,Zhang, Yan-Shun,Wei, Yin,Shi, Min
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supporting information
p. 1093 - 1099
(2020/02/27)
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- Self-Exfoliated Synthesis of Transition Metal Phosphate Nanolayers for Selective Aerobic Oxidation of Ethyl Lactate to Ethyl Pyruvate
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Two-dimensional (2D) transition metal nanosheets are promising catalysts because of the enhanced exposure of the active species compared to their 3D counterparts. Here, we report a simple, scalable, and reproducible strategy to prepare 2D phosphate nanosheets by forming a layered structure in situ from phytic acid (PTA) and transition metal precursors. Controlled combustion of the organic groups of PTA results in interlayer carbon, which keeps the layers apart during the formation of phosphate, and the removal of this carbon results in ultrathin nanosheets with controllable layers. Applying this concept to vanadyl phosphate synthesis, we show that the method yields 2D ultrathin nanosheets of the orthorhombic β-form, exposing abundant V4+/V5+ redox sites and oxygen vacancies. We demonstrate the high catalytic activity of this material in the vapor-phase aerobic oxidation of ethyl lactate to ethyl pyruvate. Importantly, these β-VOPO4 compounds do not get hydrated, thereby reducing the competing hydrolysis reaction by water byproducts. The result has superior selectivity to ethyl pyruvate compared to analogous vanadyl phosphates. The catalysts are highly stable, maintaining a steady-state conversion of ～90% (with >80% selectivity) for at least 80 h on stream. This "self-exfoliated" synthesis protocol opens opportunities for preparing structurally diverse metal phosphates for catalysis and other applications.
- Li, Lain-Jong,Oulego, Paula,Rothenberg, Gadi,Sharma, Sandeep K.,Shiju, N. Raveendran,Yang, Xiu-Lin,Zhang, Wei
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p. 3958 - 3967
(2020/05/05)
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- Screening of catalysts for the oxidative dehydrogenation of ethyl lactate to ethyl pyruvate, and optimization of the best catalysts
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This study reports on a new industrial gas-phase process to produce ethyl pyruvate, using the oxidative dehydrogenation of ethyl lactate. In an initial approach, twenty catalysts were screened under reaction conditions required for industrial applications. When evaluated in terms of their maximum selectivity to ethyl pyruvate and their productivity, the best catalyst was found to be a phosphomolybdic polyoxometalate, with iron counter-cations: FePMo12O40. To improve this catalyst, a study was carried out by including cesium counter-cations. The new catalysts exhibited higher yields because of higher Mo active surface site density related to higher specific surface area and although their intrinsic activity was lower. Their ethyl pyruvate selectivity increased with iron content but never overpass that of FePMo12O40. These results are explained in terms of changes in structure and iron counteraction coordination leading or not to electron exchange between iron and molybdenum and influencing the acidity of the catalyst's surface.
- Huchede,Morvan,Bellière-Baca,Millet
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- Electronic Asymmetry of an Annelated Pyridyl-Mesoionic Carbene Scaffold: Application in Pd(II)-Catalyzed Wacker-Type Oxidation of Olefins
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The two donor modules of an annelated pyridyl-mesoionic carbene ligand (aPmic) have different σ- and π-bonding characteristics leading to its electronic asymmetry. A Pd(II) complex 1 featuring aPmic catalyzes the oxidation of a wide range of terminal olefins to the corresponding methyl ketones in good to excellent yields in acetonitrile. The catalytic reaction is proposed to proceed via syn-peroxypalladation and a subsequent rate-limiting 1,2-hydride shift, which is supported by kinetic studies. The electronic asymmetry of aPmic renders a well-defined coordination sphere at Pd. The favored arrangement of reactants on the metal center features an olefin trans to the pyridyl module and a tbutylperoxide trans to the carbene. This arrangement gains added stability by the π-delocalization paved by the compatible orbitals on Pd, the pyridyl module, and the olefin that is perpendicular to the Pd(aPmic) plane. The π-interactions are absent in an alternate arrangement wherein the olefin is trans to the carbene. Density functional theory studies reveal the matching orbital overlaps responsible for the preferred arrangement over the other. This work provides an orbital description for the electronic asymmetry of aPmic.
