Month: December 2022

Tan, Choon-Hong published the artcileStereochemical assignment of the C21-C38 portion of the desertomycin/oasomycin class of natural products by using universal NMR databases: Proof, Quality Control of 99438-28-5, the publication is Angewandte Chemie, International Edition (2000), 39(23), 4282-4284, database is CAplus and MEDLINE.

We have predicted the stereochem. of the C21-C38 portion of the desertomycin/oasomycin class of natural products and have proven the predicted stereochem. by a stereoselective synthesis of the C21-C38 degradation product.

Angewandte Chemie, International Edition published new progress about 99438-28-5. 99438-28-5 belongs to ethers-buliding-blocks, auxiliary class Chiral,Aliphatic cyclic hydrocarbon, name is (+)-B-Methoxydiisopinocampheylborane, and the molecular formula is C5H4N4, Quality Control of 99438-28-5.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Denmark, Scott E. published the artcileTotal synthesis of (+)-papulacandin D, Name: (+)-B-Methoxydiisopinocampheylborane, the publication is Tetrahedron (2010), 66(26), 4745-4759, database is CAplus and MEDLINE.

A total synthesis of (+)-papulacandin D (I) was achieved in 31 steps, in a 9.2% overall yield from com. available materials. The synthetic strategy divided the mol. into two nearly equal sized subunits, i.e. the spirocyclic C-arylglycopyranoside and the polyunsaturated fatty acid side-chain. The C-arylglycopyranoside was prepared in 11 steps in a 30% overall yield from triacetoxyglucal. The fatty acid side-chain was also prepared in 11 steps in a 30% overall yield from geraniol. The key strategic transformations in the synthesis were a palladium-catalyzed organosilanolate-based cross-coupling reaction of a dimethylglucal-silanol with an electron-rich and sterically hindered aromatic iodide and a Lewis-base catalyzed enantioselective allylation reaction of a dienal and allyltrichlorosilane. A critical element in the successful execution of the synthesis was the development of a suitable protecting group strategy that satisfied a number of stringent criteria.

Tetrahedron published new progress about 99438-28-5. 99438-28-5 belongs to ethers-buliding-blocks, auxiliary class Chiral,Aliphatic cyclic hydrocarbon, name is (+)-B-Methoxydiisopinocampheylborane, and the molecular formula is C21H37BO, Name: (+)-B-Methoxydiisopinocampheylborane.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Chichibabin, A. E. published the artcileAction of aldehydes on α-aminopyridine and on α-dimethylaminopyridine, Related Products of ethers-buliding-blocks, the publication is Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen (1931), 2839-42, database is CAplus.

In the action of HCHO on α-aminopyridine (1), 2 reactions take place simultaneously, condensation to a dipyridyl derivative and methylation of the amino group, the end product being p,p’-tetra methyldiaminodipyridylmethane (C. A. 24, 1642). It seemed of interest to study the behavior of other aldehydes toward I under these conditions. With aromatic aldehydes in HCO₂H there is no condensation, only a reaction analogous to the above methylation but differing from it in that only 1 H atom of the amino group seems to be replaced by the aromatic residue because the primarily formed Schiff base is at once reduced; secondary amines can be obtained in excellent yield by this method. The o-substituted derivatives of BzH studied (o-NO₂, o-HO) do not react with I under these conditions. BzH, heated with α-C₅H₄NNMe₂ (II) and ZnCL₂, reacts like BzH with PhNMe₂, giving phenylbis(α-dimethylaminopyridyl)methane (III), which is oxidized by PbO₂ in acid solution to the carbinol (IV). α-Benzylaminopyridine, m. 94°, is obtained in 90% yield from I in anhydrous HCO₂H refluxed with BzH. α-(p-Methoxybenzylamino)pyridine, from I and anisaldehyde (80-5% yield), m. 128°. α-(3,4-Methylenedioxybenzylamino)-pyridine (70%), m. 99-100°. α-Formylaminopyridine, from equimol. amounts of I and anhydrous HCO₂H carefully heated in a Claisen flask until the formation of water ceased, b₁₅161-2°, m. 71°. III (6 g. from 10 g. II), m. 130-1°, soluble in H₂SO₄ without color. IV, yellowish, m. 123-4°, soluble in concentrated H₂SO₄ with blood-red and in HCl with deep red color, water destroying the color, which, however, is restored by concentrated acids, although the simple salts cannot be obtained in colored form.

Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen published new progress about 52818-63-0. 52818-63-0 belongs to ethers-buliding-blocks, auxiliary class Pyridine,Amine,Benzene,Ether, name is N-(4-Methoxybenzyl)pyridin-2-amine, and the molecular formula is C13H14N2O, Related Products of ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Kulhanek, Jiri published the artcileQuadrupolar fluorophores with tetrafluorobenzene central electron acceptor, COA of Formula: C11H17BO3S, the publication is Journal of Fluorine Chemistry (2021), 109735, database is CAplus.

Seven novel quadrupolar chromophores based on 1,2,4,5-tetrafluorobenzene (TFB) central electron acceptor unit and methoxythiophene peripheral donor were synthesized and described. Fundamental structure-property relationships were elucidated via thermal, electrochem. and optical measurements. These revealed that the properties are mostly affected by the used π-linker. Variation of the π-linker resulted in tuning of the HOMO-LUMO gap. The LUMO clearly reflects planarity, polarizability and electronic transparency of the utilized π-linker. The absorption maxima of target chromophores were found within the range of 346-412 nm and the emission maxima of emissive derivatives were found within the range of 411-499 nm. Novel TFBs were compared with TFBs previously described in the literature. The exptl. data are further corroborated by theor. calculations

Journal of Fluorine Chemistry published new progress about 596819-12-4. 596819-12-4 belongs to ethers-buliding-blocks, auxiliary class Thiophene,Boronic acid and ester,Ether,Boronate Esters,Boronic acid and ester, name is 2-(5-Methoxythiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, and the molecular formula is C11H17BO3S, COA of Formula: C11H17BO3S.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Hlouskova, Zuzana published the artcileStructural elaboration of dicyanopyrazine: towards push-pull molecules with tailored photoredox activity, COA of Formula: C11H17BO3S, the publication is RSC Advances (2019), 9(41), 23797-23809, database is CAplus and MEDLINE.

As an extension of the successful dicyanopyrazine photoredox catalysts, a series of X-shaped push-pull mols. with a systematically altered structure I [R¹ = SMe, CN, 2-thienyl, etc.; R² = OMe, CN, 2-thienylsulfanyl, etc.; R³ = SMe, CN, 2-thienylsulfanyl, etc.] were designed and facilely synthesized and their structure-property relationship was elucidated in detail via exptl. as well as theor. calculations Dicyanopyrazines I were proven to be powerful photoredox catalysts with a push-pull arrangement that allowed facile property tuning by interchanging a particular part of the D-π-A system. Changing the mutual position of the cyano acceptors and the methoxy, methylthio and thienyl donors as well as modifying the linker allowed wide tuning of the fundamental properties of the catalysts. Contrary to the currently available organic photoredox catalysts, a series of catalysts based on a pyrazine heterocyclic scaffold with easy synthesis and further modification, diverse photoredox characteristics and wide application potential across modern photoredox transformations was provided . The photoredox catalytic activities of the target catalysts were examined in a benchmark cross-dehydrogenative coupling and novel and challenging annulation reactions.

RSC Advances published new progress about 596819-12-4. 596819-12-4 belongs to ethers-buliding-blocks, auxiliary class Thiophene,Boronic acid and ester,Ether,Boronate Esters,Boronic acid and ester, name is 2-(5-Methoxythiophen-2-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, and the molecular formula is C11H17BO3S, COA of Formula: C11H17BO3S.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Elstner, R. published the artcileStudies on the effect of inhibitors in ammonia etching solutions on the depth and pattern in copper etching, Category: ethers-buliding-blocks, the publication is Metalloberflaeche (1982), 36(10), 468-78, database is CAplus.

The effects of inhibitors on the etching of Cu for printed circuits by ammoniacal solutions of Na chlorite and CuCl₂ were studied. The etch rates and elec. conductivity of the different solutions are given. The effects of Cu(I) ions are discussed. The optimum etching conditions are described.

Metalloberflaeche published new progress about 14807-75-1. 14807-75-1 belongs to ethers-buliding-blocks, auxiliary class Salt,Thiourea,Amine,Aliphatic hydrocarbon chain, name is Formamidine disulfide dihydrochloride, and the molecular formula is C2H8Cl2N4S2, Category: ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Oster, Alexander published the artcileBicyclic Substituted Hydroxyphenylmethanone Type Inhibitors of 17 β-Hydroxysteroid Dehydrogenase Type 1 (17 β-HSD1): The Role of the Bicyclic Moiety, Related Products of ethers-buliding-blocks, the publication is ChemMedChem (2011), 6(3), 476-487, database is CAplus and MEDLINE.

An attractive target that has still to be explored for the treatment of estrogen-dependent diseases, such as breast cancer and endometriosis, is the enzyme responsible for the last step in the biosynthesis of estradiol (E2): 17β-hydroxysteroid dehydrogenase type 1 (17β-HSD1). It catalyzes the reduction of the weakly active estrone (E1) into E2, which is the most potent estrogen in humans. Inhibition of 17β-HSD1 lowers intracellular E2 concentrations and thus presents a therapeutic target for estrogen-dependent pathologies. Recently, we reported a new class of highly active and selective 17β-HSD1 inhibitors: bicyclic substituted hydroxyphenylmethanones. Here, further structural variations on the bicyclic moiety are described, especially focusing on the exchange of its hydroxy function. Twenty-nine novel inhibitors were synthesized and evaluated for 17β-HSD1 inhibition in a cell-free and cellular assay, for selectivity toward 17βHSD2 and estrogen receptors (ER) alpha and beta, as well as for metabolic stability. The best compound (I) exhibited IC₅₀ values of 12 nM (cell-free assay) and 78 nM (cellular assay), high selectivity for 17β-HSD1, and reasonable metabolic stability. A mol. docking study provided insight into the protein-ligand interactions of this compound with 17β-HSD1.

ChemMedChem published new progress about 845551-45-3. 845551-45-3 belongs to ethers-buliding-blocks, auxiliary class Chloride,Boronic acid and ester,Benzene,Ether,Boronic Acids,Boronic Acids,Boronic acid and ester,, name is (3-((2-Chlorobenzyl)oxy)phenyl)boronic acid, and the molecular formula is C13H12BClO3, Related Products of ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Woods, Thomas S. published the artcileCleavage of sulfur-sulfur bonds with sodium hydrogen selenide, Computed Properties of 14807-75-1, the publication is Journal of Organic Chemistry (1974), 39(25), 3716-20, database is CAplus.

Sodium hydrogen selenide is shown to be an effective reagent for reduction of alkyl, aryl, aralkyl, and functionally substituted disulfides to thiols under mild conditions in protic solvents. Two-electron transfer from the hydrogen selenide anion, which promotes the cleavage of the S-S bond with concomitant production of elemental selenium, is found to occur only in a narrow pH range. Organic thiosulfates (Bunte salts) also give thiols through the intermediacy of the corresponding disulfide on reaction with sodium hydrogen selenide.

Journal of Organic Chemistry published new progress about 14807-75-1. 14807-75-1 belongs to ethers-buliding-blocks, auxiliary class Salt,Thiourea,Amine,Aliphatic hydrocarbon chain, name is Formamidine disulfide dihydrochloride, and the molecular formula is C4H6BrN3, Computed Properties of 14807-75-1.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Reinisch, Jens published the artcilePredicting Flash Points of Pure Compounds and Mixtures with COSMO-RS, Related Products of ethers-buliding-blocks, the publication is Industrial & Engineering Chemistry Research (2015), 54(51), 12974-12980, database is CAplus.

Flash point (FP) is an important parameter to assess chem. compound safety. Many empirical approaches have been developed to predict FP based on mol. structure, sometimes involving a large number of descriptors and resulting in class-specific equations. This work demonstrated that a satisfying, rather general prediction of saturation pressure at the FP can be achieved using only mol. surface area. This relation in conjunction with any exptl. or computational method to calculate temperature-dependent vapor pressures allows for the FP predictions. In a second step, chem. mixture FP were calculated using COSMO-RS activity coefficients Using the proposed method, FP were calculated without needing data typically generated in experiments (normal b.p., combustion enthalpy), although exptl. pure-compound FP and vapor pressure data can still be used to increase prediction quality.

Industrial & Engineering Chemistry Research published new progress about 1589-47-5. 1589-47-5 belongs to ethers-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Alcohol,Ether, name is 2-Methoxypropan-1-ol, and the molecular formula is C4H10O2, Related Products of ethers-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem

Saprykin, L. V. published the artcileEvolution of volatile substances during thermal degradation of rice hull organic components. 1. Thermolysis with inorganic catalytic additives, Formula: C10H14O, the publication is Koksnes Kimija (1990), 8-14, database is CAplus.

A comparison of the catalytic effect of NaCl, KCl, CaCl₂, MgCl₂, CsBr, and LiCl on thermolysis of rice hulls for Si showed that LiCl exerted the strongest effect. LiCl significantly changed the composition of the thermolysis products by promoting cleavage of C-C and ether bonds. NH₄Cl catalyzed low-temperature dehydration and secondary resinification reactions of the thermolysis products. Significant amounts of SiO₂ contained in the rice hull and in its hydrolytic lignin leveled the catalytic effect of LiCl. The thermolysis products included 2-methyldioxolane, mesityl oxide, 2-isopropylanisole, PhOH, guaiacol, 2-ethylphenol, veratrole, furfural, formal, coumaran, ethylpyrocatechol, and Me₂CO.

Koksnes Kimija published new progress about 2944-47-0. 2944-47-0 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether, name is 2-Isopropylanisole, and the molecular formula is C10H14O, Formula: C10H14O.

Referemce:
https://en.wikipedia.org/wiki/Ether,
Ether | (C2H5)2O – PubChem