Heterocyclic Building Blocks-Quinuclidine

Larini, Paolo published the artcileOn the Mechanism of the Palladium-Catalyzed β-Arylation of Ester Enolates, Recommanded Product: 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, the publication is Chemistry – A European Journal (2012), 18(7), 1932-1944, S1932/1-S1932/163, database is CAplus and MEDLINE.

The palladium-catalyzed β-arylation of ester enolates with aryl bromides was studied both exptl. and computationally. First, the effect of the ligand on the selectivity of the α/β-arylation reactions of ortho- and meta-fluorobromobenzene was described. Selective β-arylation was observed for the reaction of o-fluorobromobenzene with a range of biarylphosphine ligands, whereas α-arylation was predominantly observed with m-fluorobromobenzene for all ligands except DavePhos, which gave an approx. 1:1 mixture of α-/β-arylated products. Next, the effect of the substitution pattern of the aryl bromide reactant was studied with DavePhos as the ligand. We showed that electronic factors played a major role in the α/β-arylation selectivity, with electron-withdrawing substituents favoring β-arylation. Kinetic and deuterium-labeling experiments suggested that the rate-limiting step of β-arylation with DavePhos as the ligand was the palladium-enolate-to-homoenolate isomerization, which occurs by a βH-elimination, olefin-rotation, and olefin-insertion sequence. A dimeric oxidative-addition complex, which was shown to be catalytically competent, was isolated and structurally characterized. A common mechanism for α- and β-arylation was described by DFT calculations With DavePhos as the ligand, the pathway leading to β-arylation was kinetically favored over the pathway leading to α-arylation, with the palladium-enolate-to-homoenolate isomerization being the rate-limiting step of the β-arylation pathway and the transition state for olefin insertion its highest point. The nature of the rate-limiting step changed with PCy₃ and PtBu₃ ligands, and with the latter, α-arylation became kinetically favored. The trend in selectivity observed exptl. with differently substituted aryl bromides agreed well with that observed from the calculations The presence of electron-withdrawing groups on these bromides mainly affected the α-arylation pathway by disfavoring CC reductive elimination. The higher activity of the ligands of the biaryldialkylphosphine ligands compared to their corresponding trialkylphosphines could be attributed to stabilizing interactions between the biaryl backbone of the ligands and the metal center, thereby preventing deactivation of the β-arylation pathway.

Chemistry – A European Journal published new progress about 1160556-64-8. 1160556-64-8 belongs to quinuclidine, auxiliary class Mono-phosphine Ligands, name is 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, and the molecular formula is C28H41N2P, Recommanded Product: 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Boisaubert, Pierre published the artcilePhoto-crosslinked Non-Isocyanate Polyurethane Acrylate (NIPUA) coatings through a transurethane polycondensation approach, Quality Control of 1761-71-3, the publication is Polymer (2020), 122855, database is CAplus.

A transurethane polycondensation pathway was used to produce acrylate terminated non-isocyanate polyurethane (NIPUA) oligomers (A-Ol) with controlled mol. weights and chem. structures. These compounds were then photocrosslinked under UV radiations to afford several NIPU acrylate coatings. The influence of the content in urethane functions as well as the chem. structures on the thermal and mech. properties of the final coatings was demonstrated. The obtained coatings exhibited thermal stabilities above 255°C, Young modulus ranging from 2.6 to 9.2 MPa, tensile strength up to 11.8 MPa and elongation at break varying from 20 to 520%.

Polymer published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Quality Control of 1761-71-3.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Boisaubert, Pierre published the artcilePolyurethane coatings from formulations with low isocyanate content using a transurethane polycondensation route, Related Products of quinuclidine, the publication is Polymer (2022), 124522, database is CAplus.

A strategy aiming to decrease the amount of isocyanate in the PU industries without changing their current facilities is proposed. Hydroxyl terminated non-isocyanate polyurethane (NIPU) oligomers (H-Ol) with controlled mol. weights and chem. structures have been prepared as precursors. They were prepared by transurethane polycondensation between bis(methylcarbamate) (BMC), hydroxyterminated poly(tetramethyleneoxide) (PTMO) and butanediol at several molar ratios. H-Ol were then reacted with a polyisocyanurate as crosslinking agent to afford several partially NIPU coatings. Polyurethanes based on the PTMO polyols and the polyisocyanurate were also prepared as controls to highlight the importance of the urethane function in the H-Ol. The influence of the chem. structures on the thermal and mech. properties of the final coatings has been investigated. The prepared coatings displayed thermal stabilities above 200°C, Young modulus ranging from 3 to 64 MPa, tensile strength values from 0.9 to 17 MPa and elongation at break varying from 25 to 530%. H-Ol with the highest urethane content gave a coating with the best adhesion properties on a metal surface. All the obtained properties were within the characteristic range of two com. PU reference coatings.

Polymer published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Related Products of quinuclidine.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Tian, Yazhou published the artcileA resveratrol-based epoxy resin with ultrahigh T_g and good processability, Quality Control of 1761-71-3, the publication is European Polymer Journal (2021), 110282, database is CAplus.

Preparing and designing an epoxy system with ultrahigh glass transition temperature (T_g > 300°C) is always a big challenge, which restrict its applications in some cutting-edge areas such as aerospace engineering and elec. electronics. Herein, a biomass-based epoxy resin (REEP) was prepared from resveratrol, and then curing behavior, thermal-mech. properties, mech. performance, thermal stability, dielec. properties and optical properties of REEP/HDDM, REEP/DGEBA/HDDM and DGEBA/HDDM were resp. studied systematically. Results suggested that the T_g of REEP/HDDM was above 320°C, higher than those of most reported epoxy systems, both derived from biomass-based and petroleum-based materials. Moreover, the tensile strength of REEP/HDDM, REEP/DGEBA/HDDM and DGEBA/HDDM were 77.8 MPa, 70.8 MPa and 63.6 MPa, resp., and the T_d5% of REEP/HDDM, REEP/DGEBA/HDDM and DGEBA/HDDM were 319.9°C, 335.1°C and 348.1°C, resp., indicating excellent mech. performance and thermal stability of the cured epoxy system. Interestingly, the REEP/HDDM exhibited outstanding blocking properties in the range of 220-400 nm (UV-light) and low flammability with compact and continuous char residues. In short, REEP, with a well-defined chem. structure, has a stiffness conjugated stilbene structure to prevent the mol. from motioning in the crosslinked network structure and three epoxy groups, thereby increasing the crosslinked d. dramatically, which endows REEP/HDDM network with outstanding comprehensive properties.

European Polymer Journal published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C6H13BO3, Quality Control of 1761-71-3.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Wang, Qin published the artcileInhibitory effects of benzoic acid derivatives on polyphenol oxidase from Pieris rapae, COA of Formula: C13H16O2, the publication is Xiamen Daxue Xuebao, Ziran Kexueban (2006), 45(3), 428-431, database is CAplus.

The title polyphenol oxidase was extracted from the 5th instar of Pieris rapae in present paper. The effects of benzoic acid derivatives on the catalysis activity of polyphenol oxidase for the oxidation of L-dopa were investigated, including terephthalaldhydic acid (a), p-methoxybenzoic acid (b), p-isopropylbenzoic acid (c), p-cyclohexylbenzoic acid (d), p-chlorobenzoic acid (e), p-fluorobenzoic acid (f), and p-bromobenzoic acid (g). The IC₅₀ of a, b, c, d and f were 10.63, 12.22, 1.75, 2.10 and 6.64 mmol/L, resp., while e and g without obvious inhibitory effects. The study results of inhibitory kinetics showed that a, c and f were competitive inhibitors, while b and d were noncompetitive ones. Their inhibition constants were determined and compared. Obviously, the inhibitory effects of c and d were higher than the other compounds, so they might have the bright prospect in the future as the insecticide.

Xiamen Daxue Xuebao, Ziran Kexueban published new progress about 20029-52-1. 20029-52-1 belongs to quinuclidine, auxiliary class Carboxylic acid,Benzene, name is 4-Cyclohexylbenzoic acid, and the molecular formula is C11H10O, COA of Formula: C13H16O2.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Wang, Wentao published the artcileMultifunctional and High Affinity Polymer Ligand that Provides Bio-Orthogonal Coating of Quantum Dots, Synthetic Route of 1353016-70-2, the publication is Bioconjugate Chemistry (2016), 27(9), 2024-2036, database is CAplus and MEDLINE.

The authors detail the design of hydrophilic metal-coordinating ligands and their use for the effective coating of luminescent quantum dots. The ligand design exploits the specific, reagent-free nucleophilic addition reaction of amine-modified mols. toward maleic anhydride to introduce several lipoic acid metal-anchors, hydrophilic zwitterion moieties and specific reactive groups along a poly(isobutylene-alt-maleic anhydride) (PIMA) chain. Tunable reactive groups tested in this study include azide, biotin, carboxyl, and amine. Cap exchange with these multi-lipoic acid ligands via a photochem. ligation strategy yields homogeneous QD dispersions that are colloidally stable over several biol.-relevant conditions and for extended periods of time. The zwitterionic coating yields compact nanoparticle size and imparts non-sticky surface properties onto the QDs, preventing protein absorption. The introduction of a controllable number of reactive groups allows conjugation of the QDs to biomols. via bio-orthogonal coupling chemistries including: (1) attachment of the neurotransmitter dopamine to QDs via amine-isothiocyanate reaction to produce a platform capable of probing interactions with cysteine in proteins, based on charge transfer interactions; (2) self-assembly of biotinylated QDs with streptavidin-dye; (3) ligation of azide-functionalized QDs to cyclooctyne-modified transferrin via copper-free click chem. for intracellular delivery. This ligand design strategy can be used to prepare an array of metal-coordinating ligands adapted for coating other inorganic nanoparticles, including magnetic and plasmonic nanomaterials.

Bioconjugate Chemistry published new progress about 1353016-70-2. 1353016-70-2 belongs to quinuclidine, auxiliary class Other Aromatic Heterocyclic,Carboxylic acid,Amide,Inhibitor,Inhibitor, name is Dbco-acid, and the molecular formula is C8H11BO2, Synthetic Route of 1353016-70-2.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Krasnikov, S. V. published the artcileSynthesis of 1,2-dibromoalkyl-substituted aromatic carboxylic acids, Application of 4-Cyclohexylbenzoic acid, the publication is Izvestiya Vysshikh Uchebnykh Zavedenii, Khimiya i Khimicheskaya Tekhnologiya (2011), 54(5), 131-132, database is CAplus.

4-(1,2-Dibromoisopropyl)benzoic acid and 4-(1,2-dibromocyclohexyl)benzoic acid (I) were synthesized using the reaction of free-radical bromination. The trans-conformation of acid I was confirmed by ¹H NMR spectroscopy and counter synthesis.

Izvestiya Vysshikh Uchebnykh Zavedenii, Khimiya i Khimicheskaya Tekhnologiya published new progress about 20029-52-1. 20029-52-1 belongs to quinuclidine, auxiliary class Carboxylic acid,Benzene, name is 4-Cyclohexylbenzoic acid, and the molecular formula is C13H16O2, Application of 4-Cyclohexylbenzoic acid.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Krasnikov, S. V. published the artcileSynthesis of 1,2-dibromoalkyl-substituted carboxylic acids of aromatic series, Recommanded Product: 4-Cyclohexylbenzoic acid, the publication is Izvestiya Vysshikh Uchebnykh Zavedenii, Khimiya i Khimicheskaya Tekhnologiya (2010), 53(9), 120-121, database is CAplus.

The 4-(1,2-dibromoisopropyl)- and 4-(1,2-dibromocyclohexyl)benzoic acids were synthesized by homolytic bromination of 4-isopropyl- and 4-cyclohexylbenzoic acids, resp. The trans-configuration of 4-(1,2-dibromocyclohexyl)benzoic acid was confirmed by both ¹H NMR spectroscopy and independent synthesis from 4-(1-cyclohexenyl)benzoic acid.

Izvestiya Vysshikh Uchebnykh Zavedenii, Khimiya i Khimicheskaya Tekhnologiya published new progress about 20029-52-1. 20029-52-1 belongs to quinuclidine, auxiliary class Carboxylic acid,Benzene, name is 4-Cyclohexylbenzoic acid, and the molecular formula is C13H16O2, Recommanded Product: 4-Cyclohexylbenzoic acid.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Black, Jacob W. published the artcileAn Optical Tweezers Platform for Single Molecule Force Spectroscopy in Organic Solvents, Application of Dbco-acid, the publication is Nano Letters (2017), 17(11), 6598-6605, database is CAplus and MEDLINE.

Observation at the single mol. level was a revolutionary tool for mol. biophysics and materials science, but single mol. studies of solution-phase chem. are less widespread. The authors develop an exptl. platform for solution-phase single mol. force spectroscopy in organic solvents. This optical-tweezer-based platform was designed for broad chem. applicability and uses optically trapped core-shell microspheres, synthetic polymer tethers, and click chem. linkages formed in situ. Stable optical trapping of the core-shell microspheres in 10 different solvents was observed, as was single mol. link formation in 4 different solvents. These experiments demonstrate how to use optical tweezers for single mol. force application in the study of solution-phase chem.

Nano Letters published new progress about 1353016-70-2. 1353016-70-2 belongs to quinuclidine, auxiliary class Other Aromatic Heterocyclic,Carboxylic acid,Amide,Inhibitor,Inhibitor, name is Dbco-acid, and the molecular formula is C19H15NO3, Application of Dbco-acid.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider

Sakakibara, Keita published the artcilePerformance improvement of epoxy polymer monolith films by reinforcing with cellulose fibers, Product Details of C13H26N2, the publication is Nettowaku Porima Ronbunshu (2020), 41(6), 245-251, database is CAplus.

In this article, we demonstrate the preparation of epoxy polymer monolith composite films with cellulose fibers for improving the mech. property, where the monolith is a porous material with a co-continuous skeletal structure. The preparation includes lamination process or simple hanging process for cellulose-fiber nonwoven sheet impregnated with monolith precursor mixtures, followed by polymerization induced phase separation based on spinodal decomposition The resulting monolith composite films were surface skin-less, exhibiting the pore sizes from 200 nm to 1.5μm. The tensile Young’s modulus and strength were higher than those of the neat monolith film and the previously-reported cellulose nanofiber-reinforced monolith films. The ionic conductivity of the composite films with lithium-ion electrolyte was comparable to that of com.-available polyolefin porous membranes. The epoxy polymer monolith composite film is expected to have a great potential as a promising separator for next-generation lithium ion batteries by taking advantage of its high heat resistance and winding channel structure.

Nettowaku Porima Ronbunshu published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C13H26N2, Product Details of C13H26N2.

Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider