Month: February 2023

Stereoselective Synthesis of Vinylboronates by Rh-Catalyzed Borylation of Stereoisomeric Mixtures was written by Li, Shenhuan;Li, Jie;Xia, Tianlai;Zhao, Wanxiang. And the article was included in Chinese Journal of Chemistry in 2019.Reference of 19432-68-9 This article mentions the following:

The stereoselective preparation of vinylboronates via rhodium-catalyzed borylation of E/Z mixtures of vinyl acetates is described, and this method was also extended to synthesis of vinyldiboronates. These transformations feature high functional group compatibility and mild reaction conditions. Control experiments support a mechanism that involved a Rh-catalyzed borylation-isomerization sequence. The isomerization of (Z)-vinylboronates to (E)-isomers was also demonstrated. In the experiment, the researchers used many compounds, for example, Methyl 2-thienylacetate (cas: 19432-68-9Reference of 19432-68-9).

Methyl 2-thienylacetate (cas: 19432-68-9) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries. Acyl chlorides and acid anhydrides alcoholysis is another way to produce esters. Acyl chlorides and acid anhydrides react with alcohols to produce esters. Anydrous conditions are recommended since both acyl chlorides and acid anhydrides react with water.Reference of 19432-68-9

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Investigations on the influence of multiple extrusion on the degradation of polyolefins was written by Schweighuber, Andrea;Felgel-Farnholz, Alexander;Boegl, Thomas;Fischer, Joerg;Buchberger, Wolfgang. And the article was included in Polymer Degradation and Stability in 2021.Electric Literature of C73H108O12 This article mentions the following:

The importance of mech. recycling of polymers has increased within the last decades, especially due to numerous regulations of governments all over the world. Hereby recycling quotas are enforced to pave the way towards a closed loop recycling. During its lifetime, polymers are exposed to multiple environmental factors, which can already induce degradation However, a major factor that needs to be taken into account is the increased thermo-mech. stress during the recycling process, which may have significant impact on the quality of recyclates as well. In the present work, polyolefins (high-d. polyethylene and polypropylene) were artificially exposed to stress by continuous extrusion at varying speeds and absence or presence of stabilizers to analyze the extent to which the recycling contributes to degradation processes. These samples were analyzed for low-mol.-weight stress markers by thermodesorption gas chromatog. and by high-performance liquid chromatog. (both coupled to mass spectrometric detection). Depending on the extent of stress, the occurrence of odd-numbered linear alkane chains was revealed in polyethylene samples, and of oxidized branched alkanes in polypropylene samples. Correlations with mol. weight (determined by high temperature gel permeation chromatog.) and with decreasing concentrations of stabilizers could be demonstrated. In the experiment, the researchers used many compounds, for example, 2,2-Bis(((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)oxy)methyl)propane-1,3-diyl bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate) (cas: 6683-19-8Electric Literature of C73H108O12).

2,2-Bis(((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)oxy)methyl)propane-1,3-diyl bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate) (cas: 6683-19-8) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Electric Literature of C73H108O12

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Oxidative dearomative cross-dehydrogenative coupling of indoles with diverse C-H nucleophiles: efficient approach to 2,2-disubstituted indolin-3-ones was written by Yan, Xue;Tang, Ying-De;Jiang, Cheng-Shi;Liu, Xigong;Zhang, Hua. And the article was included in Molecules in 2020.Product Details of 1190-39-2 This article mentions the following:

The oxidative, dearomative cross-dehydrogenative coupling of indoles with various C-H nucleophiles was developed. This process features a broad substrate scope with respect to both indoles and nucleophiles, affording structurally diverse 2,2-disubstituted indolin-3-ones in high yields (up to 99%). The oxidative dimerization and trimerization of indoles were demonstrated under the same conditions. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Product Details of 1190-39-2).

malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Acyl chlorides and acid anhydrides alcoholysis is another way to produce esters. Acyl chlorides and acid anhydrides react with alcohols to produce esters. Anydrous conditions are recommended since both acyl chlorides and acid anhydrides react with water.Product Details of 1190-39-2

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Constituents of tropical medicinal plants. Part 31. Flavonoid and other constituents of Bauhinia manca was written by Achenbach, Hans;Stoecker, Markus;Constenla, Manuel A.. And the article was included in Phytochemistry in 1988.Name: Methyl 4-Hydroxy-2-methoxybenzoate This article mentions the following:

Phytochem. anal. of the stem of B. manca yielded 63 compounds, among them 6 new natural products. The new products were identified as 4 flavonoids (isoliquiritigenin 4-Me ether, liquiritigenin 4′-Me ether, 7,3′-dimethoxy-4′-hydroxyflavan, 3′,4′-dihydroxy-7-methoxyflavan) and 2,4′-dihydroxy-4-methoxydihydrochalcone and the lignan (7S,8R,8′R)-5,5′-dimethoxylariciresinol. Major constituents were 3-O-galloylepicatechin, gallic acid, cinnamic acid, β-sitosterol, and its β-D-glucoside. The 2 new flavans possess significant antifungal activity. In the experiment, the researchers used many compounds, for example, Methyl 4-Hydroxy-2-methoxybenzoate (cas: 28478-46-8Name: Methyl 4-Hydroxy-2-methoxybenzoate).

Methyl 4-Hydroxy-2-methoxybenzoate (cas: 28478-46-8) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Name: Methyl 4-Hydroxy-2-methoxybenzoate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Facile preparation of tungsten oxide doped TiO₂ photocatalysts using liquid phase plasma process for enhanced degradation of diethyl phthalate was written by Ki, Seo Jin;Park, Young-Kwon;Kim, Jung-Sik;Lee, Won-June;Lee, Heon;Jung, Sang-Chul. And the article was included in Chemical Engineering Journal (Amsterdam, Netherlands) in 2019.Name: Ethyl 2-hydroxybenzoate This article mentions the following:

In a present study, tungsten oxide was employed to improve the removal efficiency of the parent compound di-Et phthalate as well as to reduce the band gap energy of the original photocatalyst titanium dioxide. The modified photocatalyst was prepared by depositing tungsten oxide onto titanium dioxide through the liquid phase plasma. The decomposition of the parent compound was examined by varying the loading of tungsten oxide in the photocatalyst surface under different light sources, UV and blue light sources. Results showed that the band gap energy in the modified photocatalyst was lower than that of the original photocatalyst, which was attributed to increased loading of tungsten oxide in the modified photocatalyst surface resulted from an increase in the initial precursor concentrations Tungsten doped in the photocatalyst surface existed in the form of the WO₃, which led to a decrease in the sp. surface area for the modified photocatalyst. The degradation performance of the parent compound increased in response to an increase in the amount of tungsten oxide under blue light, but decreased with increasing the loading of tungsten oxide under UV light. Two intermediates observed during the photocatalytic degradation appeared to be involved in the proposed degradation pathway. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxybenzoate (cas: 118-61-6Name: Ethyl 2-hydroxybenzoate).

Ethyl 2-hydroxybenzoate (cas: 118-61-6) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Name: Ethyl 2-hydroxybenzoate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Jack Chambers’ mixed media paintings from the 1960s and 1970s: Painting technique and condition was written by Helwig, Kate;Thibeault, Marie-Eve;Poulin, Jennifer. And the article was included in Studies in Conservation in 2013.Application of 106-79-6 This article mentions the following:

This study describes the examination and anal. of four mixed media paintings from the 1960s and 1970s by Canadian artist Jack Chambers (1931-1978). The documentary evidence about his materials and methods is summarized and compared with the results of anal. of multilayer paint samples. The combination of Fourier transform IR spectroscopy (FTIR) and gas chromatog.-mass spectrometry (GC-MS) allowed the components of the paint media to be characterized: ortho-phthalate alkyd resins, iso-phthalate alkyd resins, drying oils, dammar, Pinaceae resin, and turpentine were identified in varying proportions. Many pigments and fillers were identified by FTIR and Raman and are enumerated. The effect that Chambers’ complex technique has had on the aging and degradation of the paintings is discussed. The severe cracking of the paint layers in one of the four paintings may be the result of a high proportion of dammar and turpentine diluent mixed with the alkyd paint and may also be related to the type of alkyd resin medium. Different history and environmental conditions may also be factors. In the experiment, the researchers used many compounds, for example, Dimethyl decanedioate (cas: 106-79-6Application of 106-79-6).

