Month: December 2022

Deng, Xiujuan published the artcileEvolution analysis of flavor-active compounds during artificial fermentation of Pu-erh tea, Formula: C11H10O, the publication is Food Chemistry (2021), 129783, database is CAplus and MEDLINE.

For the urgent need for fermentation control and product quality improvement of Pu-erh tea, gas chromatog.-mass spectrometry and odor activity value (OAV) were used to comprehensively investigate the flavor-active compounds during artificial fermentation of Pu-erh tea. A flavor wheel was constructed to expound the sensory attributes evolution during fermentation With an increased total volatiles content, 43 were significantly up-regulated and 30 were down-regulated among 131 detected volatiles. Key active compounds of three aroma types, namely fresh fragrance, fruit-fungus fragrance and stale-Qu fragrance, were analyzed based on OAV. β-damascenone was firstly found contributing most to the aroma of Pu-erh tea, followed by 1,2,3-methoxybenzene and (E,E)-2,4-nonadienal. γ-terpinene, linalool, 1,2,4-trimethoxybenzene, 1,2,3-trimethoxybenzene, and 4-ethylveratrol were identified as the potential markers responsible for aroma differences among three fermentation stages. Finally the metabolic evolution of key flavor-active compounds were systematically summarized. This study provides significant guidance in fermentation control and new product development of Pu-erh tea.

Food Chemistry published new progress about 93-04-9. 93-04-9 belongs to ethers-buliding-blocks, auxiliary class Naphthalene,Ether, name is 2-Methoxynaphthalene, and the molecular formula is C11H10O, Formula: C11H10O.

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

Lv, Wei published the artcileMolybdenum oxide decorated Ru catalyst for enhancement of lignin oil hydrodeoxygenation to hydrocarbons, Name: 1,2-Dimethoxybenzene, the publication is Renewable Energy (2022), 195-210, database is CAplus.

Herein, the catalysts of ruthenium and molybdenum oxide nanoparticles supported on activated carbon (AC) were synthesized by precursor stepwise impregnation and employed for the hydrodeoxygenation (HDO) of lignin oil. The XRD, TEM, XPS and NH₃-TPD-MS result of RuMoO_x/AC catalysts confirm that the method of loading molybdenum precursor before ruthenium precursor is advantageous for the MoO_x and Ru nanoparticles high dispersion and the reduction of MoO_x species enhance the amount of acidity of catalyst. Meanwhile, the reduction temperature of RuMoO_x/AC-1-T catalysts could effectively regulate the MoO_x species that determine the activity and product distribution of HDO. The conversion of aromatic monomers/dimers were up to 96% with high selectivity of hydrocarbon over RuMoO_x/AC-1-350 catalyst at 160 °C and 30 bar H₂. Which is attributed to the MoO₃ and Ru species possess the excellent activity of benzene ring deep hydrogenation, ether bond breaking and acid dehydration. The RuMoO_x/AC-1-350 catalyst effectively converted lignin oil (from the depolymerization of cornstalk hydrolysis residue) into hydrocarbons (56.9 wt%) and cyclohexanol/ethers (18.7 wt%) under 280 °C and 3 bar H₂. The durability of the RuMoO_x/AC-1-350 catalyst for HDO of lignin oil was also investigated and showed that the RuMoO_x/AC-1-350 catalyst had good stability, regenerability and repeatability.

Renewable Energy 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 C8H10O2, Name: 1,2-Dimethoxybenzene.

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

Gao, Han published the artcileOrigins of Lewis acid acceleration in nickel-catalyzed C-H, C-C and C-O bond cleavage, COA of Formula: C11H10O, the publication is Catalysis Science & Technology (2021), 11(13), 4417-4428, database is CAplus.

The current understanding of Lewis acid effects on transition metal catalysis is generally based on the enhanced charge transfer from metal to substrate due to the formation of Lewis acid-base adducts. The critical factors of how Lewis acids manipulate complex catalyst-substrate interactions to facilitate reactions are seldom clarified. Herein, using the energy decomposition approach, we quantify the contributions of multiple factors which account for the Lewis acid acceleration in Ni-catalyzed C-X (X = H, C, O) bond cleavage via oxidative addition The results reveal that the dominant factors for Lewis acid promotion highly depend on the features of transition states with Lewis acids. In the transition states having only heteroatom-Lewis acid interactions (e.g., C-H, C-CN and C(acyl)-O oxidative additions), the reactivity is improved majorly by enhancing charge transfer from the metal to the Lewis acid-activated substrates, which is consistent with the conventional viewpoint. However, for the transition states with heteroatom-Lewis acid and heteroatom-transition metal interactions (e.g., C(benzyl)-O and C(aryl)-O oxidative additions), the decisive factor for the improved reactivity is ascribed to the reduced Pauli repulsion between occupied orbitals. Further, in the transition states having heteroatom-Lewis acid and Lewis acid-transition metal interactions (e.g., C(benzyl)-O oxidative addition), the reaction is facilitated by strengthening electrostatics and polarization due to greater charge separation and electron delocalization effects. These three types of dominant factors are generally employed by a series of different Lewis acids in promoting Ni-catalyzed bond cleavage.

Catalysis Science & Technology published new progress about 93-04-9. 93-04-9 belongs to ethers-buliding-blocks, auxiliary class Naphthalene,Ether, name is 2-Methoxynaphthalene, and the molecular formula is C11H10O, COA of Formula: C11H10O.

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

Xu, Haiyan published the artcileDABCO as a practical catalyst for aromatic halogenation with N-halosuccinimides, Quality Control of 91-16-7, the publication is RSC Advances (2022), 12(12), 7115-7119, database is CAplus and MEDLINE.

A simple and practical synthetic approach for synthesis of aromatic halides was developed. Simple Lewis base, DABCO, was used as the catalyst. This arene halogenation process proceeded conveniently and efficiently at ambient conditions, providing the desired products in good to excellent yields and selectivity.

RSC Advances 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 C24H20Ge, Quality Control of 91-16-7.

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

Li, Laiqiang published the artcileSite-Selective Electrochemical C-H Cyanation of Indoles, Name: 2-Methoxynaphthalene, the publication is Organic Letters (2021), 23(15), 5983-5987, database is CAplus and MEDLINE.

An electrochem. approach for the site-selective C-H cyanation of indoles to form indole-carbonitriles I [R¹ = CN, Ph; R² = Me, CN, C(O)OMe, etc.; R³ = H, 4-Me, 5-F, 6-Cl, etc.; R⁴ = Me, Bn, i-Pr, etc.] employing readily available TMSCN as cyano source has been developed. The electrosynthesis relied on the tris(4-bromophenyl)amine as a redox catalyst, which achieved better yield and regioselectivity. A variety of C2- and C3-cyanated indoles were obtained in satisfactory yields. The reactions were conducted in a simple undivided cell at room temperature and obviated the need for transition-metal reagent and chem. oxidant.

Organic Letters published new progress about 93-04-9. 93-04-9 belongs to ethers-buliding-blocks, auxiliary class Naphthalene,Ether, name is 2-Methoxynaphthalene, and the molecular formula is C11H10O, Name: 2-Methoxynaphthalene.

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

Tang, Kang published the artcileEnhanced catalytic performance of trimethylsilylated Ti-MWW zeolites for the liquid-phase epoxidation of propylene with H₂O₂, Application In Synthesis of 1589-47-5, the publication is Microporous and Mesoporous Materials (2021), 111492, database is CAplus.

The titanosilicate zeolite catalyzed epoxidation of propylene with hydrogen peroxide (H₂O₂, HP) to propylene oxide (PO), the so-called HPPO, is more eco-efficient, compared to the chlorohydrin process and the epoxidation using organic hydroperoxides. However, the zeolite catalysts used in the HPPO process are easily deactivated, because the main byproduct propylene glycol (PG) and other heavy byproducts with high b.ps., derived from the solvolysis of PO, are deposited inside the zeolite micropores. In the present work, trimethylsilylated Ti-MWW zeolites, named Si-Ti-MWW, were developed for the HPPO process. In combination with the results from extensive characterizations for the prepared zeolites, it is found that the trimethylsilylation merely occurs on the external surface of Ti-MWW crystals and can significantly enhance the hydrophobicity, but not alter the coordination states of the Ti species and textural properties of the zeolites. The catalytic properties of Ti-MWW and Si-Ti-MWW were compared in propylene epoxidation The results show that the solvolysis of PO to the byproducts can be effectively inhibited over the hydrophobic zeolite surface, making Si-Ti-MWW exhibit a much higher selectivity for PO and a much better stability and reusability than the parent Ti-MWW in the HPPO process. The current study, therefore, provides a new approach to develop efficient catalysts for the HPPO process.

Microporous and Mesoporous Materials 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 C6H13BO3, Application In Synthesis of 1589-47-5.

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

Huo, Lijun published the artcileSynthesis, characterization and photovoltaic properties of poly{[1′,4′-bis-(thienyl-vinyl)]-2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene-vinylene}, Related Products of ethers-buliding-blocks, the publication is Synthetic Metals (2006), 156(2-4), 276-281, database is CAplus.

A new conjugated polymer, poly{[1′,4′-bis-(thienyl-vinyl)]-2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylene-vinylene} (PTVMEH-PPV) was synthesized via Grignard polymerization The polymer is soluble in common organic solvents such as chloroform and THF, and possesses adequate thermal stability (T_d > 246 °C). The absorption spectrum of PTVMEH-PPV film shows a broader absorption peak covering the wavelength range from 380 nm to 620 nm, which is red-shifted and broadened in comparison with that of MEH-PPV. The onset oxidation potential of the polymer is 0.12 V vs. Ag/Ag⁺, ca. 0.2 V lower than that of MEH-PPV. The band gap of the polymer measured by cyclic voltammetry is 1.82 eV, which basically agrees with that obtained from the onset wavelength of the absorption spectra. Polymer solar cell was fabricated based on the blend of PTVMEH-PPV and PCBM with a weight ratio of 1:1. The device shows the maximum external quantum efficiency of 14% at ca. 520 Nm, an open circuit voltage of 0.67 V and a power conversion efficiency of 0.32% under the illumination of AM1.5, 80 mW/cm².

