Month: December 2022

Nguyen, Suong T. published the artcileLight-Driven Depolymerization of Native Lignin Enabled by Proton-Coupled Electron Transfer, Related Products of catalysis-chemistry, the publication is ACS Catalysis (2020), 10(1), 800-805, database is CAplus.

Here, we report a catalytic, light-driven method for the redox-neutral depolymerization of native lignin biomass at ambient temperature This transformation proceeds via a proton-coupled electron-transfer (PCET) activation of an alc. O-H bond to generate a key alkoxy radical intermediate, which then facilitates the ¦Â-scission of a vicinal C-C bond. Notably, this single-step depolymerization is driven solely by visible-light irradiation, requires no stoichiometric chem. reagents, and produces no stoichiometric waste. This method exhibits good efficiency and excellent selectivity for the activation and fragmentation of the ¦Â-O-4 linkage in the polymer backbone, even in the presence of numerous other PCET-active functional groups. The feasibility of this protocol in enabling the cleavage of the ¦Â-1 linkage in model lignin dimers was also demonstrated. These results provide further evidence that visible-light photocatalysis can serve as a viable method for the direct conversion of lignin biomass into valuable arene feedstocks.

ACS Catalysis 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, Related Products of catalysis-chemistry.

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

Oku, Naoki published the artcilePhotoassisted Cross-Coupling Reaction of ¦Á-Chlorocarbonyl Compounds with Arylboronic Acids, Formula: C14H14, the publication is Organic Letters (2022), 24(8), 1616-1619, database is CAplus and MEDLINE.

A Suzuki-Miyaura cross-coupling reaction of ¦Á-chloroacetates or ¦Á-chloroacetamides with arylboronic acids was made possible by visible-light irradiation This reaction provides a useful method for the synthesis of ¦Á-arylacetates and ¦Á-arylacetamides from chlorides under mild reaction conditions. An indole-3-acetic acid derivative that is the key intermediate of the plant hormone auxin was synthesized from 1-Boc-indole by two steps combining Ir(I)-catalyzed C-H borylation and Pd(0)-catalyzed cross-coupling reaction.

Organic Letters published new progress about 613-33-2. 613-33-2 belongs to catalysis-chemistry, auxiliary class Benzene, name is 4,4′-Dimethyldiphenyl, and the molecular formula is C14H14, Formula: C14H14.

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

Ohshita, Joji published the artcileSynthesis of Group 14 Dipyridinometalloles with Enhanced Electron-Deficient Properties and Solid-State Phosphorescence, Application of Difluorodiphenylsilane, the publication is Organometallics (2014), 33(2), 517-521, database is CAplus.

Si- and Ge-bridged bipyridyls were prepared, and their optical and electrochem. properties were studied. They exhibited enhanced electron deficiency and phosphorescence properties in comparison to parent bipyridyl. The single-crystal structure of a dipyridinosilole and results of DFT calculations on models are also described.

Organometallics 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, Application of Difluorodiphenylsilane.

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

Kubota, L. T. published the artcileElectrochemical investigation of some aromatic redox mediators immobilized on titanium phosphate, Name: 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate, the publication is Quimica Analitica (Barcelona) (2000), 19(Supl. 1), 15-27, database is CAplus.

Some phenazines, phenoxazines, and phenothiazines as well as riboflavin were immobilized on amorphous titanium phosphate (TP) by adsorption from aqueous solutions The immobilized organic redox compounds revealed a reasonable electron transfer rate and with a formal potential (E¡ã’) at pH 7.0 more pos. than that observed for their corresponding aqueous soluble counterparts. This shift in the E¡ã’ was partly assigned to the acidity of TP. The E¡ã’ of the immobilized redox compound remained virtually constant with a variation of the solution pH between 1 and 8 and was attributed to the protection effect of the matrix. Attenuated total reflectance IR spectroscopy (ATRIS) of methylene blue and riboflavin adsorbed onto TP deposited on ZnSe-prism was also used to shed further light on the interaction between these aromatic redox compounds and TP, as ATRIS is sensitive to the mode of adsorption of mols. on surfaces. Four of the immobilized compounds (Nile blue, methylene blue, toluidine blue O, methylene violet) were shown to be efficient as electron transfer mediators to electrocatalytically oxidize NADH in aqueous solution at pH 7.0. The kinetic parameters such as apparent Michaelis-Menten constant were obtained for these four immobilized mediators.

Quimica Analitica (Barcelona) 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, Name: 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate.

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

Gade, Swapna M. published the artcileSynthesis of glycidol from glycerol and dimethyl carbonate using ionic liquid as a catalyst, Synthetic Route of 17351-62-1, the publication is Catalysis Communications (2012), 184-188, database is CAplus.

Transesterification of di-Me carbonate with glycerol has been investigated using various ionic liquids as catalysts. Synthesis of glycidol with high selectivity (78%) has been achieved using tetramethylammonium hydroxide ([TMA][OH]) as a catalyst at 80 ¡ãC. Effect of various reaction conditions on the activity and selectivity was investigated and catalyst concentration had a significant influence on conversion as well as selectivity to glycidol. Activity as well as selectivity of the catalyst decreased significantly with increase in moisture content. Recycle experiment indicated slight drop in glycerol conversion and selectivity to glycidol because of dilution of reaction mixture and also the presence of products from the initial experiment

Catalysis Communications published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Synthetic Route of 17351-62-1.

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

Ispizua-Rodriguez, Xanath published the artcileDirect Synthesis of Tri-/Difluoromethyl Ketones from Carboxylic Acids by Cross-Coupling with Acyloxyphosphonium Ions, COA of Formula: C8H7NO4, the publication is Chemistry – A European Journal (2021), 27(64), 15908-15913, database is CAplus and MEDLINE.

A simple and straightforward approach to the synthesis of trifluoromethyl and difluoromethyl ketones RC(O)CF₃ [R = naphth-2-yl, benzyl, (Z)-cycloundecen-2-yl, etc.] and RC(O)CF₂H from widely available carboxylic acids RC(O)OH is disclosed. The transformation utilizes an acyloxyphosphonium ion as the active electrophile, conveniently generated in situ from the carboxylic acid substrate by using commodity chems. The utility of the reaction system is exemplified by its chemoselectivity, with tolerance to a variety of important functional groups. The late-stage functionalization of carboxylic acid active pharmaceutical ingredients and pharmaceutically relevant compounds is also discussed.

Chemistry – A European Journal 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

Eibl, Christoph published the artcileThe 3,7-diazabicyclo[3.3.1]nonane scaffold for subtype selective nicotinic acetylcholine receptor ligands. Part 2: Carboxamide derivatives with different spacer motifs, Product Details of C9H7NO4, the publication is Bioorganic & Medicinal Chemistry (2013), 21(23), 7309-7329, database is CAplus and MEDLINE.

3,7-Diazabicyclo[3.3.1]nonane (bispidine) based nicotinic acetylcholine receptor (nAChR) ligands, e.g., I, have been synthesized and evaluated for nAChRs interaction. Diverse spacer motifs were incorporated between the hydrogen bond acceptor (HBA) part and a variety of substituted (hetero)aryl moieties. Bispidine carboxamides bearing spacer motifs often showed high affinity in the low nanomolar range and selectivity for the ¦Á4¦Â2^* nAChR. Compound I and the other two tested compounds with K_i values of about 1 nM displayed the highest affinities for ¦Á4¦Â2* nAChR. All evaluated compounds are partial agonists or antagonists at ¦Á4¦Â2*, with reduced or no effects on ¦Á3¦Â4* with the exception of compound I (agonist), and reduced or no effect at ¦Á7 and muscle subtypes.

Bioorganic & Medicinal 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, Product Details of C9H7NO4.

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

Duhamel, Thomas published the artcileCooperative iodine and photoredox catalysis for direct oxidative lactonization of carboxylic acids, Quality Control of 1949-41-3, the publication is Chemical Communications (Cambridge, United Kingdom) (2019), 55(7), 933-936, database is CAplus and MEDLINE.

A new method for the formation of ¦Ã- and ¦Ä-lactones from carboxylic acids through direct conversion of benzylic C-H to C-O bonds was described. The reaction was conveniently induced by visible light and relied on a mild cooperative catalysis by the combination of mol. iodine and an organic dye.

Chemical Communications (Cambridge, United Kingdom) published new progress about 1949-41-3. 1949-41-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene, name is 2-Methyl-4-phenylbutanoic acid, and the molecular formula is C11H14O2, Quality Control of 1949-41-3.

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

Ge, Weizhi published the artcileSynthesis and structure-activity relationship studies of parthenolide derivatives as potential anti-triple negative breast cancer agents, SDS of cas: 16909-09-4, the publication is European Journal of Medicinal Chemistry (2019), 445-469, database is CAplus and MEDLINE.

Triple-neg. breast cancer (TNBC) is the most aggressive cancers with a high recurrence rate and rapidly acquired drug resistance among various breast cancer subtypes. There is no specific drug for treatment of TNBC. Discovery of therapeutic agents with unique modes of actions is urgently needed. In this study, a series of seventy parthenolide derivatives was designed, synthesized, and evaluated for their anti-TNBC activities. Compound I exhibited the most potent activity against different breast cancer cells with IC₅₀ values ranging from 0.20 ¦ÌM to 0.27 ¦ÌM, which demonstrated 11.6- to 18.6-fold improvement comparing to that of the parent compound parthenolide with IC₅₀ values of 2.68-4.63 ¦ÌM. It is worth to note that I was more active than the pos. control drug ADR. Moreover, compound I could induce apoptosis of SUM-159 cells through mitochondria pathway and cause G1 phase arrest of SUM-159 cells. These findings indicate that compound I deserves further studies as a lead compound for ultimate discovery of effective anti-TNBC drug.

European Journal of Medicinal 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 C11H12O4, SDS of cas: 16909-09-4.

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

Xia, Yiran published the artcileFmoc-protected amino acids as luminescent and circularly polarized luminescence materials based on charge transfer interaction, Synthetic Route of 71989-31-6, the publication is Chinese Chemical Letters (2022), 33(11), 4918-4923, database is CAplus.

Fluorenylmethyloxycarbonyl (Fmoc)-protected amino acids are effective building blocks in self-assembled architectures at hierarchical levels, which however show limited luminescent properties and chiroptical activities. Here we introduce a charge-transfer strategy to build two-component luminescent materials with emerged circularly polarized luminescence properties. A library of Fmoc-amino acids was built, which selectively form charge-transfer complexes with the electron-deficient acceptor. Embedding in amorphous polymer matrix or phys. grinding could trigger the charge-transfer luminescence with adjusted wavelengths in a general manner. X-ray diffraction results suggest the multiple binding modes between donor and acceptor. And, the solution-processed coassembly could selectively exhibit circularly polarized luminescence with high dissymmetry g-factors. This work illustrates a noncovalent charge-transfer strategy to construct luminescent and chiroptical organic composites based on the easy-accessible and economic chiral N-terminal aromatic amino acids.

Chinese Chemical 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 C7H3BrF3I, Synthetic Route of 71989-31-6.

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