Month: December 2022

Neel, Andrew J. published the artcileEnantiodivergent Fluorination of Allylic Alcohols: Data Set Design Reveals Structural Interplay between Achiral Directing Group and Chiral Anion, Name: (3-Methoxy-5-methylphenyl)boronic acid, the publication is Journal of the American Chemical Society (2016), 138(11), 3863-3875, database is CAplus and MEDLINE.

Enantioselectivity values represent relative rate measurements that are sensitive to the structural features of the substrates and catalysts interacting to produce them. Therefore, well-designed enantioselectivity data sets are information rich and can provide key insights regarding specific mol. interactions. However, if the mechanism for enantioselection varies throughout a data set, these values cannot be easily compared. This premise, which is the crux of free energy relationships, exposes a challenging issue of identifying mechanistic breaks within multivariate correlations. Herein, we describe an approach to addressing this problem in the context of a chiral phosphoric acid catalyzed fluorination of allylic alcs. using aryl boronic acids as transient directing groups. By designing a data set in which both the phosphoric and boronic acid structures were systematically varied, key enantioselectivity outliers were identified and analyzed. A mechanistic study was executed to reveal the structural origins of these outliers, which was consistent with the presence of several mechanistic regimes within the data set. While 2- and 4-substituted aryl boronic acids favored the (R)-enantiomer with most of the studied catalysts, meta-alkoxy substituted aryl boronic acids resulted in the (S)-enantiomer when used in combination with certain (R)-phosphoric acids. We propose that this selectivity reversal is the result of a lone pair-π interaction between the substrate ligated boronic acid and the phosphate. On the basis of this proposal, a catalyst system was identified, capable of producing either enantiomer in high enantioselectivity (77% (R)-2 to 92% (S)-2) using the same chiral catalyst by subtly changing the structure of the achiral boronic acid.

Journal of the American Chemical Society published new progress about 725251-81-0. 725251-81-0 belongs to ethers-buliding-blocks, auxiliary class Boronic acid and ester,Benzene,Ether,Boronic Acids,Boronic acid and ester, name is (3-Methoxy-5-methylphenyl)boronic acid, and the molecular formula is C8H11BO3, Name: (3-Methoxy-5-methylphenyl)boronic acid.

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

Karastatiris, Panayiotis published the artcileBipolar poly(p-phenylene vinylene)s bearing electron-donating triphenylamine or carbazole and electron-accepting quinoxaline moieties, Recommanded Product: 1-((2-Ethylhexyl)oxy)-4-methoxybenzene, the publication is Journal of Polymer Science, Part A: Polymer Chemistry (2008), 46(7), 2367-2378, database is CAplus.

Two new poly(phenylenevinylene)s (PPVs) carrying electron-donating triphenylamine or carbazole and electron-deficient quinoxaline units were synthesized and characterized. Their properties were compared with those of PPV containing only quinoxaline unit. The two polymers showed PL maximum at 501-510 in solution and 533-540 in thin film. Because of the presence of electron donor and acceptor units they displayed strong intramol. charge transfer (ICT) effects; hence, low-photoluminescence (PL) quantum yields. The polymers showed reversible electrochem. reduction with electron affinity of 2.75 eV and irreversible oxidation with ionization potential of 5.10-5.24 eV. Single-layer LED of configuration ITO/PEDOT/polymer/Al showed low turn-on voltage at 5 V, but limited brightness of 50-60 cdm^-2. The electroluminescence maximum was voltage-tunable varying from 500 to 542 nm.

Journal of Polymer Science, Part A: Polymer Chemistry published new progress about 146370-51-6. 146370-51-6 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether, name is 1-((2-Ethylhexyl)oxy)-4-methoxybenzene, and the molecular formula is C15H24O2, Recommanded Product: 1-((2-Ethylhexyl)oxy)-4-methoxybenzene.

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

Blank, Benoit published the artcileSelective iridium-catalyzed alkylation of (hetero)aromatic amines and diamines with alcohols under mild reaction conditions, Application of N-(4-Methoxybenzyl)pyridin-2-amine, the publication is Chemistry – A European Journal (2009), 15(15), 3790-3799, database is CAplus and MEDLINE.

A P,N-ligand-coordinated iridium complex has been employed as an efficient catalyst for the selective monoalkylation of (hetero)aromatic amines with alcs. A significant improvement of this alkylation method has been achieved, such that it can be performed at a temperature of 70°C and with catalyst loadings as low as 0.1 mol% Ir, while still affording excellent yields of secondary amines. Furthermore, the high selectivity of this catalyst for the monoalkylation of aromatic amino functions has been successfully exploited for the alkylation of diamines in both sym. and nonsym. fashions, providing a novel and very efficient synthetic tool for the preparation of N,N’-dialkylated aromatic diamines.

Chemistry – A European Journal 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, Application of N-(4-Methoxybenzyl)pyridin-2-amine.

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

Klages, Friedrich published the artcileOxonium salts. II. A new reaction for the preparation of trialkyloxonium salts, Application In Synthesis of 16332-06-2, the publication is Chemische Berichte (1953), 1322-6, database is CAplus.

cf. C.A. 47, 9897f. When 122 g. di-Me etherate (I) of HSbCl₆ in 100 cc. liquid SO₂ is treated at -30° with 32.5 g. N₂CHCO₂Et (II) while the mixture is stirred in a N stream, the SO₂ evaporated, and the residue triturated with ether, 97.5% trimethyloxonium hexachloroantimonate, [R₃O]⊕SbCl₆ symmetric difference symbol (III) (R = Me), sandlike crystals, m. 159°, is obtained. III are formed according to the reactions: R₂O.HSbCl₆ + II → [EtO₂CCH₂O⊕R₂]SbCI₆ symmetric difference symbol (IV) + N₂; IV + R₂O → EtO₂CCH₂OR + III. Evaporating the ether solution gives 50% MeOCH₂CO₂Et, b₁₃ 41-5°, b. 131° (amide, m. 92°). The di-Et homolog (48 g.) of I, treated in 100 cc. CH₂Cl₂ with 11.4 g. II at 10° and the residue triturated with ether gives 85% III (R = Et), m. 133°, and 2% EtOCH₂CO₂Et, b₁₃ 53° (amide, m. 82°). Adding dropwise 29.9 g. SbCl₅ to 20.4 g. Pr₂O in 100 cc. SO₂ at -70° and treating the precipitate with HCl give 100% Pr homolog of I, m. 72° (sealed tube, decomposition), which, treated in CH₂Cl₂ with II gives 73% III (R = Pr), m. 105° (decomposition). Adding 29.9 g. SbCl₅ dropwise to 26 g. Bu₂O in 100 cc. SO₂ while simultaneously passing HCl and N through the mixture and evaporating the SO₂ give 60 g. Bu homolog of I, m. 45-54° (sealed tube, decomposition), which with II in CH₂Cl₂ yields 33% III (R=Bu), m. 119° (decomposition). Saturating 60 g. SbCl₅ in 50 cc. CH₂Cl₂ at -70° with dry HCl in a Natm. and then adding very slowly 41 g. (Me₂CH)₂O (the mixture must not turn red) give 87% Me₂CH homolog (V) of I, m. 104°(decomposition). Adding 15.2 g. II dropwise to 72 g. V in 200 cc. CH₂Cl₂ at -5° and treating the precipitate repeatedly in CH₂Cl₂with II gives 9% [EtO₂CCH₂O(CHMe₂)₂]⊕SbCl₆ symmetric difference symbol, m. 116° (decomposition); di-iso-Am homolog, 5%, m. 89° (decomposition).

Chemische Berichte published new progress about 16332-06-2. 16332-06-2 belongs to ethers-buliding-blocks, auxiliary class Amine,Aliphatic hydrocarbon chain,Amide,Ether, name is 2-Methoxyacetamide, and the molecular formula is C3H7NO2, Application In Synthesis of 16332-06-2.

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

Metcalf, Robert L. published the artcileEvolution of olfactory receptor in oriental fruit fly Dacus dorsalis, Application In Synthesis of 2944-47-0, the publication is Proceedings of the National Academy of Sciences of the United States of America (1979), 76(4), 1561-5, database is CAplus and MEDLINE.

Male D. dorsalis from colonies in Taiwan and Hawaii were evaluated for their limit of response to various analogs of methyleugenol. The results are interpreted in terms of the geometry and allosteric requirements of the antennal receptor that triggers the characteristic methyleugenol reflex. This receptor has evolved for complementarity to all portions of the methyleugenol mol. and responds only to ortho-substituted benzenes with adjacent atoms or isoelectronic equivalents Substantial differences in responses of Taiwan and Hawaiian D. dorsalis suggest that perceptible evolution of the receptor protein has occurred during the past 50 yr. A plausible scheme for the coevolution of flies with plants containing phenylpropionoid essential oils is outlined.

Proceedings of the National Academy of Sciences of the United States of America 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, Application In Synthesis of 2944-47-0.

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

Ramadan, Nesrin K. published the artcileIon-selective electrodes for the potentiometric determination of pramoxine HCl using different ionophores, Computed Properties of 637-58-1, the publication is Acta Chimica Slovenica (2012), 59(4), 870-878, database is CAplus and MEDLINE.

Four novel pramoxine HCl (PAM) selective electrodes were investigated with 2-nitrophenyl octylether as a plasticizer in a polymeric matrix of polyvinyl chloride (PVC). Sensor 1 was fabricated using sodium-tetraphenylborate (TPB) as an anionic exchanger without incorporation of an ionophore. Sensor 2 used 2-hydroxy propyl-cyclodextrin as an ionophore, while sensors 3 and 4 were constructed using 4-sulfocalix-6-arene and 4-sulfocalix-8-arene, resp. as ionophores. Linear responses of PAM within the concentration ranges of 1.0 × 10^-4 to 1.0 × 10^-2 mol L^-1 and 1.0 × 10^-5 to 1.0 × 10^-2 mol L^-1 were obtained using sensors 1 and 2, resp. and 1.0 × 10^-6 to 1.0 × 10^-2 mol L^-1 were obtained using sensors 3 and 4. Nernstian slopes of 50.4, 54.3, 56.3, and 59.1 mV/decade over the pH range of 3.0-6.0 were observed The selectivity coefficients of the developed sensors indicated excellent selectivity for PAM. The utility of 2-hydroxy-Pr β-cyclodextrin (2HP-β-CD) and 4-sulfocalix [6,8] arene (SC 6,8) as ionophores had a significant influence on increasing the membrane sensitivity and selectivity of sensors 2, 3, and 4 compared to sensor 1. The proposed sensors displayed useful anal. characteristics for the determination of PAM in bulk powder, pharmaceutical formulation, and in biol. fluid. Validation of the method showed the suitability of the proposed electrodes for the use in the quality control assessment of the drug. Furthermore, statistical comparison between the results obtained by the proposed method and the official method of the drug was performed and no significant difference was found.

Acta Chimica Slovenica published new progress about 637-58-1. 637-58-1 belongs to ethers-buliding-blocks, auxiliary class Inhibitor, name is 4-(3-(4-Butoxyphenoxy)propyl)morpholine hydrochloride, and the molecular formula is C17H28ClNO3, Computed Properties of 637-58-1.

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

Melnik, Kristina published the artcileIdentification and Synthesis of Luteolide, a Highly Branched Macrolide Semiochemical from the Mantellid Frog Gephyromantis luteus, SDS of cas: 99438-28-5, the publication is Organic Letters (2019), 21(8), 2851-2854, database is CAplus and MEDLINE.

Luteolide is a 10-membered aliphatic macrolactone, (-)-(4R,8S,9S)-4,8-dimethylundecan-9-olide, released by the femoral gland of males of the mantellid frog Gephyromantis luteus. Its structure was established using NMR, MS, and chiral GC and confirmed by stereoselective synthesis of different stereoisomers. Among the approx. 20 current macrolides known from the Mantellidae, luteolide is the first example of a volatile macrolide furnishing three stereogenic centers and an Et side chain.

Organic Letters 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, SDS of cas: 99438-28-5.

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

Zheng, Jie published the artcileSynthesis of Antimicrobial Benzo[1,2,4]triazoloazepinium Salts and Tetrahydronaphtho[1,2-e][1,2,4]triazines by Polar [3⁺ + 2] and [4 + 2]-Cycloaddition Reactions, Quality Control of 91-16-7, the publication is Journal of Organic Chemistry (2022), 87(1), 464-478, database is CAplus and MEDLINE.

Novel annulated azaheterocycles of benzo[1,2,4]triazoloazepine and tetrahydronaphtho[1,2-e][1,2,4]triazine derivatives have been synthesized. Treatment of 2-diazenyl-1,2,3,4-tetrahydronaphthalen-2-yl acetates with BF₃·Et₂O generates 1-aza-2-azoniaallenium cation intermediates (or azocarbenium ions), which are intercepted by nitriles via cascade polar [3⁺ + 2]-cycloaddition/rearrangement reactions to afford benzo[1,2,4]triazoloazepinium salts. These literature unprecedented fused tricycle compounds have been shown to exhibit antimicrobial activity against Gram-pos. Staphylococcus aureus with in silico docking studies, suggesting that they may exhibit their antibiotic activity through inhibition of DNA gyrase. Addnl., when Et 2-(1-acetoxy-1,2,3,4-tetrahydronaphthalen-2-yl)diazene-1-carboxylate is employed, the reaction with BF₃·Et₂O produces 1,2-diaza-1,3-diene, which reacts with nitriles via a diaza-Diels-Alder reaction with inverse electron demand, leading to Et tetrahydronaphtho[1,2-e][1,2,4]triazine carboxylates. The DFT calculation has been performed to further prove the D-A reaction speculation.

Journal of Organic Chemistry published new progress about 91-16-7. 91-16-7 belongs to ethers-buliding-blocks, auxiliary class Benzene,Ether,Inhibitor,Inhibitor,Inhibitor, name is 1,2-Dimethoxybenzene, and the molecular formula is C20H40O2, Quality Control of 91-16-7.

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

da Silva, Elias Alves published the artcileColonization of oil palm empty fruit bunches by basidiomycetes from the Brazilian cerrado: deconstruction of biomass, Recommanded Product: 4-Hydroxy-3,5-dimethoxybenzaldehyde, the publication is Biofuels, Bioproducts & Biorefining (2022), 16(3), 799-815, database is CAplus.

This study aimed to establish a deconstruction process of oil palm empty fruit bunches (EFBs), employing hydrothermal and biol. pretreatments. Initially, the yields of cellulose, hemicellulose, lignin, extractives and ashes resulting from the autohydrolysis of raw EFBs were measured. The biol. pretreatment of the raw EFBs followed using eight basidiomycetes strains. Finally, an enzymic hydrolysis comparison between basidiomycetes and com. enzymes evaluated glucose and xylose yields, the synergism degree and the reduction of phenolic substances. Autohydrolysis pretreatment presented the best sugar yields after hydrolysis. However, biol. pretreatment provides enzymes and other advantages. The combination of enzymic extracts of basidiomycetes with Celluclast and Novozyme-188 Sigma gave the best glucose yield with Flavodon flavus BRM-055676 (14.78%). Synergism degree analyses showed an increase of 47% in glucose release by the cocktail of Fomes fasciatus BRM-055675 with com. enzymes. The deconstruction of EFBs by biol. pretreatment presented a 2.96 ratio loss of lignin/loss of cellulose with F. flavus BRM-055676. Finally, combinations of enzymic extracts from basidiomycetes and ascomycetes, mainly F. fasciatus BRM-055675, provided the reduction of phenolic substances. 2022 Society of Chem. Industry and John Wiley & Sons, Ltd.

Biofuels, Bioproducts & Biorefining published new progress about 134-96-3. 134-96-3 belongs to ethers-buliding-blocks, auxiliary class Immunology/Inflammation,COX,Natural product, name is 4-Hydroxy-3,5-dimethoxybenzaldehyde, and the molecular formula is C9H10O4, Recommanded Product: 4-Hydroxy-3,5-dimethoxybenzaldehyde.

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

Stolze, Sara C. published the artcileDevelopment of a Solid-Phase Approach to the Natural Product Class of Ahp-Containing Cyclodepsipeptides, Safety of (S)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)(methyl)amino)-3-phenylpropanoic acid, the publication is European Journal of Organic Chemistry (2012), 2012(8), 1616-1625, S1616/1-S1616/32, database is CAplus.

The 3-amino-6-hydroxy-2-piperidone (Ahp) containing cyclodepsipeptides are an interesting class of natural products that inhibit S1 (trypsin and chymotrypsin-like) serine protease in a reversible, noncovalent manner, turning them into potential chem. tools for protease research. Their systematic use in chem. biol. is however hampered by their tedious solution-phase chem. synthesis. To overcome this limitation, the authors report a solid-phase approach to Ahp cyclodepsipeptides that is based on the use of a masked glutamic aldehyde moiety as a general Ahp precursor mol. As a proof-of-concept, the authors therefore recently reported the solid-phase synthesis of symplocamide A. Here, the authors want to give a full account on the development and application of the masked glutamic aldehyde moiety as well as the optimization of the solid-phase synthesis, which allowed the successful synthesis of the natural product symplocamide A.

European Journal of Organic Chemistry published new progress about 77128-73-5. 77128-73-5 belongs to ethers-buliding-blocks, auxiliary class Inhibitor, name is (S)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)(methyl)amino)-3-phenylpropanoic acid, and the molecular formula is C4Br2N2O4S, Safety of (S)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)(methyl)amino)-3-phenylpropanoic acid.

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