- Bera, Jitendra K.,Dutta, Indranil,Kunnikuruvan, Sooraj,Reshi, Noor U Din,Saha, Sayantani,Yadav, Suman
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p. 11385 - 11393
(2020/11/23)
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- Chemo- And diastereoselective synthesis of pyrrolidines from aroylformates and δ-tosylamino enones via P(NMe2)3-mediated reductive amination/base-catalyzed michael addition cascade
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A novel P(NMe2)3-mediated tandem (1 + 4) annulation between aroylformates and δ-tosylamino enones has been developed that affords a facile synthesis of functionalized pyrrolidines in moderate to excellent yields with exclusive chemoselectivity and high diastereoselectivity. Mechanistic investigation reveals that the reaction proceeds through an unprecedented P(NMe2)3-mediated reductive amination/base-catalyzed Michael addition cascade. The reaction herein also represents the first study of the reactivity patterns of the Kukhtin-Ramirez adducts toward ambiphilic nucleophile-electrophiles.
- Liu, Rongfang,Liu, Jialin,Cao, Jilei,Li, Ruifeng,Zhou, Rong,Qiao, Yan,Gao, Wen-Chao
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supporting information
p. 6922 - 6926
(2020/09/15)
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- Synthesis of Dihydro-2-oxopyrrole (DPO) Building Blocks Catalyzed by Potassium Carbonate
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A dimerization and cyclization cascade reaction of 2-sulfonaminoacrylates catalyzed by K2CO3 provides dihydro-2-oxopyrrole (DPO) derivatives. This straightforward and atom-economic transformation features a simple experimental operation with easily available starting materials, a broad substrate scope as well as good functional group tolerance. The desired DPO building blocks are obtained in moderate to good yields.
- Zhang, Yan-Shun,Gui, Hou-Ze,Wei, Yin,Shi, Min
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supporting information
p. 7179 - 7185
(2019/11/16)
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- Copper(I)- and Mesoionic-Hydroxyamide-Catalyzed Chemoselective Aerobic Oxidation of Primary Benzylic Alcohols
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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
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p. 315 - 318
(2019/02/12)
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- Novel effect of zinc nitrate/vanadyl oxalate for selective catalytic oxidation of α-hydroxy esters to α-keto esters with molecular oxygen: An in situ ATR-IR study
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Selective oxidation of α-hydroxy esters is one of the most important methods to prepare high value-added α-keto esters. An efficient catalytic system consisting of Zn(NO3)2/VOC2O4 is reported for catalytic oxidation of α-hydroxy esters with molecular oxygen. Up to 99% conversion of methyl DL-mandelate or methyl lactate could be facilely obtained with high selectivity for its corresponding α-keto ester under mild reaction conditions. Zn(NO3)2 exhibited higher catalytic activity in combination with VOC2O4 compared with Fe(NO3)3 and different nitric oxidative gases were detected by situ attenuated total reflection infrared (ATR-IR) spectroscopy. UV-vis and ATR-IR results indicated that coordination complex formed in Zn(NO3)2 in CH3CN solution was quite different from Fe(NO3)3; it is proposed that the charge-transfer from Zn2+ to coordinated nitrate groups might account for the generation of different nitric oxidative gases. The XPS result indicate that nitric oxidative gas derived from the interaction of Zn(NO3)2 with VOC2O4 could be in favor of oxidizing VOC2O4 to generate active vanadium (V) species. It might account for different catalytic activity of Zn(NO3)2 or Fe(NO3)3 combined with VOC2O4. This work contributes to further development of efficient aerobic oxidation under mild reaction conditions.
- Ju, Yongwei,Du, Zhongtian,Xiao, Chuhong,Li, Xingfei,Li, Shuang
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supporting information
(2019/04/05)
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- Asymmetric Counter-Anion-Directed Aminomethylation: Synthesis of Chiral β-Amino Acids via Trapping of an Enol Intermediate
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A novel enantioselective aminomethylation reaction of diazo compound, alcohol and α-aminomethyl ether enabled by asymmetric counteranion-directed catalysis is disclosed that offers an efficient and convenient access to furnish optically active α-hydroxyl-β-amino acids in high yield with high to excellent enantioselectivities. Control experiments and DFT calculations indicate that the transformation proceeds through trapping the in situ generated enol intermediate with methylene iminium ion, and the asymmetric induction was enabled by chiral pentacarboxycyclopentadiene anion via H-bonding and electrostatic interaction.
- Kang, Zhenghui,Wang, Yongheng,Zhang, Dan,Wu, Ruibo,Xu, Xinfang,Hu, Wenhao
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supporting information
p. 1473 - 1478
(2019/01/26)
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- Synthesis method for organically synthesizing intermediate ethyl pyruvate
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The invention discloses a synthesis method for organically synthesizing an intermediate ethyl pyruvate. According to the synthesis method disclosed by the invention, pyruvic acid, ethanol, concentrated sulfuric acid, MoO3, biphenylamine, anhydrous THF (Tetrahydrofuran), trihydroxybenzenetricarboxaldehyde, n-butyl alcohol and o-dichlorobenzene are used as main raw materials, and an MoO3@COF nano-catalyst participates in acid and alcohol heating and refluxing reaction; under the action of the catalyst, carboxylic acid on the pyruvic acid is subjected to carbonyl protonation, so that the eletrophilicity of carbonyl carbon is enhanced and a reaction speed is improved; byproduct water of the reaction can be also removed through water absorptivity of the concentrated sulfuric acid and the yieldof ester is improved; the intermediate catalyst used by the synthesis method overcomes the disadvantages of traditional pyruvic acid esterification reaction that the yield is low, the speed rate is slow, the separation is complicated and the like, and has an excellent catalysis effect on synthesis reaction for organically synthesizing the intermediate ethyl pyruvate.
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Paragraph 0008
(2018/09/13)
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- Diastereo- and Enantioselective Synthesis of Fluorine Motifs with Two Contiguous Stereogenic Centers
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The synthesis of chiral fluorine containing motifs, in particular, chiral fluorine molecules with two contiguous stereogenic centers, has attracted much interest in research due to the limited number of methods available for their preparation. Herein, we report an atom-economical and highly stereoselective synthesis of chiral fluorine molecules with two contiguous stereogenic centers via azabicyclo iridium-oxazoline-phosphine-catalyzed hydrogenation of readily available vinyl fluorides. Various aromatic, aliphatic, and heterocyclic systems with a variety of functional groups were found to be compatible with the reaction and provide the highly desirable product as single diastereomers with excellent enantioselectivities.
- Ponra, Sudipta,Rabten, Wangchuk,Yang, Jianping,Wu, Haibo,Kerdphon, Sutthichat,Andersson, Pher G.
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supporting information
p. 13878 - 13883
(2018/10/24)
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- Highly Efficient Oxidation of Ethyl Lactate to Ethyl Pyruvate Catalyzed by TS-1 under Mild Conditions
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Highly efficient oxidation of ethyl lactate (ELA) to ethyl pyruvate (EP) was realized over TS-1 in the presence of aqueous H2O2 (30 wt %) at low temperature without other solvent. A 100% ELA conversion and 97.8% EP yield were obtained at 50 °C after 9 h. The conversion rate of ELA is sensitive to the reaction temperature. High reaction temperature (70 °C) leads to an increase in conversion rate of ELA but causes the fast hydrolysis and decarboxylation of EP to form byproducts of acetic acid and CO2. On the basis of the characterization (pyridine-FTIR and UV-vis) and reaction results, active species of Ti(OOH) were proven. In addition, a nonradical mechanism for conversion of ELA to EP for this catalytic system was proposed. By kinetic analysis, the formation of Ti(OOH) is confirmed as the rate-determining step. The apparent activation energy (103.4 kJ mol-1) was also obtained. Furthermore, TS-1 was highly stable for the oxidation of ethyl lactate. There were almost no change in ELA conversion and EP yield throughout 10 reaction runs.
- Lu, Tianliang,Zou, Junpeng,Zhan, Yuzhong,Yang, Xiaomei,Wen, Yiqiang,Wang, Xiangyu,Zhou, Lipeng,Xu, Jie
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p. 1287 - 1296
(2018/02/14)
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- Green synthesizing process for pyruvate
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The invention provides a green synthesizing process for pyruvate. Multi-phase catalysis reaction is adopted, a catalyst can be recycled, moreover, catalysis reaction does not need a solvent, reactionconditions are mild, produced wastes are less, and energy conservation and environmental protection are achieved.
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Paragraph 0022-0027; 0034-0037
(2018/04/27)
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- Method for preparing pyruvate through liquid-phase catalytic oxidation of lactate
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The invention provides a method for preparing pyruvate through liquid-phase catalytic oxidation of lactate. The method comprises the following steps: mixing the lactate, a compound catalyst, an oxidant and a reaction solvent and putting a mixture into a reaction container; after mounting the reaction container, starting cooling water and condensing and refluxing, wherein the compound catalyst comprises metal halide and a solid acid catalyst; stirring and raising the temperature to reaction temperature; reacting for certain time at constant temperature; decompressing and distilling to remove the reaction solvent; washing with water to remove an inorganic catalyst; extracting a product by utilizing dichloromethane; decompressing and distilling to remove the dichloromethane to obtain a product, i.e., the lactate. Compared with synthesis methods including a tartrate hydrolysis method, a pyruvate esterification method and the like, the method has the advantages of few reaction steps, moderate reaction conditions, green and environment-friendly reaction process, cheap and efficient catalyst and relatively high conversion rate of raw materials and product selectivity; the method has a relatively good application prospect and relatively high practical value.
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Paragraph 0072-0076; 0079; 0080
(2018/12/13)
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- Understanding the oxidative dehydrogenation of ethyl lactate to ethyl pyruvate over vanadia/titania
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We studied the vapour-phase oxidative dehydrogenation (ODH) of ethyl lactate with air to give ethyl pyruvate over V2O5/TiO2 catalysts in a fixed-bed reactor. The nature of the vanadia species is changed by varying the vanadium surface density, and the corresponding structure of the VOx species was determined by XRD, UV-vis spectroscopy, XPS and H2-TPR. Monomeric and isolated vanadia species dominate at lower vanadium surface densities. As the surface density increases, two-dimensional polyvanadates and bulk-like vanadia crystallites become predominant. The activity per vanadium decreases with increasing vanadium surface density, indicating that the monomeric VOx species is better for pyruvate production and that the V-O-Ti bonds play an important role in the ODH of ethyl lactate. This is also confirmed by the superior catalytic performance of V2O5/TiO2 compared to vanadium supported on MgO, Al2O3, ZrO2 and CeO2. In situ DRIFT spectroscopy coupled with mass analysis shows that the reaction can involve three possible adsorption modes of ethyl lactate on the V2O5/TiO2 surface. Under anaerobic conditions, 2-hydroxypropionate forms, giving ethyl acetate as the major product. Conversely, under aerobic conditions, oxygen that is chemisorbed on V2O5/TiO2 is active and easily replenished from the gas phase, converting the ethyl-propionate-2-oxide intermediate into ethyl pyruvate.
- Zhang, Wei,Innocenti, Giada,Ferbinteanu, Marilena,Ramos-Fernandez, Enrique V.,Sepulveda-Escribano, Antonio,Wu, Haihong,Cavani, Fabrizio,Rothenberg, Gadi,Shiju, N. Raveendran
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p. 3737 - 3747
(2018/08/12)
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- Switchable C-H Functionalization of N-Tosyl Acrylamides with Acryloylsilanes
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A controllable Rh-catalyzed protocol to access alkylation and alkenylation-annulation of N-tosyl acrylamide with acryloyl silane is reported. In contrast to the directing group or catalyst-dependent divergent sp2 C-H alkylation/alkenylation, the intrinsic property of acryloylsilane allows the switchable reaction manifold, thereby affording either alkylation or annulation products with slight modification of the reaction conditions.
- Song, Shengjin,Lu, Ping,Liu, Huan,Cai, Sai-Hu,Feng, Chao,Loh, Teck-Peng
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supporting information
p. 2869 - 2872
(2017/06/13)
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- Selective Carbonyl?C(sp3) Bond Cleavage To Construct Ynamides, Ynoates, and Ynones by Photoredox Catalysis
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Carbon–carbon bond cleavage/functionalization is synthetically valuable, and selective carbonyl?C(sp3) bond cleavage/alkynylation presents a new perspective in constructing ynamides, ynoates, and ynones. Reported here is the first alkoxyl-radical-enabled carbonyl?C(sp3) bond cleavage/alkynylation reaction by photoredox catalysis. The use of novel cyclic iodine(III) reagents are essential for β-carbonyl alkoxyl radical generation from β-carbonyl alcohols, including alcohols with high redox potential (EoxP>2.2 V vs. SCE in MeCN). β-Amide, β-ester, and β-ketone alcohols yield ynamides, ynoates, and ynones, respectively, for the first time, with excellent regio- and chemoselectivity under mild reaction conditions.
- Jia, Kunfang,Pan, Yue,Chen, Yiyun
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supporting information
p. 2478 - 2481
(2017/02/23)
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- A kind of 3,4-dichloro-thiazole derivatives and process for their preparation and use
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The invention provides 3,4-dichloro isothiazole derivatives, their preparation method and application. The invention relates to a heterocyclic compound containing 3,4-dichloro isothiazol, and the compound is represented by the following chemical structural general formula. The invention discloses the structural general formula of the compound, a synthetic method of the compound and applications of the compound as pesticide, bactericide, anti-plant virus agent, and plant activator, and a technology of mixing the compound with agriculturally acceptable auxiliary agents or synergists for preparing pesticide, bactericide, anti-plant virus agent, and plant activator. The invention further discloses the combined application of the compound and the commercial pesticide, bactericide, anti-plant virus agent, and plant activator in controlling diseases, insect pests, and virus diseases in agriculture, forestry and gardening, and a preparation method of the compound and the commercial pesticide, bactericide, anti-plant virus agent, and plant activator.
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Paragraph 0046-0047; 0095-0096
(2016/10/08)
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- OXIDATIVE DEHYDROGENATION OF LACTATE ESTERS TO PYRUVATE ESTERS
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The present invention relates to a simple one step oxidative dehydrogenation process for the synthesis of alkyl pyruvate with 100% selectivity towards alkyl pyruvate comprising reacting an alkyl lactate in the presence of catalyst at the temperature ranging from 25-100°C for the time period ranging from 5 to 40 hours in an organic solvent and hydrogen peroxide to afford alkyl pyruvate.
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Page/Page column 7
(2017/01/31)
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- A catalytic conversion method for preparing pyruvate ester of lactic acid (by machine translation)
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A method for preparing pyruvate through catalytic conversion of lactic acid is provided; according to the method, with oxygen or air as an oxidant, alcohol as a solvent, and molybdovanadophosphoric heteropoly acid and/or tungstovanadophosphoric heteropoly acid as a catalyst, and by coupling of a catalytic oxidation reaction and an esterification reaction, lactic acid is converted into pyruvate by one step. The method directly adopts oxygen or air as the oxidant and is green and safe; the used raw material lactic acid is obtained directly from conversion of biomass resources, moreover, the reaction conditions are mild, and the method has important application prospects.
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Paragraph 0018
(2016/10/10)
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- The method for producing the same and Arylpyruvamide
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PROBLEM TO BE SOLVED: To provide a method for producing pyruvic acid or its ester from lactic acid or its ester under a mild condition by using an inexpensive catalyst. SOLUTION: There is provided the method for producing pyruvic acid or its ester from lactic acid or its ester by reacting lactic acid or its ester in a liquid phase in the presence of a catalyst containing at least vanadium element and an oxidizing agent. The oxidizing agent is preferably molecular oxygen or a peroxide. COPYRIGHT: (C)2011,JPOandINPIT
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Page/Page column 6; 7
(2018/12/12)
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- First Iridium-Catalyzed Highly Enantioselective Hydrogenation of β-Nitroacrylates
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The first highly chemo- and enantioselective hydrogenation of β-nitroacrylates was accomplished with an iridium catalyst (Ir-4) with yields and enantioselectivities of up to 96% and 98% ee, respectively. The resulting α-chiral β-nitro propionates are attractive building blocks for the synthesis of chiral β2-amino acids, which are the core scaffolds of bioactive natural products, pharmaceuticals, and β-peptides.
- Li, Shengkun,Xiao, Taifeng,Li, Dangdang,Zhang, Xumu
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p. 3782 - 3785
(2015/08/18)
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- 4-Benzamido-TEMPO catalyzed oxidation of a broad range of alcohols to the carbonyl compounds with NaBrO3 under mild conditions
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4-Benzamido-TEMPO catalyzed oxidation system for conversion of a wide range of alcohols to the aldehydes or ketones with NaBrO3 under room temperature conditions has been developed. The credible, operationally convenient and economical, and condition mild oxidation protocol is particularly of interest in laboratory and in fine chemicals manufacture. 4-Benzamido-TEMPO catalyzed oxidation system for conversion of a wide range of alcohols to the aldehydes or ketones with NaBrO3 as oxidant under room temperature conditions has been developed. Copyright
- Shen, Jiaxuan,Sun, Jiangkai,Qin, Shuangshuang,Chu, Changhu,Liu, Renhua
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p. 405 - 409
(2014/06/10)
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- METHOD FOR PREPARING PYRUVATE ESTER
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A method for preparing a pyruvate ester is disclosed. In the method of the present invention, a lactate ester is oxidized by hydrogen peroxide in the presence of a Ti-Si molecular sieve catalyst. In the present invention, the Ti-Si molecular sieve catalyst is easily filtered and recycled, the reaction conditions are mild due to the usage of hydrogen peroxide, the process is simple and easily performed, the conversion rate of the lactate ester is high, and the selectivity of the pyruvate ester is high.
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Paragraph 0016
(2014/02/16)
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- Laccase-Mediator System for Alcohol Oxidation to Carbonyls or Carboxylic Acids: Toward a Sustainable Synthesis of Profens
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By combining two green and efficient catalysts, such as the commercially available enzyme laccase from Trametes versicolor and the stable free radical 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO), the oxidation in water of some primary alcohols to the corresponding carboxylic acids or aldehydes and of selected secondary alcohols to ketones can be accomplished. The range of applicability of bio-oxidation is widened by applying the optimized protocol to the oxidation of enantiomerically pure 2-arylpropanols (profenols) into the corresponding 2-arylpropionic acids (profens), in high yields and with complete retention of configuration.
- Galletti, Paola,Pori, Matteo,Funiciello, Federica,Soldati, Roberto,Ballardini, Alberto,Giacomini, Daria
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p. 2684 - 2689
(2016/12/23)
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- Cationic Ir/Me-BIPAM-catalyzed asymmetric intramolecular direct hydroarylation of α-ketoamides
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Asymmetric intramolecular direct hydroarylation of α-ketoamides gives various types of optically active 3-substituted 3-hydroxy-2-oxindoles in high yields with complete regioselectivity and high enantioselectivities (84-98 % ee). This is realized by the use of the cationic iridium complex [Ir(cod) 2](BArF4) and the chiral O-linked bidentate phosphoramidite (R,R)-Me-BIPAM. Carbon's got a brand new bond: Asymmetric intramolecular direct hydroarylation of α-ketoamides gives various optically active 3-substituted 3-hydroxy-2-oxindoles in high yields with complete regioselectivity and high enantioselectivities. This is realized by the use of an asymmetric cationic iridium complex formed in situ (see Scheme).
- Shirai, Tomohiko,Ito, Hajime,Yamamoto, Yasunori
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supporting information
p. 2658 - 2661
(2014/03/21)
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- Efficient aerobic oxidation of secondary alcohols at ambient temperature with an ABNO/NOx catalyst system
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New highly practical methods are presented for aerobic oxidation of secondary alcohols with a nitroxyl radical in combination with HNO3, NaNO2, or both as cocatalysts. Diverse nitroxyls are compared, including several novel bicyclic derivatives. Catalyst systems with the readily available nitroxyls, 9-azabicyclo[3.3.1]nonane-N-oxyl (ABNO) and 9-azabicyclo[3.3.1]nonan-3-one-N-oxyl (keto-ABNO), are optimized in acetic acid or acetonitrile as the solvent. The reactions are compatible with substrates bearing diverse functional groups and proceed efficiently under mild conditions at ambient pressure and temperature.
- Lauber, Markus B.,Stahl, Shannon S.
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p. 2612 - 2616
(2013/11/19)
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- Oxone-mediated oxidative cleavage of β-keto esters and 1,3-diketones to α-keto esters and 1,2-diketones in aqueous medium
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A versatile and highly efficient method for the direct synthesis of α-keto esters and 1,2-diketones has been developed. This approach utilizes the oxidative cleavage of a variety of β-keto esters and 1,3-diketones mediated by an Oxone/aluminum trichloride system. The simple one-step oxidation reaction proceeded selectively in aqueous media to afford products in high yields, short reaction times, and environmentally benign conditions.
- Stergiou, Anastasios,Bariotaki, Anna,Kalaitzakis, Dimitris,Smonou, Ioulia
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p. 7268 - 7273
(2013/08/15)
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- Pyruvamide Compounds as Inhibitors of Dust Mite Group 1 Peptidase Allergen and Their Use
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The present invention pertains generally to the field of therapeutic compounds and more specifically to certain pyruvamide compounds of the formula (X) (for convenience, collectively referred to herein as “PVA compounds”), which, inter alia, inhibit a dust mite Group 1 peptidase allergen (e.g., Der p 1, Der f 1, Eur m 1). The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, to inhibit a dust mite Group 1 peptidase allergen, and in the treatment of diseases and disorders that are mediated by a dust mite Group 1 peptidase allergen; that are ameliorated by the inhibition of a dust mite Group 1 peptidase allergen; asthma; rhinitis; allergic conjunctivitis; atopic dermatitis; an allergic condition which is triggered by dust mites; an allergic condition which is triggered by a dust mite Group 1 peptidase allergen; and canine atopy.
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- Determination of hydride affinities of various aldehydes and ketones in acetonitrile
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Chemical equations presented. The hydride affinities of 21 typical aldehydes and ketones in acetonitrile were determined by using an experimental method, which is valuable for chemists choosing suitable reducing agents to reduce them. The focus of this paper is to introduce a very facile experimental method, which can be used to determine the hydride affinities of various carbonyl compounds in solution.
- Zhu, Xiao-Qing,Chen, Xi,Mei, Lian-Rui
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supporting information; experimental part
p. 2456 - 2459
(2011/07/09)
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- Decarboxylative ketone aldol reactions: Development and mechanistic evaluation under metal-free conditions
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(Chemical Equation Presented) Malonic acid half thioesters (MAHTs) and malonic acid half oxyesters (MAHOs) are shown to undergo decarboxylative nucleophilic addition reactions with ketone and aldehyde electrophiles in the presence of stoichiometric or catalytic quantities of triethylamine at room temperature. The ability to perform these reactions under metal-free conditions has enabled a detailed mechanistic analysis of the reaction pathway leading to the 1H NMR spectroscopic characterization of a postnucleophilic addition/predecarboxylation intermediate and experimental evidence for a reversible formation of this intermediate followed by an irreversible decarboxylation. Rate constants for each of the bond forming/bond breaking steps in the reaction pathway were also determined, casting light on the differing reactivity betweenMAHOandMAHT nucleophiles in these processes. Finally, the mechanistic insights gained through these studies have been employed in the development of a new decarboxylative coumarin synthesis.
- Blaquiere, Nicole,Shore, Daniel G.,Rousseaux, Sophie,Fagnou, Keith
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supporting information; experimental part
p. 6190 - 6198
(2009/12/24)
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- Preparation and Characterization of [5-13C]-(2S,4R)-Leucine and [4-13C]-(2S,3S)-Valine - Establishing Synthetic Schemes to Prepare Any Site-Directed Isotopomer of L-Leucine, L-Isoleucine and L-Valine
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In this paper a chemo-enzymatic method has been developed that gives access to any isotopomer of the essential amino acids isoleucine and valine. The method gives the correct introduction of the second chiral center in (2S,3S)-isoleucine and allows for discrimination between the two prochiral methyl groups in valine as shown by the preparation of (2S,3S)-[4- 13C] valine. For the preparation of (2S)-leucine in any isotopomeric form, the O'Donnell method to prepare optically active amino acids has been used. The protected glycine scaffold used in this method has been prepared by a strategy that allows access to any isotopomeric form. The preparation of [5-13C]-(2S,4R)-leucine shows that the O'Donnell method in combination with the Evans method to obtain chiral 2-methylpropyl iodide leads to a good discrimination between the two prochiral methyl groups. The O'Donnell strategy for the preparation of α-amino acids is preferred over other methods since the reaction conditions are mild, the chiral auxiliary can be easily recovered and the optically active product can be easily separated. For the preparation of isotopically enriched valine and isoleucine the O'Donnell method is not suitable, because the alkyl substituents involved have a secondary halide substituent which is sterically too hindered to give an effective reaction with the protected glycine. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
- Siebum, Arjan H. G.,Woo, Wei Sein,Lugtenburg, Johan
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p. 4664 - 4678
(2007/10/03)
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- Facile Synthesis of α-Ketocarbonyl Compounds from α-Hydroxycarbonyl Compounds
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Various α-ketocarbonyl compounds were obtained in excellent yields under mild condition from the reaction of the corresponding α-hydroxycarbonyl compounds with sodium hypobromite in the presence of HCl catalyst.
- Chang, Hae Sung,Woo, Jae Chun,Lee, Kyoung Mo,Ko, Young Kwan,Moon, Surk-Sik,Kim, Dae-Whang
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- Process for transesterifying α-Ketocarboxylic esters
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Process for transesterifying α-ketocarboxylic esters in an anhydrous alcohol as reaction medium in the presence of tin catalysts, titanium catalysts, zirconium catalysts or lithium catalysts or of acetylacetonates as catalysts.
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- Inversion of enantioselectivity during the platinum-catalyzed hydrogenation of an activated ketone
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Two competing reaction pathways, which lead to opposite enantiomers (see scheme), occur in the hydrogenation of 1 over chirally modified platinum, as revealed by catalytic and NMR spectroscopic experiments: the fast reduction of the ketoform 1a (minor species) and the slow hydrogenolysis of the hydrate 3 (major species).
- Von Arx, Matthias,Mallat, Tamas,Baiker, Alfons
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p. 2302 - 2305
(2007/10/03)
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- Preparation process for alpha , beta -dicarbonylated compounds
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Preparation process for alpha , beta -dicarbonylated compounds of formula (I) in which R2=alkyl, phenyl or benzyl being able to be substituted in various ways on the cycle, or carboxylic ester, and R3=alkyl or alkoxy or carboxylic ester in which a compound of formula (II) in which R1=alkyl, or alkyl alpha -ketocarboxylate or carboxylic ester, and R2 and R3 have the same meanings as previously is reacted in a nitrile type solvent, with molecular oxygen in the presence of copperII nitrate or ferric chloride as catalyst, and use for obtaining ethyl alpha -ketobutyrate, ethyl phenyl pyruvate, ethyl pyruvate, ethyl phenylglyoxylate, butane-2,3-dione or diethyl mesoxalate.
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- Baker's Yeast-Mediated Reductions of α-Keto Esters and an α-Keto-β-Lactam. Two Routes to the Paclitaxel Side Chain
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Baker's yeast (Saccharomyces cerevisiae) has been used to reduce a series of alkyl esters derived from pyruvate and benzoylformate. Both the yield and enantioselectivities of these reductions were maximized when methyl esters were used, and the (R)-alcohols were isolated in all instances. Yeast-mediated ester hydrolysis was a significant side reaction for products derived from long-chain alcohols. In the case of ethyl benzoylformate, the addition of methyl vinyl ketone increased the enantioselectivity of the reduction. These reductions were applied to two syntheses of the paclitaxel C13 side chain [(2R,3S)-N-benzoyl-3-phenylisoserine]. In the first, a racemic α-keto-β-azido ester was reduced by whole cells of Baker's yeast to afford a diastereomeric mixture in which the desired product predominated and could be isolated chromatographically. In the second, an easily synthesized α-keto-β-lactam was reduced by yeast cells to afford the desired eis isomer as well as the undesired trans diastereomer. Substituting a yeast strain deficient in fatty acid synthase in this reduction suppressed formation of the trans diastereomer. These results suggest that a single enzyme is responsible for both the D- and L-cis-alcohols resulting from reduction of the α-keto-β-lactam. All of the yeast strains used in this project are available commercially, and these biocatalytic reductions require only common laboratory equipment.
- Kayser, Margaret M.,Mihovilovic, Marko D.,Kearns, Jeff,Feicht, Anton,Stewart, Jon D.
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p. 6603 - 6608
(2007/10/03)
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