7605-25-6Relevant academic research and scientific papers
Byproduct formation during the biosynthesis of spinosyn A and evidence for an enzymatic interplay to prevent its formation
Choi, Sei-hyun,Franklin, Joseph Livy,Huang, Teng-Yi,Hung, Shang-Cheng,Jeon, Byung-sun,Kim, Namho,Liu, Hung-wen,Ruszczycky, Mark W.
supporting information, (2021/11/30)
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
Noncanonical Heme Ligands Steer Carbene Transfer Reactivity in an Artificial Metalloenzyme**
Dunkelmann, Daniel,Hayashi, Takahiro,Hilvert, Donald,Mittl, Peer R. E.,Ota, Yusuke,Pott, Moritz,Tinzl, Matthias
supporting information, p. 15063 - 15068 (2021/06/09)
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.
Synthesis of and characterization of some Heterocyclic Compounds derived from Thiophenol
AL-Khazraji, Shaima Ibraheem Chyad
, p. 5655 - 5662 (2021/09/11)
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.
Acridine Orange Hemi(Zinc Chloride) Salt as a Lewis Acid-Photoredox Hybrid Catalyst for the Generation of α-Carbonyl Radicals
Das, Sanju,De Sarkar, Suman,Mandal, Tanumoy
supporting information, (2021/12/10)
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.
Investigation of the effect of different linker chemotypes on the inhibition of histone deacetylases (HDACs)
Linciano, Pasquale,Benedetti, Rosaria,Pinzi, Luca,Russo, Fabiana,Chianese, Ugo,Sorbi, Claudia,Altucci, Lucia,Rastelli, Giulio,Brasili, Livio,Franchini, Silvia
, (2020/11/24)
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.
(Trifluoromethylselenyl)methylchalcogenyl as Emerging Fluorinated Groups: Synthesis under Photoredox Catalysis and Determination of the Lipophilicity
Grollier, Kevin,De Zordo-Banliat, Arnaud,Bourdreux, Flavien,Pegot, Bruce,Dagousset, Guillaume,Magnier, Emmanuel,Billard, Thierry
supporting information, p. 6028 - 6033 (2021/03/15)
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.
Catalyst-free, visible-light-promoted S-H insertion reaction between thiols and α-diazoesters
Chen, Shuwen,Huo, Congde,Liu, Cai,Ma, Ben,Song, Menghui,Wang, Ganggang,Yang, Jingya,Zhou, Hongyan
supporting information, p. 9494 - 9498 (2020/12/15)
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
Air-stable binuclear Titanium(IV) salophen perfluorobutanesulfonate with zinc power catalytic system and its application to C–S and C–Se bond formation
Wang, Lingxiao,Qiao, Jie,Wei, Jiancong,Liang, Zhiwu,Xu, Xinhua,Li, Ningbo
, (2020/01/08)
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.
Rhodium-catalyzed Sommelet-Hauser type rearrangement of α-diazoimines: Synthesis of functionalized enamides
Anbarasan, Pazhamalai,Ramachandran, Kuppan,Reddy, Angula Chandra Shekar,Reddy, Palagulla Maheswar
supporting information, p. 5649 - 5652 (2020/06/09)
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.
Gold-Catalyzed Oxidation of Thioalkynes to Form Phenylthio Ketene Derivatives via a Noncarbene Route
Sharma, Pankaj,Singh, Rahulkumar Rajmani,Giri, Sovan Sundar,Chen, Liang-Yu,Cheng, Mu-Jeng,Liu, Rai-Shung
, p. 5475 - 5479 (2019/08/01)
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
