Category: 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

Doering, W. v. E. published the artcileSynthesis of substituted tropolones, SDS of cas: 20029-52-1, the publication is Journal of the American Chemical Society (1953), 297-303, database is CAplus.

By photochem. decomposition of CH₂N₂ (I) in a substituted benzene (Ia) and oxidation of the resulting tropilidene (II) with KMnO₄, β- (III) and γ- iso-Pr-(IV), β- (V) and γ-cyclohexyl- (VI), 4,5-tetramethylene- (VII), and β- (VIII) and γ-phenyltropolone (IX) were prepared and assigned structures partly on the basis of rearrangement to the related benzoic acids. II were prepared by adding 105 g. nitrosomethylurea (X) in small portions with vigorous stirring at 0° to a mixture of 2-2.5 l. of Ia and 210 mL. 45% KOH, decanting the organic solution, drying 2 h. at 0° over KOH, irradiating with G. E. reflector sunlamps until N evolution ceased (18-42 h.), and distilling the Ia through a 17-plate column. Recovered Ia was recycled; the residues from several runs were combined and distilled through a 35-plate column to give crude II. Equimolar amounts of II and maleic anhydride refluxed 15-24 h. in 5-40 mL. dry C₆H₆ gave the following adducts (XI). The following II [R, yield (% based on X), b.p., n²⁵_D, m.p. and crude yield (%) of the XI] were prepared: iso-Pr (XII), 16.5, 172-5°, 1.4932-1.5020, 115-16°, 17; cyclohexyl (XIII), 13.3, 125.5-8° (20 mm.), 1.5245-1.5300, 201-2°, 11.3; and Ph (XIV), 8.9, 114-16° (6 mm.), 1.6164-1.6213, 131-2°, 22; also 1,2-tetramethylenetropilidene (XV), 20.0, 105-8° (27 mm.), 1.5525-1.5458, 124-5°, 11. II were oxidized by cooling 0.1 mol in 1.4 l. 95% EtOH and 60 mL. 45% KOH to -10° and adding 31.2 g. KMnO₄ in 1.4 l. H₂O over a period of 2-2.5 h. with cooling to -5°. The MnO₂ was filtered, washed with 1 l. hot H₂O, the filtrate added to the washings from which EtOH had been distilled, the solution extracted with CHCl₃, acidified with 6N H₂SO₄, extracted with CHCl₃, and the tropolone (XVI) in this extract converted to the Cu salt (XVII) with saturated aqueous Cu(OAc)₂; the CHCl₃ solutions (XVIII) of XVII obtained by repeated extraction with warm CHCl₃ were concentrated and treated as described for the individual XVI. XVIII from 13.4 g. XII concentrated to 5 mL. and cooled gave 1.22 g. XVII, m. 92-4° after crystallization from CHCl₃ (0.76 g. recovered) (from the mother liquors another 0.229 g., m. 89-91°, was obtained). A CHCl₃ solution of this treated with H₂S (cf. C.A. 46, 487f) gave 0.372 g. crude III, m. 51-2° after sublimation at 60-70° (4 mm.) and crystallization from isohexane (p-nitrobenzoate, m. 119°; α,α’-dibromo derivative, m. 132-3°); material from the second crop of XVII and mother liquors raised the yield to 2.9%. III (0.328 g.), 8 mL. dry C₆H₆, and 0.3 mL. SOCl₂ refluxed until a drop gave no color with alc. FeCl₃, concentrated, and distilled twice at 95-100° (2 mm.) gave 50% 2-chloro-4(or 6)-isopropyltropone, alk. rearrangement of which [cf. D. and K., J. Am. Chem. Soc. 74, 5683(1952)] gave 38% 3-iso-PrC₆H₄CO₂H. IV, obtained in 1.3% yield from the mother liquors from crystallization of the XVII of III, m. 80-1° [p-nitrobenzoate, m. 135°; α,α’-diBr derivative (α,α’-dibromo-γ-thujaplicin), m. 146°]; hydrogenation in 95% EtOH over PtO₂ gave 60% 5-isopropyl-1,2-cycloheptanediol, m.85-6°; treatment with SOCl₂ as for III gave 40% 2-chloro-5-isopropyltropone, which rearranged with alkali to give 17% p-iso-PrC₆H₄CO₂H. The mixed XVII of V and VI, m. 168-71° (4% yield) did not sep. on crystallization from CHCl₃; the oil obtained by H₂S treatment, sublimed at 80-90° (2 mm.) and the sublimate crystallized rapidly gave VI, m. 97-8° (p-nitrobenzoate, m. 160-1°); hydrogenation of this gave 5-cyclohexyl-1,2-cycloheptanediol, m. 123-5°; the Me ether (from VI and CH₂N₂) heated 12 h. at 120° in a sealed tube with 4 mL. absolute MeOH and 0.05 g. NaOMe gave p-cyclohexylbenzoic acid, m. 197-8°. V, m. 88-9° (p-nitrobenzoate, m. 139-40°), was recovered from the mother liquor from VI; hydrogenation gave 4-cyclohexyl-1,2-cycloheptanediol (colorless glass); the Me ether (from V and CH₂N₂) rearranged to m-cyclohexylbenzoic acid, m. 197-8°. Yields of VI and V were raised to 0.21 and 0.13% resp., based on X, by working up the mother liquors. Procedures like those above gave the following XVI [with XVI, m.p., yield (% based on X), p-nitrobenzoate m.p., XVII m.p., hydrogenation product and its m.p., Me ether m.p., Me ether rearrangement product, and its m.p. given]: VII, 130°, 0.62, 149-50.5°, 287-8°, 4,5-tetramethylene-1,2-cycloheptanediol, 74-5°, 59-65° (mixture of isomeric ethers), 5,6,7,8-tetrahydro-2-naphthoic acid, 153-4° (amide, m. 136-8°); VIII, 97°, 0.18, 144-5°, -, 4-phenyl-1,2-cycloheptanediol, 107-9°, Me ether not prepared (rearrangement of 2-chloro-4-phenyltropone, from VIII and SOCl₂, gave diphenyl-3-carboxylic acid, m. 165-6°); IX, 125-6°, 0.09, 220-1°, 342-5° (decomposition), 5-phenyl-1,2-cycloheptanediol, 97-8°, 141° (Me ether not rearranged; rearrangement of 2-chloro-5-phenyltropone, m. 158°, from IX and SOCl₂, gave diphenyl-4-carboxylic acid, m. 223-4°). UV absorption spectra of XVI are given.

Journal of the American Chemical Society 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, SDS of cas: 20029-52-1.

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

Voronenkov, V. V. published the artcileSynthesis of p-alkylbenzoic acids by one-electron oxidation of p-alkyltoluenes. MINDO/3 calculations of p-alkyltoluenes and their radical cations, Application In Synthesis of 20029-52-1, the publication is Zhurnal Organicheskoi Khimii (1989), 25(12), 2565-9, database is CAplus.

The role of σ,π-conjugation in determining the regiochem. of one-electron oxidation of the title compounds, i.e., p-MeC₆H₄CHMe₂, was investigated by MINDO/3 mol.-structure calculation The isopropyl-group C-H bond was in the plane of the aromatic ring, a conformation preventing its participation in σ,π-conjugation; two of the Me-group C-H bonds were perpendicular to the aromatic plane, however, suggesting their participation in σ,π-conjugation could significantly enhance their acidity and deprotonation affinity. Analogous results were obtained for p-cyclopropyltoluene.

Zhurnal Organicheskoi Khimii 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 C5H11NO2S, Application In Synthesis of 20029-52-1.

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

Schmidt, Philipp published the artcileFormation of a Thiol-Ene Addition Product of Asthma Medication Montelukast Caused by a Widespread Tin-Based Thermal Stabilizer, Synthetic Route of 162515-68-6, the publication is Chemical Research in Toxicology (2020), 33(12), 2963-2971, database is CAplus and MEDLINE.

We report the formation and characterization of two diastereomeric thiol-ene addition products of the asthma medication Montelukast within chewing tablets. Widespread tin-based thermal stabilizers dioctyltin bis(2-ethylhexyl thioglycolate) and monooctyltin tris(2-ethylhexyl thioglycolate), used in the manufacturing process of the medication’s forming foil, were identified as the source of the thiol reactant, showing that these stabilizers may play a part in the degradation of Montelukast and APIs with functionalities similar to those of Montelukast, which should be considered during development of medication. The isolation and anal. of these impurities was performed by HPLC and UV-vis spectroscopy. HRMS and NMR data were collected to characterize and determine the structures of these compounds

Chemical Research in Toxicology published new progress about 162515-68-6. 162515-68-6 belongs to quinuclidine, auxiliary class Thiol,Carboxylic acid,Aliphatic cyclic hydrocarbon, name is 2-(1-(Mercaptomethyl)cyclopropyl)acetic acid, and the molecular formula is C6H10O2S, Synthetic Route of 162515-68-6.

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

Koshel’, G. N. published the artcileLiquid-phase catalytic oxidation of methyl derivatives of biphenyl, Quality Control of 20029-52-1, the publication is Kinetics and Catalysis (2004), 45(6), 821-825, database is CAplus.

Liquid-phase catalytic oxidation into acids by air was studied for the following hydrocarbons: isomers of cyclohexyltoluenes and cyclohexyl derivatives of para-xylene, mesitylene, pseudocumene, cyclopentyltoluene, cyclohexyladamantane, 4-methylbiphenyl, 2,4-, 2,5- and 3,4-dimethylbiphenyls, hydroxymethylbiphenyls, and hydroxymethylbenzenes. The oxidation of cyclohexyltoluenes involves a Me group and proceeds without participation of the α-CH bond of the cyclohexyl fragment in the oxidative conversions. The reactivity of the hydrocarbons increases in the order ortho < meta < para. Consecutive conversions of the Me groups to carboxyls occur during the oxidation of dimethylbiphenyls. In 3,4- and 2,5-dimethylbiphenyls, the Me groups in the para and ortho positions, resp., are first oxidized, whereas the reactivity of both of the Me groups in 2,4-dimethylbiphenyl is virtually the same. The mechanism of the oxidation of hydroxymethylbiphenyls and hydroxymethylbenzenes involves the formation of an unstable cation radical, which is then stabilized by emitting a proton, giving hydroxybenzyl, a more stable radical.

Kinetics and Catalysis 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, Quality Control of 20029-52-1.

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

Berne, Sabina published the artcileBenzoic acid derivatives with improved antifungal activity: design, synthesis, structure-activity relationship (SAR) and CYP53 docking studies, Quality Control of 20029-52-1, the publication is Bioorganic & Medicinal Chemistry (2015), 23(15), 4264-4276, database is CAplus and MEDLINE.

Previously, the authors identified CYP53 as a fungal-specific target of natural phenolic antifungal compounds and discovered several inhibitors with antifungal properties. In this study, they performed similarity-based virtual screening and synthesis to obtain benzoic acid-derived compounds and assessed their antifungal activity against Cochliobolus lunatus, Aspergillus niger and Pleurotus ostreatus. In addition, the authors generated structural models of CYP53 enzyme and used them in docking trials with 40 selected compounds Finally, they explored CYP53-ligand interactions and identified structural elements conferring increased antifungal activity to facilitate the development of potential new antifungal agents that specifically target CYP53 enzymes of animal and plant pathogenic fungi.

Bioorganic & Medicinal Chemistry 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, Quality Control of 20029-52-1.

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

Wortmann, Martin published the artcileEffect of Isocyanate Absorption on the Mechanical Properties of Silicone Elastomers in Polyurethane Vacuum Casting, Recommanded Product: 4,4-Diaminodicyclohexyl methane, the publication is ACS Omega (2021), 6(7), 4687-4695, database is CAplus and MEDLINE.

Polyurethane vacuum casting with silicone molds is a widely used industrial process for the production of prototypes and small batches. Since the silicone casting molds absorb the isocyanate component of the curing PUR casting resin at the cavity surface, the service life of the molds is typically restricted to very few casting cycles. The successive deterioration of the material properties results from the polymerization of the absorbed isocyanate with moisture to polyurea derivatives within the silicone matrix. In this study, we show for the first time the influence of isocyanate absorption on the mech. properties of silicone elastomers as well as quant. differences between com. materials. The changes in mech. properties were quantified in terms of Shore A hardness, Young’s modulus, tensile strength, elongation at break, and complex shear modulus. It was found that the influence of the isocyanate type on the relative property changes of the silicone was significantly greater than that of the silicone used. The results show that, regardless of its hardness, the silicone absorbs considerably less methylene di-Ph diisocyanate (MDI) than hydrogenated MDI, although the latter causes less deterioration of the mech. properties and achieves a longer mold service life.

ACS Omega 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 C65H82N2O18S2, Recommanded Product: 4,4-Diaminodicyclohexyl methane.

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

King, Ryan P. published the artcileA Neophyl Palladacycle as an Air- and Thermally Stable Precursor to Oxidative Addition Complexes, COA of Formula: C28H41N2P, the publication is Organic Letters (2021), 23(20), 7927-7932, database is CAplus and MEDLINE.

The use of isolated Pd Oxidative Addition Complexes (OACs) has had a significant impact on Pd-catalyzed and Pd-mediated cross-coupling reactions. Despite their importance, widespread utility of OACs was limited by the instability of their precursor complexes. Herein, the authors report the use of Campora’s palladacycle as a new, more stable precursor to Pd OACs. Using this palladacycle, biarylphosphine ligated OACs, including those with pharmaceutical-derived aryl halides and relevance to bioconjugation, were prepared

Organic Letters 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, COA of Formula: C28H41N2P.

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

King, Ryan P. published the artcileA Ligand Exchange Process for the Diversification of Palladium Oxidative Addition Complexes, Safety of 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine, the publication is Organic Letters (2021), 23(15), 6030-6034, database is CAplus and MEDLINE.

Palladium oxidative addition complexes (OACs) have recently emerged as useful tools to enable challenging bond connections. However, each OAC can only be formed with one dative ligand at a time. As no one ligand is optimal for every cross-coupling reaction, we herein disclose a ligand exchange protocol for the preparation of a series of OACs bearing a variety of ancillary ligands from one common complex. These complexes were further applied to cross-coupling transformations.

Organic Letters 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, Safety of 2′-(Dicyclohexylphosphino)-N2,N2,N6,N6-tetramethyl-[1,1′-biphenyl]-2,6-diamine.

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

Haque, Bazle Z. published the artcileDepth of penetration experiments of S-2 glass/epoxy composites: A new experimental methodology in determining the rate dependent dynamic crush strength of composites, Recommanded Product: 4,4-Diaminodicyclohexyl methane, the publication is Composites, Part B: Engineering (2022), 109917, database is CAplus.

Depth of penetration (DoP) experiments have been conducted on thick section S-2 glass/epoxy laminates impacted by 64 grain steel projectiles over an impact velocity range of 400 m/s to 1400 m/s. Under high velocity impact, the composite under the projectile is highly compressed and crushes into powder. A theor. model is developed to reduce DoP data that relates the plastic/granular wave velocity, plastic/granular strain and strain rate during penetration to the strain rate dependent dynamic punch crush strength and plastic/granular erosion strain of composite for the first time in the literature. Punch crush strength is an important material property used in rate dependent progressive composite damage models. DoP experiments on thick section composites are presented to study the effects of fiber volume fraction, fabric architecture, and inelastic matrix behavior on depth of penetration and damage modes. The new data reduction methodol. is used to calculate the rate dependent punch crush strength of glass/epoxy laminates.

Composites, Part B: Engineering 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, Recommanded Product: 4,4-Diaminodicyclohexyl methane.

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