Synthetic Metals 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, Related Products of ethers-buliding-blocks.

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

Hong Nguyen, Thi Anh published the artcileMetal-free, Direct Acetoxylation of Arenes, HPLC of Formula: 93-04-9, the publication is Organic Letters (2021), 23(21), 8127-8131, database is CAplus and MEDLINE.

A metal-free, direct acetoxylation reaction using sodium nitrate under an anhydrous environment of trifluoroacetic acid, acetic acid and acetic anhydride was reported. Arenes (31 examples), with oxidation potentials (E_ox, in V vs SCE) lower than benzene (2.48 V), were acetoxylated with good yields and regioselectivity. A stepwise, single electron-transfer mechanism was proposed.

Organic Letters published new progress about 93-04-9. 93-04-9 belongs to ethers-buliding-blocks, auxiliary class Naphthalene,Ether, name is 2-Methoxynaphthalene, and the molecular formula is C11H10O, HPLC of Formula: 93-04-9.

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

Pfeiffer, Steffen published the artcileInvestigation of poly(arylenevinylene)s. Part 41. Synthesis of soluble dialkoxy-substituted poly(phenylene alkenylidene)s by applying the Horner-reaction for condensation polymerization, Synthetic Route of 146370-51-6, the publication is Macromolecular Chemistry and Physics (1999), 200(8), 1870-1878, database is CAplus.

Soluble poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-1,2-ethenylene] (MEH-PPV) and its alternating copolymer poly[2,5-dimethoxy-1,4-phenylene-1,2-ethenylene-2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-1,2-ethenylene] (M3EH-PPV) were successfully synthesized by condensation polymerization of substituted terephthalaldehydes with substituted xylylene bisphosphonates via the Horner reaction. This polycondensation method was also applied to the synthesis of the analogous poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene-1,3-butadiene-1,4-diyl] (MEH-PPB), which contains a 1,3-butadiene instead of a vinylene unit. The optical data of MEH-PPV and M3EH-PPV (solid film, absolute λ_max 484, em. λ_max 589 nm) are consistent with those previously reported for MEH-PPV from the dehydrohalogenation route. In comparison to MEH-PPV, the longer alkenylene sequence of MEH-PPB exhibits a slight red shift in its absorption and fluorescence spectra (absolute λ_max 502, em. λ_max 604 nm). All 3 poly(phenylene alkenylidene)s (MEH-PPV, M3EH-PPV, and MEH-PPB) are completely soluble in common solvents. They are well-defined conjugated polymers of high mol. weight (M̅_w > 20,000) and possess all-trans structure. Optical quality solid films are easily prepared from these polymers by solution processing. Blends with phenyl-substituted PPV derivatives can also be prepared in this way. This combination of properties is highly desirable for many light-emitting, nonlinear optical, and photoelec. applications.

Macromolecular Chemistry and Physics 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, Synthetic Route of 146370-51-6.

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

Li, Qin published the artcileCharacterization of key aroma compounds and core functional microorganisms in different aroma types of Liupao tea, Application In Synthesis of 91-16-7, the publication is Food Research International (2022), 110925, database is CAplus and MEDLINE.

Liupao tea is a representative Chinese dark tea. Stale-aroma type, betelnut-aroma type and fungal-aroma type were the main aroma types of Liupao tea. In this study, aroma profiles and fungal communities of the three aroma types of Liupao tea were examined by HS-SPME/GC-MS and Illumina MiSeq anal. A total of 102 volatiles were identified and quantified in Liupao tea. Indicated by OPLS-DA anal., six aroma compounds with stale, woody, roasted notes in stale-aroma type samples, five aroma compounds possessing smoky, minty, pungent notes in betelnut-aroma type samples, and nine aroma compounds owned minty, floral, fruity, woody, green notes in fungal-aroma type samples were responsible for the different aroma characteristics formation of Liupao tea. In addition, a total of 60 fungal genera were identified in Liupao tea. Aspergillus, Wallemia, Xeromyces were the predominant fungal genera in Liupao tea. Ten fungal genera, including Wallemia, Tritirachium, Debaryomyces, Trichomonascus, unclassified_o_Hypocreales in betelnut-aroma type, Rasamsonia, Candida, Blastobotrys, Acremonium in stale-aroma type, and Xeromyces in fungal-aroma type, were identified as the biomarkers in the three aroma types of Liupao tea. Furthermore, fungal genera including Aspergillus, Wallemia, Xeromyces, and Blastobotrys were identified as the core functional microorganisms contributing to the variation of volatile profiles based on O2PLS anal. This study provided useful information on the key aroma compounds and core functional microorganisms that drive the different aroma characteristics formation of Liupao tea.

Food Research International 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 C8H10O2, Application In Synthesis of 91-16-7.

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