- Byproduct formation during the biosynthesis of spinosyn A and evidence for an enzymatic interplay to prevent its formation
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Biosynthesis of spinosyn A in Saccharopolyspora spinosa involves a 1,4-dehydration followed by an intramolecular [4 + 2]-cycloaddition catalyzed by SpnM and SpnF, respectively. The cycloaddition also takes place in the absence of SpnF leading to questions
- Choi, Sei-hyun,Franklin, Joseph Livy,Huang, Teng-Yi,Hung, Shang-Cheng,Jeon, Byung-sun,Kim, Namho,Liu, Hung-wen,Ruszczycky, Mark W.
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supporting information
(2021/11/30)
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- Acridine Orange Hemi(Zinc Chloride) Salt as a Lewis Acid-Photoredox Hybrid Catalyst for the Generation of α-Carbonyl Radicals
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A readily accessible organic-inorganic hybrid catalyst is reported for the reductive fragmentation of α-halocarbonyl compounds. The robust hybrid catalyst is a self-stabilizing combination of ZnCl2 Lewis acid and acridine orange as the photoactive organic dye. Mechanistic specifics of this hybrid catalyst have been studied in detail using both photophysical and electrochemical experiments. A systematic study enabled the discovery of the appropriate Lewis acid for the effective LUMO stabilization of α-halocarbonyl compounds and thereby lowering of reduction potential within the range of a standard organic dye. This strategy resolves the issues like dehalogenative hydrogenation or homo-coupling of alkyl radicals by guiding the photoredox cycle through an oxidative quenching pathway. The cooperativity between the photoactive organic dye and the Lewis acid counterparts empowers functionalization with a wide range of coupling partners through efficient and controlled generation of alkyl radicals and serves as an appropriate alternative to the expensive late transition metal-based photocatalysts. To demonstrate the application potential of this cooperative catalytic system, four different synthetic transformations of α-carbonyl bromides were explored with broad substrate scopes.
- Das, Sanju,De Sarkar, Suman,Mandal, Tanumoy
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supporting information
(2021/12/10)
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- Investigation of the effect of different linker chemotypes on the inhibition of histone deacetylases (HDACs)
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Histone Deacetylases (HDACs) are among the most attractive and interesting targets in anticancer drug discovery. The clinical relevance of HDAC inhibitors (HDACIs) is testified by four FDA-approved drugs for cancer treatment. However, one of the main drawbacks of these drugs resides in the lack of selectivity against the different HDAC isoforms, resulting in severe side effects. Thus, the identification of selective HDACIs represents an exciting challenge for medicinal chemists. HDACIs are composed of a cap group, a linker region, and a metal-binding group interacting with the catalytic zinc ion. While the cap group has been extensively investigated, less information is available about the effect of the linker on isoform selectivity. To this aim, in this work, we explored novel linker chemotypes to direct isoform selectivity. A small library of 25 hydroxamic acids with hitherto unexplored linker chemotypes was prepared. In vitro tests demonstrated that, depending on the linker type, some candidates selectively inhibit HDAC1 over HDAC6 isoform or vice versa. Docking calculations were performed to rationalize the effect of the novel linker chemotypes on biologic activity. Moreover, four compounds were able to increase the levels of acetylation of histone H3 or tubulin. These compounds were also assayed in breast cancer MCF7 cells to test their antiproliferative effect. Three compounds showed a significant reduction of cancer proliferation, representing valuable starting points for further optimization.
- Linciano, Pasquale,Benedetti, Rosaria,Pinzi, Luca,Russo, Fabiana,Chianese, Ugo,Sorbi, Claudia,Altucci, Lucia,Rastelli, Giulio,Brasili, Livio,Franchini, Silvia
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- (Trifluoromethylselenyl)methylchalcogenyl as Emerging Fluorinated Groups: Synthesis under Photoredox Catalysis and Determination of the Lipophilicity
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The synthesis of molecules bearing (trifluoromethylselenyl)methylchalcogenyl groups is described via an efficient two-step strategy based on a metal-free photoredox catalyzed decarboxylative trifluoromethylselenolation with good yields up to 88 %, which raised to 98 % in flow chemistry conditions. The flow methods allowed also to scale up the reaction. The mechanism of this key reaction was studied. The physicochemical characterization of these emerging groups was performed by determining their Hansch–Leo lipophilicity parameters with high values up to 2.24. This reaction was also extended to perfluoroalkylselenolation with yields up to 95 %. Finally, this method was successfully applied to the functionalization of relevant bioactive molecules such as tocopherol or estrone derivatives.
- Grollier, Kevin,De Zordo-Banliat, Arnaud,Bourdreux, Flavien,Pegot, Bruce,Dagousset, Guillaume,Magnier, Emmanuel,Billard, Thierry
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supporting information
p. 6028 - 6033
(2021/03/15)
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- Synthesis of and characterization of some Heterocyclic Compounds derived from Thiophenol
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This research work involved preparation of heterogeneous pent lateral cyclic compounds (thiazolidine -4- one, benzothiazole, triazole, 4-oxothiazolidin) using thiophenol as raw materials: Thiophenol was reacted with mono chloroacetic acid in the presence of potassium hydroxide to prepare (sh1) followed by ortho amino aniline results the (sh2). The reaction of thiophenol with ethylchloroacetate afforded (sh3) and the reaction of (sh3) with thiosemicarbazide and 4% NaOH leads to ring closure giving 1,2,4- triazole (sh5). A treatment of thiophenol with hydrazine hydrate to obtain the intermediate (sh6) with aromatic aldehyde synthesized azomethines (sh7- sh9) then treated with mercaptoacetic acid to obtained (sh10-sh12). A treatment of thiophenol with chloroacetyl chloride produced (sh13) compound then treated with hydrazine hydrate to obtain (sh14) compound followed by bromobenzaldehyde synthesized azomethine (sh15) compound then treated with mercaptoacetic acid to obtained (sh16) compound. Characterization results for the prepared compounds using IR spectroscopy, NMR and melting points confirmed their chemical structures.
- AL-Khazraji, Shaima Ibraheem Chyad
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p. 5655 - 5662
(2021/09/11)
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- Noncanonical Heme Ligands Steer Carbene Transfer Reactivity in an Artificial Metalloenzyme**
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Changing the primary metal coordination sphere is a powerful strategy for tuning metalloprotein properties. Here we used amber stop codon suppression with engineered pyrrolysyl-tRNA synthetases, including two newly evolved enzymes, to replace the proximal histidine in myoglobin with Nδ-methylhistidine, 5-thiazoylalanine, 4-thiazoylalanine and 3-(3-thienyl)alanine. In addition to tuning the heme redox potential over a >200 mV range, these noncanonical ligands modulate the protein's carbene transfer activity with ethyl diazoacetate. Variants with increased reduction potential proved superior for cyclopropanation and N–H insertion, whereas variants with reduced Eo values gave higher S–H insertion activity. Given the functional importance of histidine in many enzymes, these genetically encoded analogues could be valuable tools for probing mechanism and enabling new chemistries.
- Dunkelmann, Daniel,Hayashi, Takahiro,Hilvert, Donald,Mittl, Peer R. E.,Ota, Yusuke,Pott, Moritz,Tinzl, Matthias
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supporting information
p. 15063 - 15068
(2021/06/09)
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- Air-stable binuclear Titanium(IV) salophen perfluorobutanesulfonate with zinc power catalytic system and its application to C–S and C–Se bond formation
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An air-stable μ-oxo-bridged binuclear Lewis acid of titanium(IV) salophen perfluorobutanesulfonate [{Ti(salophen)H2O}2O][OSO2C4F9]2 (1) was successfully synthesized by the reaction of TiIV(salophen)Cl2 with AgOSO2C4F9 and characterized by techniques such as IR, NMR and HRMS. This complex was stable open to air over a year, and exhibited good thermal stability and high solubility in polar organic solvents. The complex also had relatively strong acidity with a strength of 0.8 Ho ≤ 3.3, and showed high catalytic efficiency towards various C–S and C–Se bond formations in the presence of zinc power. This catalytic system affords a mild and efficient approach to synthesis of thio- and selenoesters, α-arylthio- and seleno-carbonyl compounds, and thio- and selenoethers.
- Wang, Lingxiao,Qiao, Jie,Wei, Jiancong,Liang, Zhiwu,Xu, Xinhua,Li, Ningbo
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- Rhodium-catalyzed Sommelet-Hauser type rearrangement of α-diazoimines: Synthesis of functionalized enamides
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An efficient rhodium catalyzed Sommelet-Hauser type rearrangement of sulfur ylides derived from α-thioesters and N-sulfonyl-1,2,3-triazoles has been successfully accomplished for the synthesis of various functionalized enamides. The developed reaction involves the unprecedented [2,3]-sigmatropic rearrangement of sulfur ylides with the imine motif. Importantly, the method works well with various substituted α-thioesters/-amides/-ketones and substituted N-sulfonyl-1,2,3-triazoles and allows the synthesis of diverse enamide derivatives in good to excellent yields. The reaction was also successfully extended to the one-pot synthesis of enamides from terminal alkynes.
- Anbarasan, Pazhamalai,Ramachandran, Kuppan,Reddy, Angula Chandra Shekar,Reddy, Palagulla Maheswar
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supporting information
p. 5649 - 5652
(2020/06/09)
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- Catalyst-free, visible-light-promoted S-H insertion reaction between thiols and α-diazoesters
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A visible-light-promoted S-H insertion reaction between thiols and α-diazoesters was developed. The reaction proceeded smoothly at room temperature with a broad substrate scope, affording various thioethers in moderate to excellent yields. The catalyst- A
- Chen, Shuwen,Huo, Congde,Liu, Cai,Ma, Ben,Song, Menghui,Wang, Ganggang,Yang, Jingya,Zhou, Hongyan
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supporting information
p. 9494 - 9498
(2020/12/15)
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- Gold-Catalyzed Oxidation of Thioalkynes to Form Phenylthio Ketene Derivatives via a Noncarbene Route
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Gold-catalyzed oxidations of thioalkynes with 8-methylquinoline oxides afford 2-phenylthioketenes that can be trapped efficiently with alcohols. The synthetic utility is manifested by terminal and internal thioalkynes over a wide scope, bearing esters, ke
- Sharma, Pankaj,Singh, Rahulkumar Rajmani,Giri, Sovan Sundar,Chen, Liang-Yu,Cheng, Mu-Jeng,Liu, Rai-Shung
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p. 5475 - 5479
(2019/08/01)
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- Photochemical, Metal-Free Sigmatropic Rearrangement Reactions of Sulfur Ylides
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Sigmatropic rearrangement reactions constitute one of the most fundamental reactions of carbenes. While state-of-the-art synthetic methods require the use of expensive precious metal catalysts, the application of visible light for the photolysis of α-aryldiazoacetates is much less investigated and provides an operationally simple entry to carbenes under mild reaction conditions. Herein, we report on blue-light induced sigmatropic rearrangement reactions of sulfur compounds with α-aryldiazoacetates. This process, depending on the substitution pattern of the sulfide, opens up formal insertion reactions of carbenes into S?N, S?C, or C?H bonds.
- Yang, Zhen,Guo, Yujing,Koenigs, Rene M.
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supporting information
p. 6703 - 6706
(2019/05/10)
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- Rhodium-Catalyzed Rearrangement of S/Se-Ylides for the Synthesis of Substituted Vinylogous Carbonates
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An efficient rhodium-catalyzed unprecedented oxa-[2,3]-sigmatropic rearrangement of sulfur ylide derived from α-thioesters/ketones and diazo carbonyl compounds has been accomplished for the synthesis of various sulfur-tethered vinylogous carbonates in good to excellent yields. Important features of the developed reaction include wide functional group tolerance, excellent chemo- and regioselectivity, and efficient rearrangement involving the carbonyl motif. The present reaction also equally works well with α-selenoesters for the synthesis of seleno-containing vinylogous carbonates.
- Reddy, Angula Chandra Shekar,Anbarasan, Pazhamalai
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supporting information
p. 9965 - 9969
(2019/12/24)
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- Asymmetric Catalytic [2,3] Stevens and Sommelet–Hauser Rearrangements of α-Diazo Pyrazoleamides with Sulfides
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Catalytic enantioselective [2,3] Stevens and Sommelet–Hauser rearrangements of α-diazo pyrazoleamides with sulfides were achieved by utilizing chiral N,N′-dioxide/nickel(II) complex catalysts. These rearrangements proceeded well under mild reac
- Lin, Xiaobin,Yang, Wei,Yang, Wenkun,Liu, Xiaohua,Feng, Xiaoming
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supporting information
p. 13492 - 13498
(2019/08/28)
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- Sulfonium ylide formation and subsequent C[sbnd]S bond cleavage of aromatic isopropyl sulfide catalyzed by hemin in aqueous solvent
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Heme is an abundant and widely existed cofactor for a variety of metalloenzymes, whose broader use is generally impeded by its high instability and poor solubility. Here we report an environment-benign and efficient strategy for the sulfonium ylide formation and subsequent C[sbnd]S bond cleavage of aromatic isopropyl sulfides, which was catalyzed by hemin in assistance of Triton X-100. This aqueous catalytic system exhibited good functional group tolerance to a variety of sulfides and diazo esters. And the reaction mechanism was preliminarily proposed on the basis of designed reactions. Furthermore, the cleavage of C[sbnd]S bond followed by introducing a functional ester group to aromatic sulfides, may potentially be employed for the late stage functionalization (LSF) of organosulfur drug in the future.
- Yan, Xiaojing,Li, Chang,Xu, Xiaofei,He, Quan,Zhao, Xiaoyong,Pan, Yuanjiang
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supporting information
p. 3081 - 3087
(2019/05/08)
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- Dealkylative intercepted rearrangement reactions of sulfur ylides
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Sulfur ylides are well-known to undergo sigmatropic rearrangement reaction. Herein, we describe a novel reactivity of sulfur ylides, which provides access to the product of a formal functional group metathesis upon dealkylative interception of the rearrangement process. Using a simple iron catalyst and in situ generated diazoalkanes this method provides access to α-mercaptoacetonitrile derivatives.
- Empel, Claire,Hock, Katharina J.,Koenigs, Rene M.
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supporting information
p. 338 - 341
(2019/01/09)
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- Preparation method and application of novel ionic binuclear Schiff base titanium complex
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The invention provides a preparation method of a novel ionic binuclear Schiff base titanium complex and a synthetic method of applying the novel ionic binuclear Schiff base titanium complex to catalyze zinc powder and reduce disulfide or selenide to prepare sulfo(seleno) ester and dissymmetric sulfoether(selenide). The complex is a cationic binuclear Schiff base titanium complex, wherein titaniumatoms are bridged by oxygen atoms and are coordinated with a Schiff base ligand and a hydrone, and an ionic bond is formed by a cation part and an anion part of whole Schiff base titanium. The ionic binuclear Schiff base titanium complex is used as a catalyst, the zinc powder is used as a reducer, the disulfide(selenide) can be reduced and fractured, and the disulfide(selenide) can further and respectively react with anhydride, an alpha-bromo carbonyl compound and bromoalkane to prepare the sulfo(seleno) ester and the dissymmetric sulfoether(selenide). According to the preparation method provided by the invention, the defects that traditional lewis acid halide is deliquescent, an absolute solvent is used, conditions are strict and the like are overcome; an effective path for reducing the disulfide or selenide to prepare the sulfo(seleno) ester and the dissymmetric sulfoether(selenide) is provided, and the preparation method has the advantages of high yield, simpleness in operation andthe like.
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-
Paragraph 0065; 0066
(2018/04/03)
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- Synthesis of: N -alkylated 2-pyridones through Pummerer type reactions of activated sulfoxides and 2-fluoropyridine derivatives
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N-Alkylated 2-pyridone products were obtained in good to excellent yields through a one-pot procedure involving either normal or interrupted Pummerer reactions between triflic anhydride activated sulfoxides and 2-fluoropyridine derivatives, followed by hydrolysis. This is a rare case that uses 2-fluoropyridine as a nucleophile in Pummerer type reactions.
- Hu, Gang,Xu, Jiaxi,Li, Pingfan
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p. 4151 - 4158
(2018/06/12)
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- Identification, structure modification, and characterization of potential small-molecule SGK3 inhibitors with novel scaffolds
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The serum and glucocorticoid-regulated kinase (SGK) family has been implicated in the regulation of many cellular processes downstream of the PI3K pathway. It plays a crucial role in PI3K-mediated tumorigenesis, making it a potential therapeutic target for cancer. SGK family consists of three isoforms (SGK1, SGK2, and SGK3), which have high sequence homology in the kinase domain and similar substrate specificity with the AKT family. In order to identify novel compounds capable of inhibiting SGK3 activity, a high-throughput screening campaign against 50,400 small molecules was conducted using a fluorescence-based kinase assay that has a Z' factor above 0.5. It identified 15 hits (including nitrogen-containing aromatic, flavone, hydrazone, and naphthalene derivatives) with IC50 values in the low micromolar to sub-micromolar range. Four compounds with a similar scaffold (i.e., a hydrazone core) were selected for structural modification and 18 derivatives were synthesized. Molecular modeling was then used to investigate the structure-activity relationship (SAR) and potential protein–ligand interactions. As a result, a series of SGK inhibitors that are active against both SGK1 and SGK3 were developed and important functional groups that control their inhibitory activity identified.
- Gong, Grace Qun,Wang, Ke,Dai, Xin-Chuan,Zhou, Yan,Basnet, Rajesh,Chen, Yi,Yang, De-Hua,Lee, Woo-Jeong,Buchanan, Christina Maree,Flanagan, Jack Urquhart,Shepherd, Peter Robin,Chen, Ying,Wang, Ming-Wei
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p. 1902 - 1912
(2018/07/31)
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- Synthesis of a new series of Ni(II), Cu(II), Co(II) and Pd(II) complexes with an ONS donor Schiff base: Crystal structure, DFT study and catalytic investigation of palladium and nickel complexes towards deacylative sulfenylation of active methylenes and regioselective 3-sulfenylation of indoles: Via thiouronium salt formation
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A series of Ni(ii), Cu(ii), Co(ii), and Pd(ii) complexes have been synthesized with a chelating Schiff base ligand coordinated to a metal center with ONS donor atoms. The ligand and complexes are characterized by elemental analysis and spectroscopic techniques like FT-IR, 1H-NMR, and UV-Visible spectroscopy. The single crystal structure of the Pd(ii) complex is obtained by X-ray diffraction analysis and exhibits slightly distorted square planar geometry. The structure is optimized by DFT, TD-DFT calculation to elaborate the electronic structure and NBO for the charge distribution analysis of the Pd(ii) complex. The synthesized Pd(ii) and Ni(ii) complexes as catalysts have been investigated in the C-S cross-coupling of indoles and active methylenes. The metal propelled regioselective transformation afforded 3-sulfenylated indoles while β-diketones favored deacylated monosulfenyl ketones in an excellent yield via thiouronium salt formation. The Pd(ii) complex displays slightly better reactivity whereas the Ni(ii) complex is cost-efficient. The method is fast, easy to handle and cost effective in terms of high reactivity of catalysts, use of non-toxic solvents, and cheaper aryl halides and thiourea replace conventional sulfur sources, providing a practical access to organic transformations.
- Devi, Namita,Sarma, Kuladip,Rahaman, Rajjakfur,Barman, Pranjit
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p. 4583 - 4595
(2018/04/03)
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- Metal Substitution Modulates the Reactivity and Extends the Reaction Scope of Myoglobin Carbene Transfer Catalysts
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Engineered myoglobins have recently emerged as promising scaffolds for catalyzing carbene-mediated transformations. In this work, we investigated the effect of altering the metal center and first-sphere coordination residue on the carbene transfer reactivity of myoglobin. To this end, we first established an efficient protocol for the recombinant expression of myoglobin variants incorporating metalloporphyrins with non-native metals, including second- and third-row transition metals (ruthenium, rhodium, iridium). Characterization of the cofactor-substituted myoglobin variants across three different carbene transfer reactions (cyclopropanation, N–H insertion, S–H insertion) revealed a major influence of the nature of the metal center, its oxidation state and first-sphere coordination environment on the catalytic activity, stereoselectivity, and/or oxygen tolerance of these artificial metalloenzymes. In addition, myoglobin variants incorporating manganese- or cobalt-porphyrins were found capable of catalyzing an intermolecular carbene C–H insertion reaction involving phthalan and ethyl α-diazoacetate, a reaction not supported by iron-based myoglobins and previously accessed only using iridium-based (bio)catalysts. These studies demonstrate how modification of the metalloporphyrin cofactor environment provides a viable and promising strategy to enhance the catalytic properties and extend the reaction scope of myoglobin-based carbene transfer catalysts. (Figure presented.).
- Sreenilayam, Gopeekrishnan,Moore, Eric J.,Steck, Viktoria,Fasan, Rudi
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supporting information
p. 2076 - 2089
(2017/06/23)
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- Scope and Mechanism of Iridium Porphyrin-Catalyzed S-H Insertion Reactions between Thiols and Diazo Esters
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The insertion of carbenes derived from ethyl diazoacetate (EDA), methyl diazoacetate (MDA), methyl phenyldiazoacetate (MPDA), and methyl (p-tolyl)diazoacetate (MTDA) into the S-H bonds of aromatic and aliphatic thiols was catalyzed by (5,10,15,20-tetratolylporphyrinato)methyliridium(III), Ir(TTP)CH3, at ambient temperatures. Yields of the resulting thioether products were as high as 97% for aromatic thiols, with catalyst loadings as low as 0.07 mol %. Thiol binding to Ir(TTP)CH3 was measured at 23 °C by titration studies, providing equilibrium constants, Kb, ranging from 4.25 × 102 to 1.69 × 103 and increasing in the order p-nitrobenzenethiol a mechanism that involves a rate-limiting nucleophilic attack of thiols on an iridium-carbene species, where the major species present in the reaction solution is an inactive, hexacoordinate Ir-thiol complex.
- Dairo, Taiwo O.,Woo, L. Keith
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p. 927 - 934
(2017/04/21)
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- MYOGLOBIN-BASED CATALYSTS FOR CARBENE TRANSFER REACTIONS
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Methods are provided for carrying out carbene transfer transformations such as olefin cyclopropanation reactions, carbene heteroatom-H insertion reactions (heteroatom = N, S, Si), sigmatropic rearrangement reactions, and aldehyde olefination reactions with high efficiency and selectivity by using a novel class of myoglobin-based biocatalysts. These methods are useful for the synthesis of a variety of organic compounds which contain one or more new carbon-carbon or carbon-heteroatom (N, S, or Si) bond. The methods can be applied for conducting these transformations in vitro (i.e., using the biocatalyst in isolated form) and in vivo (i.e., using the biocatalyst in a whole cell system).
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Paragraph 0077; 00297; 00298
(2016/06/14)
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- Fe-Mediated S-S Bond Cleavage and Its Application in the Synthesis of α-Arylthio Carbonyl Compounds
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In the presence of iron dust, diaryl disulfides react with α-bromo carbonyl compounds to obtain α-arylthio carbonyl compounds in good yield at 90 °C under an N2 atmosphere, using commercial dimethylformamide (DMF) as solvent. The possible reaction mechanism is that the disulfide is reduced by iron dust to give ArSFeSAr and then reacted with α-bromo carbonyl compounds to give product α-arylthio carbonyl compounds and FeBr2.
- He, Yun-Hua,Li, Ning-Bo,Chen, Jin-Yang,Qiu, Ren-Hua,Wang, Xie,Xu, Xin-Hua
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p. 1817 - 1822
(2015/08/06)
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- Intermolecular carbene S-H insertion catalysed by engineered myoglobin-based catalysts
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The first example of a biocatalytic strategy for the synthesis of thioethers via an intermolecular carbene S-H insertion reaction is reported. Engineered variants of sperm whale myoglobin were found to efficiently catalyze this C-S bond forming transformation across a diverse set of aryl and alkyl mercaptan substrates and α-diazoester carbene donors, providing high conversions (60-99%) and high numbers of catalytic turnovers (1100-5400). Furthermore, the enantioselectivity of these biocatalysts could be tuned through mutation of amino acid residues within the distal pocket of the hemoprotein, leading to myoglobin variants capable of supporting asymmetric S-H insertions with up to 49% ee. Rearrangement experiments support a mechanism involving the formation of a sulfonium ylide generated upon attack of the thiol substrate to a heme-bound carbene intermediate. This journal is
- Tyagi, Vikas,Bonn, Rachel B.,Fasan, Rudi
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p. 2488 - 2494
(2015/03/30)
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- Alkylsulfanyl-1,2,4-triazoles, a New Class of allosteric valosine containing protein inhibitors. Synthesis and structure-activity relationships
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Valosine containing protein (VCP), also known as p97, is a member of AAA ATPase family that is involved in several biological processes and plays a central role in the ubiquitin-mediated degradation of misfolded proteins. VCP is an ubiquitously expressed, highly abundant protein and has been found overexpressed in many tumor types, sometimes associated with poor prognosis. In this respect, VCP has recently received a great deal of attention as a potential new target for cancer therapy. In this paper, the discovery and structure-activity relationships of alkylsulfanyl-1,2,4-triazoles, a new class of potent, allosteric VCP inhibitors, are described. Medicinal chemistry manipulation of compound 1, identified via HTS, led to the discovery of potent and selective inhibitors with submicromolar activity in cells and clear mechanism of action at consistent doses. This represents a first step toward a new class of potential anticancer agents.
- Polucci, Paolo,Magnaghi, Paola,Angiolini, Mauro,Asa, Daniela,Avanzi, Nilla,Badari, Alessandra,Bertrand, Jay,Casale, Elena,Cauteruccio, Silvia,Cirla, Alessandra,Cozzi, Liviana,Galvani, Arturo,Jackson, Peter K.,Liu, Yichin,Magnuson, Steven,Malgesini, Beatrice,Nuvoloni, Stefano,Orrenius, Christian,Sirtori, Federico Riccardi,Riceputi, Laura,Rizzi, Simona,Trucchi, Beatrice,O'Brien, Tom,Isacchi, Antonella,Donati, Daniele,D'Alessio, Roberto
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p. 437 - 450
(2013/04/10)
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- Copper-Catalyzed Synthesis of α-Thioaryl Carbonyl Compounds Through S-S and C-C Bond Cleavage
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A method to access α-thioaryl ketones and α-thioaryl esters employing copper acetate (hydrate) as catalyst and readily accessible diaryl disulfides and β-diketones (or β-keto esters) has been developed. Both alkyl- and aryl-substituted carbonyl compounds can be prepared. Copyright
- Zou, Liang-Hua,Priebbenow, Daniel L.,Wang, Long,Mottweiler, Jakob,Bolm, Carsten
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supporting information
p. 2558 - 2563
(2013/10/21)
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- Regioselective sy nthesis and antimicrobial evaluation of new 1-aryloxyacetyl-, 1-thiophenoxyacetyl- and 1-phenylaminoacetylsubstituted 3-alkyl(aryl/heteroaryl)-5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazoles
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This paper describes an efficient approach for the regioselective synthesis of new series of twenty 1-aryloxy(thio)acetyl and 1-(phenylamino)acetyl- substituted 5-trifluoromethyl-5-hydroxy-4,5-dihydro-1H-pyrazoles (3) in 34-96% yields from the cyclocondensation reaction of 4-alkoxy-4-alkyl-(aryl/heteroaryl) -1,1,1-trifluoroalk-3-en-2-ones with different substituted acetohydrazides. Dehydration reactions of 3, carried out in the presence of thionyl chloride, furnished two examples of aromatic 5-trifluoromethyl-1H-pyrazole derivatives, in 78-82% yields. From antimicrobial tests the fungi C. albicans proved to be particularly susceptible to the action of 1-(phenylamino)acetyl-substituted 3-alkyl-2-pyrazoline derivatives; however the first results are still weak when compared to standard drugs. ARKAT-USA, Inc.
- Bonacorso, Helio G.,Pittaluga, Everton P.,Alves, Sydney H.,Schaffer, Larissa F.,Cavinatto, Susiane,Porte, Liliane M. F.,Paim, Gisele R.,Martins, Marcos A. P.,Zanatta, Nilo
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body text
p. 62 - 75
(2012/07/31)
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- Synthesis and antimicrobial screening of some 3-(phenylsulfonyl)- 2H-chromen-2-ones
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In this study, we have investigated the synthetic routes for the preparation of 3-sulfonyl coumarin 3 starting from phenylsulfonyl acetate 2 in the presence of mild base pyridine and piperidine and simple peroxide oxidation of sulphide 6 to sulfones 7 and their antimicrobial activities.
- Edayadulla,Babu,Ramesh
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- Catalytic activation of diazo compounds using electron-rich, defined iron complexes for carbene-transfer reactions
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Carbene transfer: The electron-rich iron complex Bu4N[Fe(CO) 3(NO)] efficiently catalyzes different carbene-transfer reactions. Various diazo compounds can be used. The high stability of the employed iron complexes is demonstrated by the generation of the diazo reagent in situ and a sequential iron-catalyzed allylic sulfenylation/Doyle-Kirmse reaction. Copyright
- Holzwarth, Michael S.,Alt, Isabel,Plietker, Bernd
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supporting information; experimental part
p. 5351 - 5354
(2012/07/14)
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- Iron-catalyzed synthesis of glycine derivatives via carbon-nitrogen bond cleavage using diazoacetate
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Treatment of tertiary amines with diazoacetate in the presence of a catalytic amount of an iron salt, FeCl3, in ethanol gave glycine derivatives. In this reaction, a carbon-nitrogen single bond of the amine was cleaved. The Royal Society of Chemistry 2010.
- Kuninobu, Yoichiro,Nishi, Mitsumi,Takai, Kazuhiko
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supporting information; scheme or table
p. 8860 - 8862
(2011/02/28)
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- On the reactivity of indium(III) benzenechalcogenolates (chalcogen = sulfur and selenium) towards organyl halides for the synthesis of organyl phenyl chalcogenides
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The reactivity of indium(III) benzenechalcogenolates (chalcogen = sulfur, selenium) towards organyl halides (organyl = alkyl, allyl, benzyl, acyl) was examined. A practical one-pot method to prepare organyl phenyl chalcogenides indium metal and diphenyl dichalcogenide was found. The coupling is fairly broad in scope and generally works better organyl halides capable to produce stable carbocations.
- Peppe, Clovis,Borges De Castro, Lierson
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experimental part
p. 678 - 683
(2009/10/30)
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- Synthesis of some novel bioactive 4-oxy/thio substituted-1H-pyrazol-5(4H)-ones via efficient cross-Claisen condensation
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α-Oxy/thio substituted-β-keto esters were synthesized through an efficient cross-Claisen condensation of aryl oxy/thio acetic acid ethyl esters with acid chlorides, then it is converted in situ into 4-oxy/thio substituted-1H-pyrazol-5(4H)-ones by the addition of hydrazine or hydrazine derivatives and screened for their antibacterial, antifungal activities.
- Venkat Ragavan,Vijayakumar,Suchetha Kumari
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experimental part
p. 3852 - 3857
(2009/12/04)
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- Triton B-mediated mild, convenient, and efficient method for the selective alkylation of cyclic secondary amines and thiols
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Alkylation of cyclic secondary amines, thiols, and pyridazinones has been demonstrated with alkyl halides using Triton B as base and reaction medium.
- Meshram,Reddy, B. Chennakesava,Goud, P. Ramesh
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experimental part
p. 2297 - 2303
(2009/12/01)
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- Iron(III) corroles and porphyrins as superior catalysts for the reactions of diazoacetates with nitrogen- or sulfur-containing nucleophilic substrates: Synthetic uses and mechanistic insights
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A thorough mechanistic investigation has been performed on the reactions of primary and secondary amines with diazoacetates, which proceed uniquely quickly and efficiently when catalyzed by iron(III) corroles and porphyrins. Two major differences in relation to other metal-based catalysts are that the iron complexes are not poisoned by excess amine and that metal-carbene intermediates are apparently not involved in the reaction pathway. The results instead point towards nitrogen ylide intermediates formed by nucleophilic attack of the amines on diazoacetate-coordinated iron complexes. Nitrogen ylides are also formed when allyl- and propargylsubstituted tertiary amines react with diazoacetates, a scenario that smoothly leads to 2,3-rearrangement reaction products with catalytic amounts of the iron(III) complexes. Similar findings regarding the superiority of the iron-(III) complexes (in terms of catalyst loading, chemical yields, and reaction conditions) were obtained with thiols (S-H insertion) and sulfides (2,3-rear-rangement reactions), which suggest similar mechanisms operate in these cases.
- Aviv, Iris,Gross, Zeev
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scheme or table
p. 3995 - 4005
(2009/05/26)
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- Facile stereoselective synthesis of cis- and trans-3-alkoxyazetidin-2-ones
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A highly stereoselective synthesis of cis- and trans-3-alkoxy-3-phenyl/benzylthioazetidin-2-ones is described. The reaction of α-chlorosulfide-β-lactams with various alcohols catalyzed by a Lewis acid such as ZnCl2 in the presence of molecular
- Bhalla, Aman,Venugopalan, Paloth,Bari, Shamsher S.
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p. 8291 - 8302
(2007/10/03)
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- TETRAHYDROCARBAZOLES AND DERIVATIVES
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The present invention relates to compounds of the formula (I) wherein R1, R2, R3, R4, R5, X1, X2, X3, X4, n, and k are defined in the description and claims, and pharmaceutically acceptable salts and/or pharmaceutically acceptable esters thereof. The compounds are useful for in the treatment and prophylaxis of diseases which are modulated by LXRα and/or LXR? agonists, including increased lipid and cholesterol levels, particularly low HDL-cholesterol, high LDL-cholesterol, atherosclerotic diseases, diabetes, particularly non-insulin dependent diabetes mellitus, metabolic syndrome, dyslipidemia, Alzheimer's disease, sepsis, inflammatory diseases such as colitis, pancreatitis, cholestasis/fibrosis of the liver, and diseases that have an inflammatory component such as Alzheimer's disease or impaired/improvable cognitive function.
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Page/Page column 120
(2010/02/14)
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- Ionic liquid as catalyst and reaction medium: A simple, convenient and green procedure for the synthesis of thioethers, thioesters and dithianes using an inexpensive ionic liquid, [pmIm]Br
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An easily accessible and inexpensive room temperature ionic liquid, 1-pentyl-3-methylimidazolium bromide, [pmIm]Br efficiently catalyzes the reaction of alkyl halides or acyl halides with thiols without any solvent at room temperature leading to the synthesis of thioethers and thioesters in high yields. This reaction has also been extended for the preparation of dithianes and transthioetherification. The ionic liquid is recovered and recycled for subsequent runs.
- Ranu, Brindaban C.,Jana, Ranjan
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p. 1811 - 1818
(2007/10/03)
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- Heterocyclic compounds as P2X7 ion channel blockers
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The present invention relates to a novel series of 4,5-diphenyl-2-amino-4,5-dihydro-imidazole derivatives of the formula II: 1 wherein R, R1, R2, R3, R4, R5, X and Y are as defined herein. This invention also relates to methods of making these compounds. The compounds of this invention are P2X7 ion channel blockers and are therefore useful as pharmaceutical agents, especially in the treatment and/or prevention of a variety of diseases having an inflammatory component, including inflammatory bowel disease, rheumatoid arthritis and disease conditions associated with the central nervous system, such as stroke, Alzheimer''s disease, etc.
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Page/Page column 77
(2010/02/10)
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- Selective deoxygenation of sulfoxides to sulfides with phosphites catalyzed by dichlorodioxomolybdenum(VI)
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Chemoselective deoxygenation of sulfoxides to sulfides was carried out by P(OPh)3 in mild conditions catalyzed by dichlorodioxomolybdenum(VI).
- Sanz, Roberto,Escribano, Jaime,Aguado, Rafael,Pedrosa, Maria R.,Arnaiz, Francisco J.
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p. 1629 - 1632
(2007/10/03)
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- Indium(I) iodide-promoted cleavage of diaryl diselenides and disulfides and subsequent condensation with alkyl or acyl halides. One-pot efficient synthesis of diorganyl selenides, sulfides, selenoesters, and thioesters
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Diphenyl diselenides and disulfides undergo facile cleavages by indium(I) iodide and the corresponding generated selenate and thiolate anions condense in situ with alkyl or acyl halides present in the reaction mixture. Thus, a simple, efficient, and general procedure has been developed for the synthesis of unsymmetrical diorganyl selenides, sulfides (thioethers), selenoesters, and thioesters by this one-pot reaction at room temperature.
- Ranu, Brindaban C.,Mandal, Tanmay
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p. 5793 - 5795
(2007/10/03)
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- An efficient synthesis of aryloxyacetic acid and arylthioacetic acid esters
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The esterification of the aryloxyacetic acid and arylthioacetic acid catalysed by silica sulfuric acid results aryloxyacetic acid and arylthioacetic acid ester in 83-94% yields respectively under mild reaction conditions.
- Li, Ji-Tai,Li, Hong-Ya,Li, Hui-Zhang
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p. 416 - 417
(2007/10/03)
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- Fluorination of α-phenylsulfanyl esters using difluoroiodotoluene
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Treatment of α-phenylsulfanyl esters 11-14 with one equivalent of difluoroiodotoluene 3a produced the α-fluoro sulfides 17-20 in good overall yield through a Fluoro-Pummerer reaction. A second equivalent of reagent produced α,α-difluoro sulfides and a third led to α,α-difluoro sulfoxides. An identical pattern of reactivity was observed with the α-phenylsulfanyl lactone 26. This sequential fluorination-oxidation behaviour was exploited in the one-pot synthesis of 3-fluoro-2(5H)-furanone 33 starting from α-phenylsulfanylbutyrolactone 32.
- Motherwell, William B.,Greaney, Michael F.,Tocher, Derek A.
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p. 2809 - 2815
(2007/10/03)
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- Pummerer-type α-functionalization of arylseleninylacetates by treating with trimethylsilyl- or tri-n-butylstannyl-masked nucleophiles and trifluoroacetic anhydride or a Lewis acid
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Arylseleninylacetates underwent facile α-functionalization on treatment with trimethylsilyl- or tri-n-butylstannyl-masked nucleophiles and trifluoroacetic anhydride (TFAA) or a Lewis acid. (C) 2000 Elsevier Science Ltd.
- Shimada, Kazuaki,Kikuta, Yutaka,Koganebuchi, Hiroyuki,Yonezawa, Fumi,Aoyagi, Shigenobu,Takikawa, Yuji
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p. 4637 - 4640
(2007/10/03)
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- Synthesis of phenylthiomethyl compounds from trichloromethyl derivatives
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A new method for the conversion of trichloromethyl compounds into the corresponding phenylthiomethyl derivatives by reaction with sodium thiophenolate in the presence of thiophenol is described. This transformation proceeds at room temperature in high yield and has been applied to a variety of trichloromethyl compounds.
- Romero-Ortega, Moises,Fuentes, Aydee,Gonzalez, Carlos,Morales, David,Cruz, Raymundo
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p. 225 - 227
(2007/10/03)
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- A new method for the reductive cleavage of S-S bond by the system of Cp2TiCl2/i-BuMgBr/THF and its application in synthesis of α-alkylthio carbonyl compounds
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The reduction of disulfides by Cp2TiCl2/i-BuMgBr/THF led to nucleophilic sulfides [Cp2TiSR]. This species reacted with α-bromo carbonyl compounds to give α-alkylthio carbonyl compounds in high yields.
- Huang,Zheng
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p. 1297 - 1301
(2007/10/03)
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- Insertion of ethyl diazoacetate into N-H and S-H bonds catalyzed by ruthenium porphyrin complexes
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Ruthenium porphyrin complexes catalyze insertion of ethyl diazoacetate into sulfur-hydrogen and nitrogen-hydrogen bonds under mild conditions and with reasonable to very good yields.
- Galardon, Erwan,Le Maux, Paul,Simonneaux, Gerard
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p. 2455 - 2456
(2007/10/03)
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- Organic reactions catalyzed by methylrhenium trioxide: Reactions of ethyl diazoacetate and organic azides
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Methylrhenium trioxide (CH3ReO3 or MTO) catalyzes several classes of reactions of ethyl diazoacetate, EDA. It is the first high valent oxo complex for carbene transfer. Under mild conditions and in the absence of other substrates, EDA was converted to a 9:1 mixture of diethyl maleate and diethyl fumarate. In the presence of alcohols, α-alkoxy ethyl acetates were obtained in good yield. The yields dropped for the larger and more branched alcohols, the balance of material being diethyl maleate and fumarate. An electron-donating group in the para position of phenols favors the formation of α-phenoxy ethyl acetates. The use of EDA to form α-thio ethyl acetates and N-substituted glycine ethyl esters, on the other hand, is hardly affected by the size or structure of the parent thiol or amine, with all of these reactions proceeding in high yield. MTO-catalyzed cycloaddition reactions occur between EDA and aromatic imines, olefins, and carbonyl compounds. Three-membered ring products are formed: aziridines, cyclopropanes, and epoxides, respectively. The reactions favor the formation of trans products, and provide a convenient route for the preparation of aziridines. Intermediate carbenoid and nitrenoid species have been proposed. In the presence of an oxygen source such as an epoxide, ethyl diazoacetate and azibenzil are converted to an oxalic acid monoethyl ester and tobenzil; at the same time the epoxide was converted to an olefin. These results provide further support for the proposed intermediate, a cyclic species containing Re, O, and CHCO2Et (or, occasionally, CPhC(O)Ph)in a three-membered ring.
- Zhu, Zuolin,Espenson, James H.
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p. 9901 - 9907
(2007/10/03)
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- Transformation of Alkyl N-(Vinyloxy)benzimidates to Alkyloxazoles. Mechanism and Extension
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Transformation of alkyl N-(vinyloxy)benzimidates to alkyloxazoles proceeds through the intermediates: a charge-separated 1,2-oxazetidine derivative and then 1-hydroxy-2-imino>maleic acid diester, while their photochemical transformation takes place via a concerted sigmatropic shift.As the extension of this reaction, the preparation of the precursor proposed for virginiamycin M2 synthesis and the reaction of N-analogs of alkyl N-(vinyloxy)benzimidates are described.
- Yokoyama, Masataka,Menjo, Yasuhiro,Ubukata, Makoto,Irie, Masakazu,Watanabe, Mikari,Togo, Hideo
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p. 2219 - 2226
(2007/10/02)
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