Month: December 2022

Han, Dong published the artcileAsymmetric Epoxidation of Unfunctionalized Olefins Catalyzed by Chiral (Pyrrolidine Salen) Mn (III) Complexes with Proline Sidearms, Computed Properties of 71989-31-6, the publication is Molecular Catalysis (2022), 112268, database is CAplus.

Four (R, R)-3, 4-diaminopyrrolidine-based chiral Salen ligands with L-Boc-N-proline, D-Boc-N-proline, L-proline, D-proline as resp. sidearms, as well as their manganese complexes were synthesized and characterized. These Salen-Mn(III) complexes were applied to the asym. epoxidations of unfunctionalized olefins with NaClO, and m-CPBA as resp. oxidants. The catalysis of the Salen-Mn (III) complexes varied with the change of sidearms. The one with D-Boc-N-proline as a sidearm showed the best asym. catalysis among the four chiral manganese complexes, and its catalysis was also better than that of the one with a benzyl sidearm, and comparable with that of Jacobsen’s catalyst. Moderate to excellent enantioselectivities and yields were achieved in the asym. of various olefins over this complex. The big enhancement of the D-Boc-N-proline sidearm on the enantioselectivity of the asym. epoxidation might be ascribed to its large steric hindrance and appropriate configuration, allowing the Boc moiety to be away from the side-on approach pathway of olefins to the active center but near the opposite side one in some degree, thus facilitating the approach of olefins to the active center from one direction.

Molecular Catalysis published new progress about 71989-31-6. 71989-31-6 belongs to catalysis-chemistry, auxiliary class Amino acide derivatives,pyrrolidine, name is Fmoc-Pro-OH, and the molecular formula is C20H19NO4, Computed Properties of 71989-31-6.

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

Lei, Jie published the artcileExpeditious access of chromone analogues via a Michael addition-driven multicomponent reaction, COA of Formula: C8H7NO4, the publication is Organic Chemistry Frontiers (2020), 7(8), 987-992, database is CAplus.

A Michael addition-driven four-component reaction (4-CR) was developed for derivatizing chromones by strategically suppressing competing 4-CR Ugi reaction without a catalyst. A series of structurally diverse 4-oxochroman-2-carboxamides was synthesized with this one-pot protocol. In addition, the new reaction was expanded for the synthesis of a series of tetrazole substituted chromones by replacing carboxylic acid with trimethylsilyl azide (TMSN₃). The imine functional group and the corresponding aldehyde hydrolyzed from the imine were utilized for further structural diversification.

Organic Chemistry Frontiers 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

Hong, Huanliang published the artcileElectrochemical Synthesis Strategy for C_vinyl-CF₃ Compounds through Decarboxylative Trifluoromethylation, Quality Control of 1772-76-5, the publication is Journal of Organic Chemistry (2019), 84(9), 5980-5986, database is CAplus and MEDLINE.

An efficient decarboxylative trifluoromethylation of ¦Á,¦Â-unsaturated carboxylic acids using the Langlois reagent as a trifluoromethyl precursor has been achieved by an electro-oxidative strategy. Under catalyst-free and external oxidant-free electrolysis conditions, a series of C_vinyl-CF₃ compounds are obtained with a high regioselectivity in good yields. The successful trapping of the CF₃ radical by a scavenger has confirmed that radical processes are involved in this system.

Journal of Organic Chemistry 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, Quality Control of 1772-76-5.

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

Nakano, Akio published the artcileCistulynes: proton NMR and single-crystal x-ray evidence for structure and cation encapsulation in a rigid, molecular channel model system, Recommanded Product: Propane-1,3-diamine dihydrochloride, the publication is Tetrahedron Letters (1989), 30(38), 5099-102, database is CAplus.

A novel, tetraacetylenic, macrotricyclic mol. receptor I, prepared by dimerization of N,N‘-dipropargyl-4,13-diaza-18-crown-6 with CuCl in the presence of Me₂NCH₂CH₂NMe₂, O, and Me₂CHOH in 12% yield, is shown by x-ray crystallog. to have a channel-like structure and by NMR techniques to selectively accommodate both metallic and organic cations within its compartment.

Tetrahedron Letters published new progress about 10517-44-9. 10517-44-9 belongs to catalysis-chemistry, auxiliary class Salt,Amine,Aliphatic hydrocarbon chain, name is Propane-1,3-diamine dihydrochloride, and the molecular formula is C3H12Cl2N2, Recommanded Product: Propane-1,3-diamine dihydrochloride.

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

Li, Mao-Lin published the artcileCarboxyl Group-Directed Iridium-Catalyzed Enantioselective Hydrogenation of Aliphatic ¦Ã-Ketoacids, HPLC of Formula: 2051-95-8, the publication is ACS Catalysis (2020), 10(17), 10032-10039, database is CAplus.

Although the transition metal-catalyzed asym. hydrogenation of aromatic ketones has been extensively explored, the enantioselective hydrogenation of aliphatic ketones remains a challenge because chiral catalysts cannot readily discriminate between the re and si faces of these ketones. Herein, we report a carboxyl-directing strategy for the asym. hydrogenation of aliphatic ¦Ã-ketoacids. With catalysis by iridium complexes bearing chiral spiro phosphino-oxazoline ligands, hydrogenation of aliphatic ¦Ã-ketoacids afforded chiral ¦Ã-hydroxylacids with high enantioselectivity (up to 99% ee). Mechanistic studies revealed that the carboxyl group of the substrate directs hydrogen transfer and ensures high enantioselectivity. D. functional theory calculations suggested the occurrence of chiral induction involving a hydrogen-hydrogen interaction between a hydride on the iridium atom and the substituent on the oxazoline ring of the ligand, and on the basis of the calculations, we proposed a catalytic cycle involving only Ir(III), which differs from the Ir(III)/Ir(V) catalytic cycle that operates in the hydrogenation of ¦Á,¦Â-unsaturated carboxylic acids.

ACS Catalysis 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 C10H10O3, HPLC of Formula: 2051-95-8.

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

Fu, Hongxia published the artcileRatiometric Fluorescence Azide-Alkyne Cycloaddition for Live Mammalian Cell Imaging, Recommanded Product: 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate, the publication is Analytical Chemistry (Washington, DC, United States) (2015), 87(22), 11332-11336, database is CAplus and MEDLINE.

Click chem. with metabolic labeling has been widely used for selectively imaging biomacromols. in cells. The first example of azide-alkyne cycloaddition for ratiometric fluorescent imaging of live cells is reported. The precursor of the azido fluorophore (cresyl violet) has a fluorescence emission peak at 620 nm. The electron-rich nitrogen of the azido group blue-shifts the emission peak to 566 nm. When the click reaction occurs, an emission peak appears at 620 nm due to the lower electronic d. of the newly formed triazole ring, which allows the authors to ratiometrically record fluorescence signals. This emission shift was applied to ratiometric imaging of propargylcholine- and dibenzocyclooctyne-labeled human breast cancer cells MCF-7 under laser confocal microscopy. Two typical triazole compounds were isolated for photophys. parameter measurements. The emission spectra presented a fluorescence emission peak around 620 nm for both click products. The results further confirmed the emission wavelength change was the result of azide-alkyne cycloaddition reaction. Since nearly all biomols. can be metabolically labeled by reported alkyne-functionalized derivatives of native metabolites, the authors’ method can be readily applied to image these biomacromols.

Analytical Chemistry (Washington, DC, United States) published new progress about 10510-54-0. 10510-54-0 belongs to catalysis-chemistry, auxiliary class Other Aromatic Heterocyclic,Salt,Amine,Inhibitor,Inhibitor, name is 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate, and the molecular formula is C18H15N3O3, Recommanded Product: 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate.

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

Li, Xia published the artcile3-D supramolecular frameworks assembled by lanthanide binuclear molecules based on 1,2-phenylenedioxydiacetic acid and 1,10-phenanthroline, Computed Properties of 5411-14-3, the publication is Inorganic Chemistry Communications (2008), 11(7), 779-782, database is CAplus.

[Ln₂(PDOA)₃(phen)₂(H₂O)₂]¡¤2H₂O (Ln = Eu (1), Tb (2), and Dy (3); H₂PDOA = 1,2-phenylenedioxydiacetic acid; phen = 1,10-phenanthroline) were synthesized and structurally characterized by single crystal x-ray diffraction methods. The three complexes are all binuclear mols. The two Ln(III) centers are linked by only one PDOA ligand through its two bidentate-chelating carboxylate groups. PDOA also acts as a terminal ligand using one carboxylate oxygen and ether oxygen atoms to chelate the Ln(III) ion. 3-Dimensional supramol. frameworks are built up by the hydrogen bonds and ¦Ð-¦Ð stacking interactions. The fluorescent spectra of the three complexes show the characteristic emission of the Eu(III) for 1, Tb(III) for 2, and Dy(III) for 3, resp.

Inorganic Chemistry Communications published new progress about 5411-14-3. 5411-14-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 2,2-(1,2-Phenylenebis(oxy))diacetic acid, and the molecular formula is C10H10O6, Computed Properties of 5411-14-3.

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

Liu, Guo-Cheng published the artcileMetal-induced various properties and structures of complexes based on methylene-derived diamide and S₂-bridged carboxylate, Product Details of C14H10O4S2, the publication is Polyhedron (2019), 294-302, database is CAplus.

By introducing different metal ions, six new coordination polymers (CPs) [Zn(L)_0.5(DTSA)]¡¤H₂O (CP1), [Cd(L)_0.5(DTSA)(H₂O)] (CP2), [Mn(L)_0.5(DTSA)(H₂O)] (CP3), [Co(L)_0.5(DTSA)(H₂O)] (CP4), [Ni(L)_0.5(DTSA)(H₂O)] (CP5), [Pb₂(L)_0.5(DTSA)₂] (CP6), [N,N’-bis(4-methylenepyridin-4-yl)-1,4-benzenedicarboxamide (L), 2,2′-dithiodibenzoic acid (H₂DTSA)] were synthesized under hydrothermal conditions. CP1 is a unified node (4,4)-connected network derived from Zn₂ nodes, pairs of DTSA anions and ¦Ì₂-L linkers. CP2-CP5 display similar binode (4,4)-connected layers based on single metal centers, ¦Ì₂-DTSA anions and ¦Ì₄-L linkers. CP6 show a novel 3-dimensional (3,4,4,5)-connected Pb-based framework, which is constructed form Pb-DTSA layers and ¦Ì₄-L linkers. The effect of metal ions on the architectures of the title complexes was studied. CP1, CP2 and CP6 are efficient luminescent sensors for the detection of Fe³⁺ ions (CP1 and CP2) and DMSO (CP1 and CP6). CP3-CP5 show different electrochem. response to nitrite and bromate in water solution

Polyhedron 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 C14H10O4S2, Product Details of C14H10O4S2.

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

Goldkamp, Anna K. published the artcileCharacterization of tRNA expression profiles in large offspring syndrome, Recommanded Product: (S)-2-Amino-4-(methylthio)butanoic acid, the publication is BMC Genomics (2022), 23(1), 273, database is CAplus and MEDLINE.

Assisted Reproductive Technologies (ART) use can increase the risk of congenital overgrowth syndromes, such as large offspring syndrome (LOS) in ruminants. Epigenetic variations are known to influence gene expression and differentially methylated regions (DMRs) were previously determined to be associated with LOS in cattle. We observed DMRs overlapping tRNA clusters which could affect tRNA abundance and be associated with tissue specificity or overgrowth. Variations in tRNA expression have been identified in several disease pathways suggesting an important role in the regulation of biol. processes. Understanding the role of tRNA expression in cattle offers an opportunity to reveal mechanisms of regulation at the translational level. We analyzed tRNA expression in the skeletal muscle and liver tissues of day 105 artificial insemination-conceived, ART-conceived with a normal body weight, and ART-conceived bovine fetuses with a body weight above the 97th percentile compared to Control-AI. Despite the centrality of tRNAs to translation, in silico predictions have revealed dramatic differences in the number of tRNA genes between humans and cattle (597 vs 1,659). Consistent with reports in human, only a fraction of predicted tRNA genes are expressed. We detected the expression of 474 and 487 bovine tRNA genes in the muscle and liver with the remainder being unexpressed. 193 and 198 unique tRNA sequences were expressed in all treatment groups within muscle and liver resp. In addition, an average of 193 tRNA sequences were expressed within the same treatment group in different tissues. Some tRNA isodecoders were differentially expressed between treatment groups. In the skeletal muscle and liver, we categorized 11 tRNA isoacceptors with undetected expression as well as an isodecoder that was unexpressed in the liver (SerGGA). Our results identified variation in the proportion of tRNA gene copies expressed between tissues and differences in the highest contributing tRNA anticodon within an amino acid family due to treatment and tissue type. Out of all amino acid families, roughly half of the most highly expressed tRNA isoacceptors correlated to their most frequent codon in the bovine genome. Although the number of bovine tRNA genes is nearly triple of that of the tRNA genes in human, there is a shared occurrence of transcriptionally inactive tRNA genes in both species. We detected differential expression of tRNA genes as well as tissue- and treatment- specific tRNA transcripts with unique sequence variations that could modulate translation during protein homeostasis or cellular stress, and give rise to regulatory products targeting genes related to overgrowth in the skeletal muscle and/or tumor development in the liver of LOS individuals. While the absence of certain isodecoders may be relieved by wobble base pairing, missing tRNA species could increase the likelihood of mistranslation or mRNA degradation

BMC Genomics 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, Recommanded Product: (S)-2-Amino-4-(methylthio)butanoic acid.

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

Yang, Han published the artcileNitrogen nutrition contributes to plant fertility by affecting meiosis initiation, Category: catalysis-chemistry, the publication is Nature Communications (2022), 13(1), 485, database is CAplus and MEDLINE.

Nitrogen (N), one of the most important plant nutrients, plays crucial roles in multiple plant developmental processes. Spikelets are the primary sink tissues during reproductive growth, and N deficiency can cause floral abortion. However, the roles of N nutrition in meiosis, the crucial step in plant sexual reproduction, are poorly understood. Here, we identified an N-dependent meiotic entrance mutant with loss of function of ELECTRON TRANSFER FLAVOPROTEIN SUBUNIT ¦Â (ETF ¦Â) in rice (Oryza sativa). etf ¦Â displayed meiosis initiation defects, excessive accumulation of branched-chain amino acids (BCAAs) and decrease in total N contents in spikelets under N starvation, which were rescued by applying excess exogenous inorganic N. Under N starvation, ETF ¦Â , through its involvement in BCAA catabolism, promotes N reutilization and contributes to meeting N demands of spikelets, highlighting the impact of N nutrition on meiosis initiation. We conclude that N nutrition contributes to plant fertility by affecting meiosis initiation.

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 C14H12N2S, Category: catalysis-chemistry.

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