Month: November 2022

Jin, Ruitao published the artcileIon currents through Kir potassium channels are gated by anionic lipids, Name: (S)-2-Amino-4-(methylthio)butanoic acid, the publication is Nature Communications (2022), 13(1), 490, database is CAplus and MEDLINE.

Ion currents through potassium channels are gated. Constriction of the ion conduction pathway at the inner helix bundle, the textbook gate of Kir potassium channels, has been shown to be an ineffective permeation control, creating a rift in our understanding of how these channels are gated. Here we present evidence that anionic lipids act as interactive response elements sufficient to gate potassium conduction. We demonstrate the limiting barrier to K⁺ permeation lies within the ion conduction pathway and show that this gate is operated by the fatty acyl tails of lipids that infiltrate the conduction pathway via fenestrations in the walls of the pore. Acyl tails occupying a surface groove extending from the cytosolic interface to the conduction pathway provide a potential means of relaying cellular signals, mediated by anionic lipid head groups bound at the canonical lipid binding site, to the internal gate.

Nature Communications published new progress about 63-68-3. 63-68-3 belongs to catalysis-chemistry, auxiliary class Natural product, name is (S)-2-Amino-4-(methylthio)butanoic acid, and the molecular formula is C5H11NO2S, Name: (S)-2-Amino-4-(methylthio)butanoic acid.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Wang, Huamin published the artcileElectrochemical Oxidation Enables Regioselective and Scalable ¦Á-C(sp³)-H Acyloxylation of Sulfides, Application In Synthesis of 2051-95-8, the publication is Journal of the American Chemical Society (2021), 143(9), 3628-3637, database is CAplus and MEDLINE.

A highly selective, environmentally friendly, and scalable electrochem. protocol for the construction of ¦Á-acyloxy sulfides e.g., (p-tolylthio)methyl acetate, through the synergistic effect of self-assembly-induced C(sp³)-H/O-H cross-coupling, is reported. It features exceptionally broad substrate scope, high regioselectivity, gram-scale synthesis, construction of complex mols. e.g., I, and applicability to a variety of nucleophiles such as acetic acid, cyclohexanecarboxylic acid, benzoic acid, benzotriazole, etc. Moreover, the soft X-ray absorption technique and a series of control experiments have been utilized to demonstrate the pivotal role of the self-assembly of the substrates, which indeed is responsible for the excellent compatibility and precise control of high regioselectivity in electrochem. protocol.

Journal of the American Chemical Society published new progress about 2051-95-8. 2051-95-8 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ketone, name is 3-Benzoylpropionicacid, and the molecular formula is C9H10O4, Application In Synthesis of 2051-95-8.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Li, Jie published the artcileDual-enhancement on electrochemical performance with thioacetamide as an electrolyte additive for lithium-sulfur batteries, COA of Formula: C3H8N2S, the publication is Electrochimica Acta (2021), 138041, database is CAplus.

Li-S (Li-S) batteries with high theor. specific capacity and ascendancy of raw materials are considered as a potential candidate for next-generation energy storage system. However, some intractable challenges, such as low S use caused by the loss of active materials and surface passivation resulted from the deposition of insulating products, still hinder the practical application of Li-S batteries. Herein, various types of thioamides with different mol. structures were studied as electrolyte additives to enhance the electrochem. performance of Li-S cells by adjusting the solubility of the final product, Li₂S. The thioamides that contain H in primary-amine or secondary-amine groups are prone to generate recyclable active materials. Specifically, thioacetamide (TAA) as an electrolyte additive not only provides extra reversible capacity, but also boosts the solubility of Li₂S by intermol. H bonds, alleviating the passivation of the electrode and enhancing kinetics for the conversion of polysulfide to Li₂S. Therefore, the cells with TAA additive exhibit superior cycle performance and rate performance.

Electrochimica Acta published new progress about 6972-05-0. 6972-05-0 belongs to catalysis-chemistry, auxiliary class Thiourea,Amine,Aliphatic hydrocarbon chain,Amide, name is 1,1-Dimethylthiourea, and the molecular formula is C3H8N2S, COA of Formula: C3H8N2S.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Jiao, Mengzhao published the artcileFast immobilization of human carbonic anhydrase II on Ni-based metal-organic framework nanorods with high catalytic performance, COA of Formula: C8H7NO4, the publication is Catalysts (2020), 10(4), 401, database is CAplus.

Carbonic anhydrase (CA) has received considerable attention for its ability to capture carbon dioxide efficiently. This study reports a simple strategy for immobilizing recombinant carbonic anhydrase II from human (hCA II) on Ni-based MOFs (Ni-BTC) nanorods, which was readily achieved in a one-pot immobilization of His-tagged hCA II (His-hCA II). Consequently, His-hCA II from cell lysate could obtain an activity recovery of 99% under optimal conditions. After storing for 10 days, the immobilized His-hCA II maintained 40% activity while the free enzyme lost 91% activity. Furthermore, during the hydrolysis of p-nitrophenyl acetic acid, immobilized His-hCA II exhibited excellent reusability and still retained more than 65% of the original activity after eight cycles. In addition, we also found that Ni-BTC had no fixation effect on proteins without histidine-tag. These results show that the Ni-BTC MOFs have a great potential with high efficiency for and specific binding of immobilized enzymes.

Catalysts published new progress about 104-03-0. 104-03-0 belongs to catalysis-chemistry, auxiliary class Nitro Compound,Carboxylic acid,Benzene, name is 4-Nitrophenylacetic acid, and the molecular formula is C8H7NO4, COA of Formula: C8H7NO4.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Zhu, Ru-Yi published the artcileLigand-Promoted Alkylation of C(sp³)-H and C(sp²)-H Bonds, HPLC of Formula: 1949-41-3, the publication is Journal of the American Chemical Society (2014), 136(38), 13194-13197, database is CAplus and MEDLINE.

9-Methylacridine was identified as a generally effective ligand to promote a Pd(II)-catalyzed C(sp³)-H and C(sp²)-H alkylation of simple amides with various alkyl iodides. This alkylation reaction was applied to the preparation of unnatural amino acids and geometrically controlled tri- and tetrasubstituted acrylic acids.

Journal of the American Chemical Society published new progress about 1949-41-3. 1949-41-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene, name is 2-Methyl-4-phenylbutanoic acid, and the molecular formula is C17H14N2O2, HPLC of Formula: 1949-41-3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Yuan, Ronghui published the artcileCharacterization of interfacial behaviour of ortho-positioned diaryl disulfide on silver substrates by surface-enhanced Raman scattering and electroreduction, Related Products of catalysis-chemistry, the publication is Materials Chemistry and Physics (2019), 121726, database is CAplus.

The interfacial behavior of ortho-positioned diaryl disulfide on activated silver substrates was characterized with surface-enhanced Raman scattering and electroreduction After the fracture of the disulfide bond, the diaryl disulfides interacted with Ag to form self-assembled monolayers. The peak intensity of benzene ring deformation and pH-dependence presented two types of linear relationships. The probe mol. at pH 11.5 was used to estimate the Raman enhancement factor of silver substrates. Also, the alk. media were favorable for the active intermediates of ortho-positioned diaryl disulfide to interact on the liquid-solid silver interfaces. Linear regression fitting between the reciprocals of surface coverage and those of solution concentration from reductive desorption was observed, and meaningful progress of spectroelectrochem. mechanisms was made for surface chem.

Materials Chemistry and Physics published new progress about 119-80-2. 119-80-2 belongs to catalysis-chemistry, auxiliary class sulfides,Carboxylic acid,Benzene, name is 2,2′-Dithiodibenzoic acid, and the molecular formula is C8H10BNO3, Related Products of catalysis-chemistry.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Horibe, Takahiro published the artcileEnantioselective 1,4-Addition Reaction of ¦Á,¦Â-Unsaturated Carboxylic Acids with Cycloalkanones Using Cooperative Chiral Amine-Boronic Acid Catalysts, Name: (E)-3-(3-Nitrophenyl)acrylic acid, the publication is Angewandte Chemie, International Edition (2020), 59(39), 17256-17260, database is CAplus and MEDLINE.

An enantioselective 1,4-addition of ¦Á,¦Â-unsaturated carboxylic acids with cycloalkanones has been developed by using chiral amine-boronic acid cooperative catalysts. In the presence of a chiral amine and boronic acid, cycloalkanones and carboxylic acids are activated as chiral enamines and mixed anhydrides, resp. The corresponding 1,4-adducts are obtained in high yield with high enantioselectivity. Furthermore, subsequent oxylactonization of the 1,4-adducts gives spirolactones with high diastereoselectivity.

Angewandte Chemie, International Edition published new progress about 1772-76-5. 1772-76-5 belongs to catalysis-chemistry, auxiliary class Benzenes, name is (E)-3-(3-Nitrophenyl)acrylic acid, and the molecular formula is C9H7NO4, Name: (E)-3-(3-Nitrophenyl)acrylic acid.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Dunn, Simon C. published the artcileSynthesis and Reactions of Group 4 Imido Complexes Supported by Cyclooctatetraene Ligands, Recommanded Product: 2,4,6-Triisopropylbenzenethiol, the publication is Organometallics (2006), 25(7), 1755-1770, database is CAplus.

The reactions of the pseudo-two-coordinate Ti imido complexes [Ti(N^tBu)(COT)] (1) (COT = ¦Ç⁸-C₈H₈), [Ti(N^tBu)(COT”)] (2) (COT” = ¦Ç⁸-1,4-C₈H₆(SiMe₃)₂), and [Ti(NAr)(COT)] (3) (Ar = 2,6-ⁱPr₂C₆H₃) with a variety of organic substrates are reported. Reaction of 1 with CO₂, ^tBuNCO, or ArNCO and reaction of 3 with CO₂ or ^tBuNCO afforded the organic products ^tBuNCO, ^tBuNCN^tBu, ^tBuNCNAr, ArNCO, and ArNCN^tBu, resp., and a Ti oxo species. These reactions proceeded via an initial [2 + 2] cycloaddition to form an N,O-bound intermediate [Ti{N(R)C(O)R’}(COT)], which subsequently underwent a retrocycloaddn. to give an organic product and the Ti oxo species. In contrast, reaction of 3 with ArNCO gave the N,N-bound [2 + 2] cycloaddition product [Ti{N(Ar)C(O)N(Ar)}(COT)] (7). In general, the reactions of 1 and 3 with CS₂ and isothiocyanates also resulted in an initial [2 + 2] cycloaddition to form an N,S-bound intermediate [Ti{N(R)C(S)R’}(COT)], which also subsequently underwent a retrocycloaddn. to give an organic product and a metal sulfide species. However, the N,S-bound compound [Ti{N(Ar)C(S)S}(COT)] (10) was stable to retrocycloaddn. and was isolated. Proton transfer reactions occurred between pinacol and compounds 1–3 to form the bis(alkoxide) species [Ti{OC(Me)₂C(Me)₂O}(COT)] (11) (from 1 or 3) or [Ti{OC(Me)₂C(Me)₂O}(COT”)] (12) (from 2) and the corresponding free amine. The reactions between 1–3 and 2 equiv of the thiols ^tBuSH and HS-2,4,6-ⁱPr₃C₆H₂ all resulted in the oxidation of the thiol to the disulfides ^tBuS-S^tBu and (2,4,6-ⁱPr₃C₆H₂)S-S(2,4,6-ⁱPr₃C₆H₂). Treatment of 1 with ^tBuNC in the presence of 1,3,5,7-cyclooctatetraene led to formal nitrene group transfer and the formation of the Ti(II) species [Ti(COT)(¦Ç⁴-C₈H₈)] (13) and ^tBuNCN^tBu. The analogous reactions between 2 and 3 and ^tBuNC gave [Ti(N^tBu)(COT”)(CN^tBu)] (15) and [Ti(NAr)(COT)(CN^tBu)] (17), and similarly the reaction between 1 and pyridine gave [Ti(N^tBu)(COT)(py)] (19) (py = pyridine). Complex 19 was crystallog. characterized. DFT studies indicated that the interaction between pyridine and the Ti center in 19 and ^tBuNC and the Ti center in 17 was electrostatic in nature. [Ti(NR)(COT)(AlMe_3-xCl_x)] (R = ^tBu, x = 0 (20); R = Ar, x = 0 (21); R = ^tBu, x = 1 (22); R = Ar, x = 1 (23)) were formed through the reactions of 1 and 3 with AlMe₃ and AlMe₂Cl, and DFT studies indicated that they contained four-membered metallacyclic rings. Attempts to prepare monomeric Zr imido cyclooctatetraene complexes through the reactions of [Zr₂(¦Ì-NR)₂Cl₄(THF)_x] (R = ^tBu, x = 3; R = 2,6-Me₂C₆H₃(Ar’), x = 4) with K₂COT, Li₂COT”¡¤1.8(THF), or Li₂[COT^*] (COT^* = 1,4-C₈H₆(SiMe₂^tBu)₂) were unsuccessful. Only the crystallog. characterized dimeric species [Zr₂(¦Ì-NAr’)₂(COT”)₂] (24) was isolated.

Organometallics published new progress about 22693-41-0. 22693-41-0 belongs to catalysis-chemistry, auxiliary class Other Functionalization Reagent, name is 2,4,6-Triisopropylbenzenethiol, and the molecular formula is C15H24S, Recommanded Product: 2,4,6-Triisopropylbenzenethiol.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Tamao, Kohei published the artcileAnion complexation by bidentate Lewis acidic hosts, ortho-bis(fluorosilyl)benzenes, SDS of cas: 312-40-3, the publication is Journal of Organometallic Chemistry (1996), 506(1-2), 85-91, database is CAplus.

Ortho-bis(fluorosilyl)benzenes (precursors for bis-siliconates: o-C₆H₄(SiPhF₂)₂ (1), o-C₆H₄(SiF₃)(SiPh₂F) (2), o-C₆H₄(SiPhF₂)(SiPh₂F) (3)) possess anion binding properties as bidentate Lewis acidic hosts in organic solvents. Compound 1 quant. binds a F^– ion from KF suspended in acetone or THF without support of 18-crown-6 to form the corresponding soluble bis-siliconate [o-C₆H₄(SiPhF₂)₂F]K (4). The binding constants of F^– by a series of fluorosilanes were measured by ¹H and ¹⁹F NMR spectroscopies. The affinity of fluorosilanes towards F^– increases in the order PhMeSiF₂ (7)<Ph₂SiF₂ (9)<3<1<2. The fluoride ion binding constant of 2 is estimated to be K > 1.1 ¡Á 10⁹ M^-1 at 193 K. These bidentate Lewis acids 1–3 are among the strongest organic hosts for a fluoride ion in organic solvents ever reported.

Journal of Organometallic Chemistry published new progress about 312-40-3. 312-40-3 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Difluorodiphenylsilane, and the molecular formula is C13H16O2, SDS of cas: 312-40-3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Tamao, Kohei published the artcileElectronic and steric effects in pentacoordinate anionic diorganotrifluorosilicates: x-ray structures and carbon-13 NMR studies for evaluation of charge distribution in aryl groups on silicon, Quality Control of 312-40-3, the publication is Organometallics (1992), 11(1), 182-91, database is CAplus.

A series of diorganotrifluorosilicates, (4-XC₆H₄)MeSiF₃^– (I), (4-XC₆H₄)PhSiF₃^– (II), (Me_nC₆H_5-n)PhSiF₃^–, (2-MeC₆H₄)(4-MeC₆H₄)SiF₃^– (III), and (2,6-Me₂C₆H₃)(3,5-Me₂C₆H₃)SiF₃^– (IV) with the 18-crown-6 potassium countercation were prepared Mol. structures of II (X = CF₃, Me, MeO, Me₂N), III, and IV were determined by X-ray crystallog., confirming trigonal-bipyramidal structures. The dihedral angle between the substituted Ph group and the equatorial plane depends not on the electronic effect but on the steric effect. Variable-temperature ¹⁹F NMR studies on II provide the electronic effects on energy barriers for pseudorotation. In ¹³C NMR studies, all carbon chem. shifts were observed and assigned unambiguously: the Si ipso carbons of aromatic rings and the Me group were observed for the first time. Changes in chem. shifts ¦¤¦Ä(C) of anionic pentacoordinate silicates, I and II, vs. the corresponding neutral tetracoordinate silanes are +17 to +20 ppm for Si ipso (C1), +3 to +4 ppm for ortho (C2), -3 ppm for meta (C3), -4 to -7 ppm for para (C4), and +9 ppm for Me carbon. The charge distribution in the Ph groups in silicates is discussed in terms of the electron-donating nature by the SiRF₃^– group via the ¦Ð polarization effect. There are linear correlations of the chem. shifts of Si ipso C1 (para to X) in the para-substituted Ph groups and Si ipso C1′ in the parent Ph groups in II and (4-XC₆H₄)PhSiF₂ with the Hammett ¦Ò_p⁺, from which are estimated the relative electron densities on Si ipso carbons C1 and C1′.

Organometallics published new progress about 312-40-3. 312-40-3 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Difluorodiphenylsilane, and the molecular formula is C9H7NO2, Quality Control of 312-40-3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia