Catalysis-chemistry

Steinmetz, Fabian P. published the artcileMethods for assigning confidence to toxicity data with multiple values – Identifying experimental outliers, Category: catalysis-chemistry, the publication is Science of the Total Environment (2014), 358-365, database is CAplus and MEDLINE.

The assessment of data quality is a crucial element in many disciplines such as predictive toxicol. and risk assessment. Currently, the reliability of toxicity data is assessed on the basis of testing information alone (adherence to Good Laboratory Practice (GLP), detailed testing protocols, etc.). Common practice is to take one toxicity data point per compound – usually the one with the apparently highest reliability. All other toxicity data points (for the same experiment and compound) from other sources are neglected. To show the benefits of incorporating the “less reliable” data, a simple, independent, statistical approach to assess data quality and reliability on a math. basis was developed. A large data set of toxicity values to Aliivibrio fischeri was assessed. The data set contained 1813 data points for 1227 different compounds, including 203 identified as non-polar narcotic. Log K_OW values were calculated and non-polar narcosis quant. structure-activity relationship (QSAR) models were built. A statistical approach to data quality assessment, which is based on data outlier omission and confidence scoring, improved the linear QSARs. The results indicate that a beneficial method for using large data sets containing multiple data values per compound and highly variable study data has been developed. Furthermore this statistical approach can help to develop novel QSARs and support risk assessment by obtaining more reliable values for biol. endpoints.

Science of the Total Environment 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 C2H2N4O2, Category: catalysis-chemistry.

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

Ruhlandt-Senge, Karin published the artcileSynthesis and characterization of the first discrete potassium thiolates displaying three different coordination spheres at potassium in one molecule, Name: 2,4,6-Triisopropylbenzenethiol, the publication is Chemical Communications (Cambridge) (1996), 147-48, database is CAplus.

Potassium hydride reacts with HSC₆H₂Prⁱ₃-2,4,6 (HSR) in THF or THF-tmen (tmen = N,N,N’,N’-tetramethylethylenediamine) to afford the first discrete, hexameric potassium thiolates [{K(SR)}₂{K(THF)(SR)}₂{K(THF)₂(SR)}₂] and [{K(SR)}₂{K(THF)(SR)}₂{K(tmen)(SR)}₂]¡¤THF, exhibiting an unusual box-shaped structure with three different coordination spheres for the three independent potassium atoms.

Chemical Communications (Cambridge) 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, Name: 2,4,6-Triisopropylbenzenethiol.

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

Ruhlandt-Senge, Karin published the artcileSynthesis and structural characterization of lithium thiolates: dependence of association and aggregation on donor hapticity and ligand size and synthesis of the first trimeric lithium thiolate [Li(THF)SR]₃ and the solvent-separated ion pair [Li(12-crown-4)₂][SR] (R = 2,4,6-tBu₃C₆H₂), Formula: C15H24S, the publication is Inorganic Chemistry (1996), 35(20), 5820-5827, database is CAplus.

The synthesis and structural characterization of several Li thiolates are reported. Formation of discrete species can be achieved by careful variation of ligand size and donor hapticity, as exemplified by the monomeric formulation of Li(PMDTA)STrityl (PMDTA = N,N,N’,N”,N”-pentamethyldiethylenetriamine, Trityl = CPh₃) (1) and Li(PMDTA)STrip (2) (Trip = 2,4,6-iPr₃C₆H₂), vs. dimeric [Li(THF)₂STrityl]₂, (3) and [Li(TMEDA)STrip]₂ (4) (TMEDA = N,N,N’,N’-tetramethylethylenediamine). By control of the stoichiometry of the donor, the 1st trimeric Li thiolate [Li(THF)SMes^*]₃ (5) (Mes^* = 2,4,6-tBu₃C₆H₂), exhibiting a six-membered ring system and rare three-coordinate Li centers, is formed. In contrast, use of a crown ether gives the monomeric contact ion pair Li(12-crown-4)STrityl (6) while employing the cumbersome – SMes^* ligand produces the 1st solvent-separated Li thiolate [Li(12-crown-4)₂][SMes^*], (7). All compounds were prepared by reacting the resp. thiols with BuLi in the presence of various donor adjuncts and the target mols. were characterized using ¹H NMR and IR spectroscopy and m.p. criteria. Crystal structure data of the solid state structures are as follows. 1: At 130 K, a 12.152(3) b 15.260(3), c 14.764(5) ?, ¦Â 106.90(2)¡ã, Z = 4, monoclinic, space group P2₁/c, R = 0.064. 2: At 228 K, a 15.805(7), b 9.206(4), c 18.923(7) ?, ¦Â 99.74(3)¡ã, Z = 4, monoclinic, space group P2₁/n, R = 0.085. 3: At 213 K, a 13.141(3), b 12.381(2), c 14.664(3) ?, ¦Â 94.84(3)¡ã, Z = 2, monoclinic, space group P2₁/n, R = 0.052. 4: At 130 K, a 18.906(4), b 9.516(2), c 25.617(5) ?, ¦Â 92.75(3)¡ã, Z = 4, monoclinic, space group I2/a, R = 0.067. 5: At 213 K, a 9.991(2), b 17.934(4), c 20.314(4) ?, ¦Á 83.36(3)¡ã, ¦Â 76.74(3), ¦Ã 76.72(3)¡ã, Z = 2, triclinic, space group P1, R = 0.063. 6: At 213 K, a 10.542(2), b 12.821(3), c 18.729(4) ?, ¦Â 102.22(3)¡ã, Z = 4, monoclinic, space group P2₁/c, R = 0.086. 7: At 213 K, a 10.134(2), b 19.800(4), c 18.423(4) ?, ¦Â 93.15(3)¡ã, Z = 4, monoclinic, space group P2₁/n, R = 0.092.

Inorganic Chemistry 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, Formula: C15H24S.

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

Ruhlandt-Senge, Karin published the artcileSynthesis and Structural Characterization of Lithium Thiolates: Dependence of Association and Aggregation on Donor Hapticity and Ligand Size and Synthesis of the First Trimeric Lithium Thiolate [Li(THF)SR]₃ and the Solvent-Separated Ion Pair [Li(12-crown-4)₂][SR] (R = 2,4,6-tBu₃C₆H₂), SDS of cas: 22693-41-0, the publication is Inorganic Chemistry (1996), 35(20), 5820-5827, database is CAplus.

The synthesis and structural characterization of several Li thiolates are reported. Formation of discrete species can be achieved by careful variation of ligand size and donor hapticity, as exemplified by the monomeric formulation of Li(PMDTA)STrityl (PMDTA = N,N,N’,N”,N”-pentamethyldiethylenetriamine, Trityl = CPh₃), 1, and Li(PMDTA)STrip, 2 (Trip = 2,4,6-iPr₃C₆H₂), vs. dimeric [Li(THF)₂STrityl]₂, 3, and [Li(TMEDA)STrip]₂, 4 (TMEDA = N,N,N’,N’-tetramethylethylenediamine). By control of the stoichiometry of the donor, the 1st trimeric Li thiolate [Li(THF)SMes^*]₃, 5 (Mes^* = 2,4,6-tBu₃C₆H₂), exhibiting a six-membered ring system and rare three-coordinate Li centers, becomes available. In contrast, use of a crown ether gives the monomeric contact ion pair Li(12-crown-4)STrityl, 6, while employing the cumbersome -SMes^* ligand allows for the isolation of the 1st solvent-separated Li thiolate [Li(12-crown-4)₂][SMes^*], 7. All compounds were prepared by reacting the resp. thiols with BuLi in the presence of various donor adjuncts. The target mols. were characterized using ¹H NMR and IR spectroscopy and m.p. criteria. Crystal structure anal. was employed to determine solid state structures. Crystal data are as follows. 1: Cu K¦Á (¦Ë = 1.54178 ?) at 130 K, a 12.152(3), b 15.260(3), c 14.764(5) ?, ¦Â 106.90(2)¡ã, V = 2619.6(12) ?³, Z = 4, monoclinic, space group P2₁/c, 2526 reflections (I > 2¦Ò(I)), R = 0.064. 2: Cu K¦Á (¦Ë = 1.54178 ?) at 228 K, a 15.805(7), b 9.206(4), c 18.923(7) ?, ¦Â 99.74(3)¡ã, V = 2714(2) ?³, Z = 4, monoclinic, space group P2₁/n, 2047 reflections (I > 2¦Ò(I)), R = 0.085. 3: Mo K¦Á (¦Ë = 0.710 73 ?) at 213 K, a 13.141(3), b 12.381(2), c 14.664(3) ?, ¦Â 94.84(3)¡ã, V = 2377.3(8) ?³, Z = 2, monoclinic, space group P2₁/n, 2622 reflections (I > 2¦Ò(I)), R = 0.052. 4: Cu K¦Á (¦Ë = 1.541 ?) at 130 K, a 18.906(4), b 9.516(2), c 25.617(5) ?, ¦Â 92.75(3)¡ã, V = 4603(2) ?³, Z = 4, monoclinic, space group I2/a, 2390 reflections (I > 2¦Ò(I)), R = 0.067. 5: Mo K¦Á (¦Ë = 0.710 73 ?) at 213 K, a 9.991(2), b 17.934(4), c 20.314(4) ?, ¦Á 83.36(3), ¦Â 76.74(3), ¦Ã 76.72(3)¡ã, V = 3440.4(12) ?³, Z = 2, triclinic, space group P1, 6397 reflections (I > 2.5¦Ò(I)), R = 0.063. 6: Mo K¦Á (¦Ë = 0.71073 ?) at 213 K, a 10.542(2), b 12.821(3), c 18.729(4) ?, ¦Â 102.22(3)¡ã, V = 2474.0(9) ?³, Z = 4, monoclinic, space group P2₁/c, 4206 reflections (I > 2¦Ò(I)), R = 0.086. 7: Mo K¦Á (¦Ë = 0.71073 ?) at 213 K, a 10.134(2), b 19.800(4), c 18.423(4) ?, ¦Â 93.15(3)¡ã, V = 3691.0(13) ?³, Z = 4, monoclinic, space group P2₁/n, 4088 reflections (I > 2¦Ò(I)), R = 0.092.

Inorganic Chemistry 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, SDS of cas: 22693-41-0.

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

Pascoe, Cameron A. published the artcileMethylene analogs of neopetrosiamide as potential antimetastatic agents: solid-supported syntheses using diamino diacids for pre-stapling of peptides with multiple disulfides, COA of Formula: C20H19NO4, the publication is Organic Letters (2021), 23(23), 9216-9220, database is CAplus and MEDLINE.

Neopetrosiamide, a 28-residue peptide from Neopetrosia sp., contains three disulfide bonds and hinders mammalian tumor cell invasion. Proper connectivity of disulfide bonds is crucial for activity. Synthetic replacement of single disulfide bridges with methylene bridges gives active analogs. Pre-stapling of one ring enhances the correct formation of the remaining disulfides by reducing isomeric possibilities and possibly initiating the correct 3D fold. Cloning and expression of neopetrosiamide in E. coli affords access to the natural linear peptide.

Organic Letters 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, COA of Formula: C20H19NO4.

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

Zlatopolskiy, Boris D. published the artcileDiscovery of ¹⁸F-JK-PSMA-7, a PET probe for the detection of small PSMA-positive lesions, Name: Tetraethylammonium hydrogencarbonate, the publication is Journal of Nuclear Medicine (2019), 60(6), 817-823, database is CAplus and MEDLINE.

The aim of this study was the development of highly selective and specific PSMA probes with enhanced imaging properties, in comparison with ¹⁸FDCFPyL, ¹⁸F-PSMA-1007, and ⁶⁸Ga-PSMA-11. Methods: Eight novel ¹⁸F-labeled PSMA ligands were prepared Their cellular uptake in PSMA-pos. LNCaP C4-2 and PSMA-neg. PC-3 cells was compared with that of ¹⁸F-DCFPyL. The most promising candidates were addnl. evaluated by small-animal PET in healthy rats using PSMA-pos. peripheral ganglia as a model for small PCa lesions. PET images of the ligand with the best outcome, ¹⁸F-JKPSMA- 7, were compared with those of ¹⁸F-DCFPyL, ¹⁸F-PSMA-1007, and ⁶⁸Ga-PSMA-11 with respect to key image-quality parameters for the time frame 60-120 min. Results: Compared with ¹⁸F-DCFPyL, ¹⁸FJK- PSMA-7 demonstrated increased PSMA-specific cellular uptake. Although target-to-background ratios of ¹⁸F-DCFPyL and ¹⁸F-PSMA- 1007 were comparable, this parameter was higher for ¹⁸F-JK-PSMA- 7 and lower for ⁶⁸Ga-PSMA-11. Image acutance was significantly higher for ¹⁸F-JK-PSMA-7 and ¹⁸F-PSMA-1007 than for ¹⁸F-DCFPyL and ⁶⁸Ga-PSMA-11. Conclusion: ¹⁸F-JK-PSMA-7 is a promising candidate for high-quality visualization of small PSMApos. lesions.

Journal of Nuclear Medicine published new progress about 17351-61-0. 17351-61-0 belongs to catalysis-chemistry, auxiliary class Phase Transfer Catalyst, name is Tetraethylammonium hydrogencarbonate, and the molecular formula is C14H12O2, Name: Tetraethylammonium hydrogencarbonate.

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

Kristoffersen, Tone published the artcileMicrowave-Assisted Synthesis of Heterocycles from Aryldiazoacetates, Recommanded Product: N1,N2-Dibenzylethane-1,2-diamine, the publication is European Journal of Organic Chemistry (2020), 2020(45), 7069-7078, database is CAplus.

Herein, we describe a rapid microwave-assisted, metal-free synthesis of substituted quinoxalinones and quinoxalines using the carbene-mediated reaction between aryldiazo esters and 1,2-diamines. The reaction can encompass a range of substituents and structural variations to afford quinoxalin-2-ones in 14-80% yield and corresponding quinoxalines in good to excellent yields upon oxidation (67-96%). The approach can be employed to generate sym. and unsym. 2,3-diarylquinoxalines, bis-quinoxalines as well as novel quinoxaline-substituted diazo esters and should be a valuable addition to the heterocycle synthesis toolbox.

European Journal of Organic Chemistry published new progress about 140-28-3. 140-28-3 belongs to catalysis-chemistry, auxiliary class Benzenes, name is N1,N2-Dibenzylethane-1,2-diamine, and the molecular formula is C16H20N2, Recommanded Product: N1,N2-Dibenzylethane-1,2-diamine.

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

Elgengehi, Sara M. published the artcileAdsorption of chlorine oxyanions, as water disinfectant by-products, on graphene flakes: A quantum chemical investigation, Quality Control of 191-07-1, the publication is Surfaces and Interfaces (2022), 101601, database is CAplus.

Chlorine oxyanions namely: hypochlorite ClO^–, chlorite ClO^–₂, chlorate ClO^–₃, and perchlorate ClO^–₄, are considered to be harmful for public health since they are disinfectant byproducts and are usually found in the disinfection process of drinking water treatment plants (DWTPs). The removal of these oxyanions is, therefore, an important demand. In the current work, the adsorption of chlorine oxyanions on some graphene flakes (Gr) such as coronene (C₂₄H₁₂), circumcoronene (C₅H₁₈), and circumcircumcoronene (C₉₆H₂₄), has been theor. investigated. Favorable adequate (anion-¦Ð) interaction between the chlorine oxyanions and the electron-rich graphene flakes have been elucidated, where the stabilization largely originates from attractive electrostatic and dispersion effects. The exponential increase in the attractive electrostatic and dispersion components of the adsorption energies is found to be, in part, a consequence of a charge transfer contribution from the oxygen lone pairs of electrons of oxyanions (donors) to the low-lying ¦Ð*-orbitals of graphene flakes (acceptors). This finding means that the favorable anion-¦Ð interaction between a chlorine oxyanion and a graphene surface is not purely non-covalent.

Surfaces and Interfaces published new progress about 191-07-1. 191-07-1 belongs to catalysis-chemistry, auxiliary class Electronic Materials, name is Coronene, and the molecular formula is C24H12, Quality Control of 191-07-1.

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

Thiemann, Thies published the artcileFacile, direct reaction of benzaldehydes to 3-arylprop-2-enoic acids and 3-arylprop-2-ynoic acids in aqueous medium, Recommanded Product: (E)-3-(2,4-Dimethoxyphenyl)acrylic acid, the publication is International Journal of Organic Chemistry (2016), 6(2), 126-141, database is CAplus.

Wittig reactions of benzaldehydes, alkanals, and cycloalkanals as well as of acetophenones are carried out with alkoxycarbonyl methylidenetriphenylphosphoranes in 10 w% aqueous NaOH, where the cinnamates and alkenoates produced are hydrolyzed in situ and the corresponding acids are obtained after mostly simple extractive work-up, often without employing organic solvents. Under the same conditions, benzaldehydes are reacted with alkoxycarbonyl bromomethylidenephosphorane to produce 3-arylprop-2-ynoic acids (arylpropiolic acids).

International Journal of Organic Chemistry published new progress about 16909-09-4. 16909-09-4 belongs to catalysis-chemistry, auxiliary class Alkenyl,Carboxylic acid,Benzene,Ether, name is (E)-3-(2,4-Dimethoxyphenyl)acrylic acid, and the molecular formula is C25H34N4O2S, Recommanded Product: (E)-3-(2,4-Dimethoxyphenyl)acrylic acid.

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

Hamdy, Rania published the artcileDesign, synthesis and evaluation of new bioactive oxadiazole derivatives as anticancer agents targeting Bcl-2, Product Details of C12H16O3, the publication is International Journal of Molecular Sciences (2020), 21(23), 8980, database is CAplus and MEDLINE.

A series of 2-(1H-indol-3-yl)-5-substituted-1,3,4-oxadiazoles I [R = benzyl, 4-methylphenoxymethyl, 4-nitrophenyl, etc.] were designed, synthesized and tested in-vitro as potential pro-apoptotic Bcl-2 inhibitory anticancer agents based on previously reported compounds Synthesis of the target 1,3,4-oxadiazoles I were readily accomplished through a cyclization reaction of indole carboxylic acid hydrazide with substituted carboxylic acid derivatives RC(O)OH in the presence of phosphorus oxychloride. New compounds I showed a range of IC₅₀ values concentrated in the low micromolar range selectively in Bcl-2 pos. human cancer cell lines. The most potent candidate I [R = 4-trifluorophenyl] showed selective IC₅₀ values of 0.52-0.88¦ÌM against Bcl-2 expressing cell lines with no inhibitory effects in the Bcl-2 neg. cell line. Moreover, I [R = 4-trifluorophenyl] showed binding that was two-fold more potent than the pos. control gossypol in the Bcl-2 ELISA binding affinity assay. Mol. modeling studies helped to further rationalize anti-apoptotic Bcl-2 binding and identified compound I [R = 4-trifluorophenyl] as a candidate with drug-like properties for further investigation as a selective Bcl-2 inhibitory anticancer agent.

International Journal of Molecular Sciences published new progress about 1798-04-5. 1798-04-5 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 2-(4-(tert-Butyl)phenoxy)acetic acid, and the molecular formula is C12H16O3, Product Details of C12H16O3.

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