Day: November 21, 2022

Hellmuth, Tina published the artcileRegioselective Catalytic Asymmetric C-Alkylation of Isoxazolinones by a Base-Free Palladacycle-Catalyzed Direct 1,4-Addition, Recommanded Product: 3-Phenylisoxazol-5(2H)-one, the publication is Angewandte Chemie, International Edition (2015), 54(9), 2788-2791, database is CAplus and MEDLINE.

Herein the first catalytic asym. alkylations of isoxazolinones I [R¹ = Me, n-Pr, Ph, PhCH₂, 2-naphthylmethyl, etc.; R² = Me, Ph, 4-O₂NC₆H₄, etc.; R¹R² = (CH₂)₄] with vinyl ketones R³C(O)CH:CH₂ (R³ = Me, Et, Ph, 4-MeOC₆H₄, PhCH₂CH₂) forming isoxazolones II with all-C-substituted quaternary stereocenter are reported. The present studies were driven by the question of how to control the regioselectivity in the competition of various nucleophilic positions. The investigation of a direct 1,4-addition uncovered that a sterically demanding palladacycle catalyst directs the reactivity in the absence of a base nearly exclusively to the nucleophilic C atom, while at the same time it allows for high enantioselectivity and TONs up to 1900.

Angewandte Chemie, International Edition published new progress about 1076-59-1. 1076-59-1 belongs to isoxazole, auxiliary class Oxazoline,Benzene,Ester, name is 3-Phenylisoxazol-5(2H)-one, and the molecular formula is C9H7NO2, Recommanded Product: 3-Phenylisoxazol-5(2H)-one.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem

Griesbeck, Axel G. published the artcilePhotocycloaddition of aromatic and aliphatic aldehydes to isoxazoles: cycloaddition reactivity and stability studies, Computed Properties of 1076-59-1, the publication is Beilstein Journal of Organic Chemistry (2011), 127-134, database is CAplus and MEDLINE.

The first photocycloadditions of aromatic and aliphatic aldehydes to methylated isoxazoles are reported. The reactions lead solely to the exo-adducts with high regio- and diastereoselectivities. E.g., photocycloaddn of 3,4,5-trimethylisoxazole with PhCHO gave 50% exo-oxetane I. Ring methylation of the isoxazole substrates is crucial for high conversions and product stability. The 6-arylated bicyclic oxetanes, e.g. I, were characterized by X-ray structure analyses and showed the highest thermal stabilities. All oxetanes formed from isoxazoles were highly acid-sensitive and also thermally unstable. Cleavage to the original substrates is dominant and the isoxazole-derived oxetanes show type T photochromism.

Beilstein Journal of Organic Chemistry published new progress about 1076-59-1. 1076-59-1 belongs to isoxazole, auxiliary class Oxazoline,Benzene,Ester, name is 3-Phenylisoxazol-5(2H)-one, and the molecular formula is C9H7NO2, Computed Properties of 1076-59-1.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem

Zhang, Na published the artcileSynergistic analgesic effect of choline and parecoxib sodium in mice and its mechanism, Synthetic Route of 198470-85-8, the publication is Nanfang Yike Daxue Xuebao (2016), 36(11), 1536-1540, database is CAplus and MEDLINE.

Objectives: To investigate the synergistic analgesic effect of choline and parecoxib sodium and to study its mechanism. Methods: In male Kunming mice with acetic acid-induced writhing, ED₅₀ of choline and parecoxib sodium was administered via the tail vein at 2 h and 30 min before modeling, resp. and their combined use was determined In saline (control) group, ED₅₀ choline (C) group, ED₅₀ parecoxib sodium (P) group, and 1/2ED₅₀ choline and parecoxib sodium (1/2[C+P]) group, blood samples were collected from the eyeball 10 min after i.p. administration of acetic acid to detect the levels of IL-1, TNF-α, PGE₂, NF-κB, and I-κB levels using ELISA kits. Results: In the acetic acid-induced writhing model, the ED₅₀ of choline and parecoxib sodium was 8.64 and 6.33 mg/kg, and when combined, their ED₅₀ was 2.13 and 1.56 mg/kg, resp. The isobolograms of parecoxib sodium and choline showed that the measured ED₅₀ of the two drugs combined was below the theor. ED₅₀ value (P < 0.05) with a combination index (CI) of < 0.9. Compared with the control group, C group, P group, and 1/2 (C+P) group all showed significantly lowered IL-1 and TNF-α levels (P < 0.05), especially in 1/2 (C+P) group (P < 0.05). PGE₂ level was significantly lower in P group and 1/2 (C+P) group compared with the control group (P < 0.05). The level od NF-κB and I-κB was significantly lowered in C, P, and 1/2 (C+P) groups (P < 0.05), and the reduction was the most obvious in 1/2 (C+P) group (P < 0.05). Conclusions: Choline and parecoxib sodium has a synergistic analgesic effect, and their interactions may involve the in vivo expression of NF-κB.

Nanfang Yike Daxue Xuebao published new progress about 198470-85-8. 198470-85-8 belongs to isoxazole, auxiliary class Immunology/Inflammation,COX, name is Sodium ((4-(5-methyl-3-phenylisoxazol-4-yl)phenyl)sulfonyl)(propionyl)amide, and the molecular formula is C15H14BNO4S, Synthetic Route of 198470-85-8.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem

Song, Hong published the artcileSynthesis and herbicidal activity of novel 4-acyl-2,5-disubstituted-3-hydroxypyrazoles and 4-arylcarbonyl-3-substituted-isoxazol-5-ones, Computed Properties of 1076-59-1, the publication is Journal of Heterocyclic Chemistry (2013), 50(6), 1381-1385, database is CAplus.

Novel 2,5-disubstituted 4-acyl-3-hydroxypyrazoles I and II (R = Me, R¹ = Ph; R = Me, R¹ = 4-ClC₆H₄; R = Me, R¹ = 4-FC₆H₄; R = R¹ = Ph) and 4-aroylisoxazol-5-ones III (R = Me, R¹ = Ph, 2-ClC₆H₄, 3-ClC₆H₄, 4-ClC₆H₄, 2-FC₆H₄, 4-FC₆H₄, 4-MeC₆H₄; R = Ph, R¹ = 2-ClC₆H₄, 4FC₆H₄) were synthesized by Schotten-Baumann reaction of acyl chlorides with appropriate 2,4-dihydropyrazol-3-ones and 4H-isoxazol-5-ones, resp., followed by Fries rearrangement in the presence of Ca(OH)₂ and CaO as the catalyst. ¹H NMR indicated that I and II existed in enol forms and III in keto configurations. Preliminary bioassays showed that some of the title compounds I–III exhibited moderate to good herbicidal activities against Brassica campestris at 100 mg/L. Isoxazoles III showed better herbicidal activity against B. campestris than pyrazoles I and II at 100 mg/L. Moreover, most of the isoxazoles displayed higher herbicidal activity against B. campestris than Echinochloa crus-galli. However, these compounds showed weak herbicidal activities at 10 mg/L.

Journal of Heterocyclic Chemistry published new progress about 1076-59-1. 1076-59-1 belongs to isoxazole, auxiliary class Oxazoline,Benzene,Ester, name is 3-Phenylisoxazol-5(2H)-one, and the molecular formula is C8H7NaO4S, Computed Properties of 1076-59-1.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem

Wei, Qiang published the artcileSmall-Molecule Emitters with High Quantum Efficiency: Mechanisms, Structures, and Applications in OLED Devices, Related Products of isoxazole, the publication is Advanced Optical Materials (2018), 6(20), n/a, database is CAplus.

A review. Organic emitters play a vital role in determining the overall performance of organic light emitting diode (OLED) devices. Traditional fluorescent emitters can only achieve external quantum efficiency (EQE) of 5%, far below expectation; therefore many efforts have been spent on increasing the EQE of OLEDs. Phosphorescence, thermally activated delayed fluorescence, triplet-triplet annihilation, and hybridized local and charge transfer are the most widely applied approaches to harvest the 75% triplet excitons for luminescence. As for selecting or designing suitable emitters for practical applications, it is strongly demanded to have an overall view about emitters of high exciton utilizing efficiency (EUE) from mol. level, i.e., the four common approaches mentioned above and some latest ones of the doublet, singlet fission, triplet-polar annihilation, and rotationally accessed spin state inversion, and also from the aggregated state such as aggregation-induced emission. In this review, the current progress of highly efficient emitters is presented, covering the chem. structures, the high-EUE mechanisms in mol. level and aggregated state, and their applications in OLED devices. This review hopefully will illustrate highly efficient electroluminescent materials and their mechanisms, but more importantly, provide helpful information on how to design or select suitable emitters for specific OLED devices.

Advanced Optical Materials published new progress about 1313391-57-9. 1313391-57-9 belongs to isoxazole, auxiliary class OLED Materials,Red Fluorescence Dopants, name is 3-(4,6-Diphenyl-1,3,5-triazin-2-yl)-9-phenyl-9H-carbazole, and the molecular formula is C14H12N2S, Related Products of isoxazole.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem

Nowrouzi, Najmeh published the artcile4-(N,N-Dimethylamino)pyridinium acetate as a recyclable catalyst for the synthesis of 5-substituted-1H-tetrazoles, Product Details of C8H5F3N4, the publication is Tetrahedron Letters (2015), 56(5), 739-742, database is CAplus.

An efficient method for the synthesis of 5-substituted-1H-tetrazoles through the reaction of nitriles with sodium azide using 4-(N,N-dimethylamino)pyridinium acetate as a recyclable catalyst with ionic liquid character is described. The reactions proceed well at 100 °C and provide the corresponding tetrazoles in good to excellent yields. This method has the advantage of easy work-up of the product without the requirement of HCl. Mono [3+2] cycloaddition products were obtained from dicyanides via this method.

Tetrahedron Letters published new progress about 2251-79-8. 2251-79-8 belongs to isoxazole, auxiliary class Trifluoromethyl,Fluoride,Benzene, name is 5-(4-(Trifluoromethyl)phenyl)-1H-tetrazole, and the molecular formula is C8H5F3N4, Product Details of C8H5F3N4.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem

Nowrouzi, Najmeh published the artcilePiperazinium Dihydrogen Sulfate: An Acidic Ionic Liquid for the [3+2] Cycloaddition Reaction of Sodium Azide with Organic Nitriles, Product Details of C8H5F3N4, the publication is Letters in Organic Chemistry (2016), 13(2), 113-119, database is CAplus.

Background: Tetrazoles are imperative nitrogen rich heterocyclic compounds with a wide range of applications in the field of organic synthesis, coordination chem., material sciences, and medicinal chem. A most common approach for the synthesis of 5-substituted-1H-tetrazoles is achieved by [3+2] cycloaddition reaction of azides to nitriles. A new acidic ionic liquid is introduced as a catalyst to promote the mentioned reaction. Methods: Piperazinium dihydrogen sulfate:as a new acidic ionic compound was obtained by treatment of piperazine with sulfuric acid, which is further was applied as a catalyst for the [3+2] cycloaddition reaction of azides to organic nitriles. Results: The [3+2] cycloaddition reaction of sodium azide with structurally different organic nitriles using only 1.5 mol% of the piperazinium dihydrogen sulfate proceeded well at 100°C and 5-substituted-1H-tetrazoles were prepared in good to excellent yields. Herein, piperazinium dihydrogen sulfate has a dual role of catalyst and reaction medium, which circumvents the use of any organic solvent. The catalyst is also recyclable. This method is particularly suitable for benzonitriles carrying deactivating groups which furnished the corresponding products in excellent yields. By this method, mono [3+2] cycloaddition product of dicyanides was obtained. Conclusion: In conclusion, piperazinium dihydrogen sulfate as a new acidic ionic compound was applied to promote synthesis of 5-substituted-1H-tetrazoles through [3+2] cycloaddition reaction of organic nitriles with sodium azide. This new ionic compound can be easily separated from the reaction mixture which resulted to a simple work-up of the products.

Letters in Organic Chemistry published new progress about 2251-79-8. 2251-79-8 belongs to isoxazole, auxiliary class Trifluoromethyl,Fluoride,Benzene, name is 5-(4-(Trifluoromethyl)phenyl)-1H-tetrazole, and the molecular formula is C8H5F3N4, Product Details of C8H5F3N4.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem

Khalili, Dariush published the artcileCopper(I) Complex of Dihydro Bis(2-Mercapto Benzimidazolyl) Borate as an Efficient Homogeneous Catalyst for the Synthesis of 2H-Indazoles and 5-Substituted 1H-Tetrazoles, Computed Properties of 2251-79-8, the publication is ChemistrySelect (2021), 6(4), 746-753, database is CAplus.

Catalytic activity of a series of copper(I) complexes containing dihydrobis(2-mercapto-benzimidazolyl) borate (Bb), and phosphine co-ligands was investigated in the synthesis of N-heterocycle compounds including 2H-indazoles and 5-substituted 1H-tetrazoles. The copper(I) complex containing tricyclohexylphosphine co-ligand, [Cu(Bb)(PCy₃)], displayed the highest catalytic activities for the formation of 2H-indazoles and 1H-tetrazoles. Apart from the nontoxicity and strong σ-donating ability of the introduced ligands, the introduced catalyst required easy handling processes. The catalytic reactions were successfully performed at low catalyst loadings in either PEG-200 or DMF and in relatively short reaction times. The diversity of these reactions was also explored with 20 and 12 examples. Finally, the above reported catalytic system was amenable to large-scale production of these N-heterocycle compounds

ChemistrySelect published new progress about 2251-79-8. 2251-79-8 belongs to isoxazole, auxiliary class Trifluoromethyl,Fluoride,Benzene, name is 5-(4-(Trifluoromethyl)phenyl)-1H-tetrazole, and the molecular formula is C8H5F3N4, Computed Properties of 2251-79-8.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem

Elguero, Jose published the artcileStudies on the azole series. Part 101. Determination by fluorine-19 NMR spectroscopy of the σ₁ and σ⁰_R parameters of N-substituted azoles, Quality Control of 57103-14-7, the publication is Journal of Chemical Research, Synopses (1981), 364-5, database is CAplus.

N-(m– And p-Fluorophenyl)-substituted heterocyclic compounds, including pyrroles and triazoles, were prepared and their ¹⁹F NMR were observed The ¹⁹F chem. shifts were used to calculate the σ_I and σ⁰_R substituent constants using equations derived empirically from substituted fluorobenzenes with known substituent constants

Journal of Chemical Research, Synopses published new progress about 57103-14-7. 57103-14-7 belongs to isoxazole, auxiliary class Fused Tricycles,Carbazoles, name is 9-(4-Fluorophenyl)-9H-carbazole, and the molecular formula is C18H12FN, Quality Control of 57103-14-7.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem

Jana, Sripati published the artcileMulti C-H Functionalization Reactions of Carbazole Heterocycles via Gold-Catalyzed Carbene Transfer Reactions, Safety of 9-(4-Fluorophenyl)-9H-carbazole, the publication is Chemistry – A European Journal (2021), 27(8), 2628-2632, database is CAplus and MEDLINE.

Multiple C-H functionalization reaction of carbazole heterocycles with diazoalkanes are described. Gold catalysts play a distinct role in enabling a multiple C-H functionalization reaction to introduce up to six carbene fragments onto mols. containing multiple carbazole units or to link multiple carbazole units into a single mol. A one-pot stepwise approach enables the introduction of two different carbene fragments to allow orthogonal deprotection and straightforward derivatization.

Chemistry – A European Journal published new progress about 57103-14-7. 57103-14-7 belongs to isoxazole, auxiliary class Fused Tricycles,Carbazoles, name is 9-(4-Fluorophenyl)-9H-carbazole, and the molecular formula is C18H12FN, Safety of 9-(4-Fluorophenyl)-9H-carbazole.

Referemce:
https://en.wikipedia.org/wiki/Isoxazole,
Isoxazole | C3H3NO – PubChem