Dimethyl decanedioate (cas: 106-79-6) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.Application of 106-79-6

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Organic-inorganic hybrid catalysts based on ordered porous structures for Michael reaction was written by Kubota, Yoshihiro;Ikeya, Hisanori;Sugi, Yoshihiro;Yamada, Takashi;Tatsumi, Takashi. And the article was included in Journal of Molecular Catalysis A: Chemical in 2006.Product Details of 1190-39-2 This article mentions the following:

Two types of organic-inorganic hybrid base catalysts are prepared for the Michael reaction. Organic-functionalized mol. sieves (OFMSs), particularly “amine-immobilized porous silicates”, are designed based on a common idea of immobilizing active catalytic sites on silicate surface. Silicate-organic composite materials (SOCMs), such as “ordered porous silicate-quaternary ammonium composite materials”, are the precursors of ordered porous silicates obtained during the synthesis. The OFMSs are effective when the supports have large pore volume and/or surface area and the reaction is carried out in polar solvents ethanol and DMF. However, the activity of the OFMSs is considerably low in a non-polar solvent such as benzene. In contrast, the SOCMs are remarkably active in benzene. The organic cation-MCM-41 composite is more active than the composite of an organic cation and a microporous silicate such as zeolite beta and ZSM-12. In the SOCM catalysts, (SiO)₃SiO^–(⁺NR₄) moieties located at the accessible sites are considered to play some important roles. The active species are absent in the liquid phase after the reaction. The recycle of the catalyst was possible without significant loss of activity when the substrates are enough reactive. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Product Details of 1190-39-2).

malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.Product Details of 1190-39-2

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Analysis of volatile compounds in Awamori using solid phase extraction was written by Tamamura, Takako;Wada, Koji;Takara, Kensaku;Ishikawa, Nobuo;Iwabuchi, Katsuhisa;Nakasone, Yoko;Chinen, Isao. And the article was included in Nippon Shokuhin Kagaku Kogaku Kaishi in 2001.Application In Synthesis of Ethyl 2-hydroxy-3-phenylpropanoate This article mentions the following:

Awamori is distilled liquor containing up to 43% ethanol concentration A rapid and simplified technique for the anal. of major volatile compounds in Awamori using solid phase extraction was developed. A column packed with Porapak Q resin was used for extraction of volatile compounds For recovery tests, a model solution (10%-43% ethanol concentration) containing 4 kinds of alcs., 3 kinds of esters and 3 kinds of fatty acids as representative volatile compounds in Awamori was used. The recoveries of alcs. and fatty acids increased as ethanol concentration decreased. In the case of different amount of the model solution used, the recoveries of compounds showed also significant differences. The highest recovery efficiency was obtained by adjustment of ethanol concentration and amount of the sample solution Relative standard deviations were less than 7.23%. Awamori samples were firstly adjusted to 10% (volume/volume) ethanol concentration with pure water and secondly filled up to 860 mL with 10% ethanol solution Volatile compounds from Awamori were trapped on Porapak Q resin and recovered. Anal. of extracts from three varieties of Awamori by GC and GC-MS revealed significant differences in the concentration of alcs., esters, and fatty acids. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0Application In Synthesis of Ethyl 2-hydroxy-3-phenylpropanoate).

Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Application In Synthesis of Ethyl 2-hydroxy-3-phenylpropanoate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Non-Saccharomyces yeasts as bioprotection in the composition of red wine and in the reduction of sulfur dioxide was written by Windholtz, Sara;Redon, Pascaline;Lacampagne, Soizic;Farris, Laura;Lytra, Georgia;Cameleyre, Margaux;Barbe, Jean-Christophe;Coulon, Joana;Thibon, Joana;Masneuf-Pomarede, Isabelle. And the article was included in LWT–Food Science and Technology in 2021.Formula: C10H18O2 This article mentions the following:

Non-Saccharomyces yeasts have been used for many years due to their technol. potential, particularly as a “booster” of wine fruity aroma in mixed fermentations with Saccharomyces cerevisiae. Recently, a new application has emerged, bioprotection, which consists in colonizing the environment in the context of sulfite reduction in wines. The chem. and sensory impact of non-Saccharomyces yeast according to different modes of application in a context of fermentation without addition of SO2 was evaluated through trial with Merlot N. (Vitis vinifera L.). An effective niche occupation by non-Saccharomyces yeasts was highlighted during the prefermentary stages by Quant.-PCR and MALDI-TOF MS identification. Chem. anal. (GC-MS and GC MS/MS) of finish wine showed the significant impact of the dose applications, with bioprotection characterized by linear esters and sequential application by acetates of higher alc. contents. Moreover, a separation according to the species used in bioprotection was revealed. Finally, using a panel trained, the sensory anal. confirmed that the use of non-Saccharomyces yeast was a fruity booster in sequential inoculation and, to a less extent, when used as bioprotection. This study shows for the first time that the use of non-Saccharomyces yeast as a bioprotection has a significant impact on the aromatic profile of wines. In the experiment, the researchers used many compounds, for example, 5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9Formula: C10H18O2).

5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.Formula: C10H18O2

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Mutagenicity, health risk, and disease burden of exposure to organic micropollutants in water from a drinking water treatment plant in the Yangtze River Delta, China was written by Xue, Panqi;Zhao, Yameng;Zhao, Danyang;Chi, Meina;Yin, Yuanyuan;Xuan, Yanan;Wang, Xia. And the article was included in Ecotoxicology and Environmental Safety in 2021.Reference of 84-61-7 This article mentions the following:

A wide variety of organic micropollutants in drinking water pose a serious threat to human health. This study was aimed to reveal the characteristics of organic micropollution profiles in water from a drinking water treatment plant (DWTP) in the Yangtze River Delta, China and investigate the mutagenicity, health risk and disease burden through mixed exposure to micropollutants in water. The presence of organic micropollutants in seven categories in organic extracts (OEs) of water from the DWTP was determined, and Ames test was conducted to test the mutagenic effect of OEs. Meanwhile, health risk of exposure to organic micropollutants in finished water through three exposure routes (ingestion, dermal absorption and inhalation) was assessed with the method proposed by U. S. EPA, and disability-adjusted life years (DALYs) were combined to estimate the disease burden of cancer based on the carcinogenic risk (CR) assessment. The results showed that 28 organic micropollutants were detected in the raw and finished water at total concentrations of 967.28 ng/L and 1073.45 ng/L, resp., of which phthalate esters (PAEs) were the dominant category (95.79% in the raw water and 96.61% in the finished water). Although the results of the Ames test for OEs were neg. and the non-carcinogenic hazard index of the organic micropollutants in the finished water was less than 1 in all age groups, the total CR was 2.17 x 10-5, higher than the negligible risk level (1.00 x 10-6). The total DALYs caused by the organic micropollutants in the finished water was 2945.59 person-years, and the average individual DALYs was 2.21 x 10-6 per person-year (ppy), which was 2.21 times the reference risk level (1.00 x 10-6 ppy) defined by the WHO. Exposure to nitrosamines (NAms) was the major contributor to the total CR (92.06%) and average individual DALYs (94.58%). This study demonstrated that despite the neg. result of the mutagenicity test with TA98 and TA100 strains, the health risk of exposure to organic micropollutants in drinking water should not be neglected. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Reference of 84-61-7).

Dicyclohexyl phthalate (cas: 84-61-7) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Reference of 84-61-7

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics