Tag: M.W=200-250

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

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

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 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

Klingebiel, Uwe published the artcileReactions of lithio-hexamethylcyclotrisilazane with silicon-fluoro compounds, Name: Difluorodiphenylsilane, the publication is Chemische Berichte (1977), 110(4), 1277-83, database is CAplus.

The reaction of lithiocyclotrisilazane I (R = Li with F2SiR1R2 gave 62-95% I (R = SiFR1R2, R1 = F, R2 = F, Me, Ph; R1 = Me, Ph, R2 = Ph; R1 = H, R2 = Me). Similarly, 1,3-dilithio-2,2,4,4,6,6-hexamethylcyclotrisilazane gave corresponding disubstituted derivatives Ring coupling by a Si bridge was achieved by the reaction of SiF-substituted cyclotrisilazanes with LiNHCMe3, or by the reaction of these compounds with two moles of a lithiocyclotrisilazane.

Chemische Berichte 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 C12H10F2Si, Name: Difluorodiphenylsilane.

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

Ye, Wenfa published the artcileRapid synthesis method for preparation of phenylenedioxydiacetic acid, Product Details of C10H10O6, the publication is Huaxue Shiji (2002), 24(6), 363, 378, database is CAplus.

A rapid synthetic method was used to prepare o(m,p)-phenylenedioxydiacetic acid from benzenediols and chloroacetic acid, it shortened the reaction time, raised the yield and simplified the post-treatment.

Huaxue Shiji 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 C22H38O2, Product Details of C10H10O6.

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

Larde, H. published the artcileAn observational cohort study on antimicrobial usage on dairy farms in Quebec, Canada, Recommanded Product: N1,N2-Dibenzylethane-1,2-diamine, the publication is Journal of Dairy Science (2021), 104(2), 1864-1880, database is CAplus and MEDLINE.

Quantification of antimicrobial usage (AMU) is crucial to measure the effect of intervention programs, to determine associations between usage and resistance, to compare populations, and for benchmarking purposes. The primary objective of the study was to describe quant. the AMU on Quebec dairy farms over 1 yr: (1) the total AMU, (2) the AMU per administration route (intramammary, injectable, oral, intrauterine), and (3) the AMU per antimicrobial class and according to the categorizations of Health Canada and the World Health Organization. The secondary objective was to assess the effect of several characteristics (herd size, level of milk production, and incidence rate of common infectious diseases) on AMU rate. The AMU data were obtained for 101 dairy farms randomly selected in 3 important Quebec dairy regions by collecting and recording all empty drug packaging and invoices for medicated feed (spring 2017 to spring 2018). The AMU rate was reported in number of Canadian defined course doses for cattle per 100 cow-years. The average herd size was 67 cows per farm, and 2/101 farms were certified organic Overall, an estimated mean of 537 Canadian defined course doses for cattle/100 cow-years was observed The intramammary route during lactation was the most frequently observed, followed, in decreasing order of usage, by oral route in the feed, intramammary route at drying-off, and injectable route. Oral (other than in animal feed) and intrauterine formulations were infrequently collected from the garbage cans. The 5 most frequently observed antimicrobial classes were, by decreasing order of usage, ionophores, penicillins, aminocoumarins, aminoglycosides, and polymyxins. Highest priority critically important antimicrobials as defined by the World Health Organization were mainly collected from intramammary formulations during lactation followed by injectable and drying-off intramammary formulations. The herd size was pos. associated with the total AMU rate but not with the usage rate of highest priority critically important antimicrobials. Incidence of diseases along with preventive use of antimicrobials (drying-off and medicated feed with antimicrobials) explained 48% of the variance in total AMU rate.

Journal of Dairy Science 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

Giguere, Raymond J. published the artcileIntramolecular [3 + 4] allyl cation cycloaddition: novel route to hydroazulenes, Recommanded Product: Allyldiphenylphosphine oxide, the publication is Tetrahedron Letters (1988), 29(47), 6071-4, database is CAplus.

Intramol. Hoffmann-Noyori reaction of acyclic trienol I permits direct entry to hydroazulenes II with modest diastereoselectivity. Cycloaddition precursor I is readily prepared from 1,5-pentanediol in seven steps.

Tetrahedron Letters published new progress about 4141-48-4. 4141-48-4 belongs to catalysis-chemistry, auxiliary class Aryl phosphine ligand,Mono-phosphine Ligands, name is Allyldiphenylphosphine oxide, and the molecular formula is C15H15OP, Recommanded Product: Allyldiphenylphosphine oxide.

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

Dua, Sujan S. published the artcilePreparation of tris(trimethylsilyl)methyl (“trisyl”) derivatives of silicon, Category: catalysis-chemistry, the publication is Journal of Organometallic Chemistry (1979), 178(1), 75-82, database is CAplus.

Treatment of (Me₃Si)₃CLi (TsiLi) with appropriate Si halides gave compounds (Me₃Si)₃CSiRR¹X; e.g., TsiSiCl₃, TsiSiMeCl₂, TsiSiMe₂X (X = Cl, OMe), TsiSiPh₂X (X = F, Cl, OMe), and TsiSiPhMeH. The trisyl group causes very large steric hindrance to nucleophilic displacements at the Si to which it is attached, so that (unless one or more hydride ligands are present) most of the common displacements at Si do not occur. However, halides can be reduced to hydrides by LiAlH₄, and the hydrides can be reconverted into halides in electrophilic displacements by halogens. The presence of even one hydride ligand markedly reduces the hindrance, so that, for example, TsiSiPhHI reacts with refluxing MeOH to give TsiSiPhH(OMe).

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 C12H10F2Si, Category: catalysis-chemistry.

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

Fukuda, Hiroyuki published the artcileMetal contents of liver parenchyma after percutaneous ethanol injection or radiofrequency ablation in patients with hepatocellular carcinoma before and after trientine hydrochloride therapy, Recommanded Product: N1,N1′-(Ethane-1,2-diyl)bis(ethane-1,2-diamine) dihydrochloride, the publication is Journal of Laboratory and Clinical Medicine (2004), 143(6), 333-339, database is CAplus and MEDLINE.

We administered trientine hydrochloride, a drug used in the treatment of Wilson’s disease, to patients with hepatocellular carcinoma after radical treatment with percutaneous ethanol injection or radiofrequency ablation, and examined its effect on the reduction of liver-tissue copper content. We enrolled 24 patients with 3 or fewer primary lesions of Child class A or B hepatocellular carcinoma with diameters of 3 cm or less who had undergone radical treatment with percutaneous ethanol injection or radiofrequency ablation. Trientine hydrochloride was orally administered in a single daily dose of 250 mg to 12 patients before a meal (at fasting, group 1) or at a total daily dosage of 750 mg, divided into 3 doses, to 12 patients (group 2). This study was a randomized between-groups comparative study of 12 wk’ duration. We used the particle-induced x-ray-emission method to determine liver-tissue mineral content. Urine copper and serum mineral levels were also measured, and transaminase levels were examined Liver-tissue copper content decreased significantly, to 160.1 ¦Ìg/g dry weight, after treatment, compared with the pretreatment level of 306.8 ¦Ìg/g dry weight (P <.05). We detected no significant difference in iron or zinc content before and after treatment. The copper content was significantly reduced after treatment in both groups (P <.05). The urine copper level was significantly increased after 1 wk of treatment but decreased thereafter. Serum copper levels were significantly reduced after treatment (P <.01). We detected no significant difference in transaminase level before and after treatment. Iron-deficiency anemia in 1 patient after 12 wk’ treatment was the only adverse reaction, and it was improved by the administration of an iron product. We noted no other overt adverse reactions. In patients with hepatocellular carcinoma, trientine hydrochloride therapy may significantly reduce copper content in liver tissue.

Journal of Laboratory and Clinical Medicine published new progress about 38260-01-4. 38260-01-4 belongs to catalysis-chemistry, auxiliary class Chelating Agents, name is N1,N1′-(Ethane-1,2-diyl)bis(ethane-1,2-diamine) dihydrochloride, and the molecular formula is C6H20Cl2N4, Recommanded Product: N1,N1′-(Ethane-1,2-diyl)bis(ethane-1,2-diamine) dihydrochloride.

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