Tag: 100-200

Copper-Catalyzed Cascade Cyclization of Indolyl Homopropargyl Amides: Stereospecific Construction of Bridged Aza-[n.2.1] Skeletons was written by Tan, Tong-De;Zhu, Xin-Qi;Bu, Hao-Zhen;Deng, Guocheng;Chen, Yang-Bo;Liu, Rai-Shung;Ye, Long-Wu. And the article was included in Angewandte Chemie, International Edition in 2019.Quality Control of Methyl 2-thienylacetate This article mentions the following:

Catalytic cycloisomerization-initiated cascade cyclizations of terminal alkynes have received tremendous interest, and been widely used in the facile synthesis of a diverse array of valuable complex heterocycles. However, these tandem reactions have been mostly limited to noble-metal catalysis, and are initiated by an exo-cyclization pathway. Reported herein is an unprecedented copper-catalyzed endo-cyclization-initiated tandem reaction of indolyl homopropargyl amides, where copper catalyzes both the hydroamination and Friedel-Crafts alkylation process [e.g., I → II (85%)]. This method allows the practical and atom-economical synthesis of valuable bridged aza-[n.2.1] skeletons (n=3-6) with wide substrate scope, and excellent diastereoselectivity and enantioselectivity by a chirality-transfer strategy. Moreover, the mechanistic rationale for this novel cascade cyclization is also strongly supported by control experiments, and is distinctively different from the related gold catalysis. In the experiment, the researchers used many compounds, for example, Methyl 2-thienylacetate (cas: 19432-68-9Quality Control of Methyl 2-thienylacetate).

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. 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.Quality Control of Methyl 2-thienylacetate

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

Effect of roasting temperature and time on volatile compounds, total tocopherols, and fatty acids of flaxseed oil was written by Sun, Xuelian;Zhang, Bo;Han, Jiajia;Wei, Changqing;Liu, Wenyu. And the article was included in Journal of Food Science in 2022.Product Details of 695-06-7 This article mentions the following:

Roasting affects the physicochem. and nutritional qualities of flaxseed oil (FSO). The FSO samples were extracted from the roasting flaxseeds at 10-, 20-, and 30-min points and at different temperatures (140°C, 160°C, and 180°C). A total of 61 volatile compounds were identified, and the quantity of the volatile compounds increased significantly (p < 0.05) after roasting. The maximum aldehyde (25.83%) and heterocyclic content (29.26%) was obtained from the samples roasted at 200°C for 20 and 30 min, resp. The predominant fatty acid in FSO samples was linolenic acid (46.01%-49.35%), which changed dynamically during roasting. The loss of α-, γ-, and δ-tocopherol after roasting was 28.73, 109.78, and 6.67 mg/100 g, resp. The principal component anal. and hierarchical cluster anal. results showed good discrimination of the different FSO samples into three groups, which were mainly related to the roasting time. Therefore, it can be concluded that roasting time has a stronger effect on the volatile composition of FSO than the temperature during the roasting process. This work provides a basis for improving the aroma of FSO. The roasting process is used to extract flaxseed oil (FSO) from flaxseeds. Studying the physicochem. properties and quality characteristics of FSO under diverse roasting conditions is an important step in producing FSO in the food industry, which can give precise instructions to produce flaxseed oil in factories. The results of this study document the volatile constituents generated in FSO samples extracted from flaxseeds during roasting, which may help manufacturers, who are trying to develop natural and artificial FSO flavors. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Product Details of 695-06-7).

5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7) 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. 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.Product Details of 695-06-7

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

Comparison of different categories of Slovak Tokaj wines in terms of profiles of volatile organic compounds was written by Furdikova, Katarina;Machynakova, Andrea;Drtilova, Tereza;Spanik, Ivan. And the article was included in Molecules in 2020.Related Products of 118-61-6 This article mentions the following:

The present work deals with the characterization of volatile organic compounds in wines from the Slovak Tokaj wine region. Studied wine samples were divided into 3 groups-varietal wines from registered Tokaj vine varieties, film wines Tokajske samorodne dry, and naturally sweet botrytized wines Tokaj selections. The VOCs from wines were extracted using optimized solid phase microextraction and analyzed by comprehensive two-dimensional gas chromatog. coupled to high-resolution time-of-flight mass spectrometry (HRTOF-MS). In total, 176 VOCs were identified in all 46 studied samples. It was found that the total number of VOCs in varietal wines was generally higher than in botrytized wines. All three studied categories showed characteristic VOC profiles with significant differences. Varietal wines were characterized by higher concentrations of esters and terpenoids originating from grapes. The presence of γ-octalactone, (E)-6-methylhept-2-en-4-one, and lack of benzaldehyde were typical for Tokajske samorodne dry. Tokaj selections expressed the highest concentration of di-Et malate, benzaldehyde, and furfurals. Several interesting trends were also observed The concentration of fermentation products was highest in varietal wines, while long-term matured Tokaj special wines were typified by the presence of compounds related to noble-rotten raisins (2-phenylacetaldehyde, Et 2-phenylacetate, and 2-phenylethanol), wood (cis-whisky lactone), and aging (1,1,6-trimethyl-2H-naphthalene, furfural, and 5-methylfurfural). In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxybenzoate (cas: 118-61-6Related Products of 118-61-6).

Ethyl 2-hydroxybenzoate (cas: 118-61-6) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Related Products of 118-61-6

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

Enantioselective carbene insertion into the N-H bond of benzophenone imine was written by Yang, Jian;Ruan, Peiran;Yang, Wei;Feng, Xiaoming;Liu, Xiaohua. And the article was included in Chemical Science in 2019.Electric Literature of C10H11FO2 This article mentions the following:

Efficient enantioselective insertion of α-diazoesters into the N-H bond of N-sp²-hybridized benzophenone imine was realized by using Rh₂(esp)₂ and chiral guanidine cooperative catalysis. Both aliphatic and aromatic substituted α-amino esters were obtained in high yields (up to 99%) and good enantioselectivities (up to 95.5 : 4.5 er) under mild reaction conditions. In the experiment, the researchers used many compounds, for example, Ethyl 2-fluorophenylacetate (cas: 584-74-7Electric Literature of C10H11FO2).

Ethyl 2-fluorophenylacetate (cas: 584-74-7) 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. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Electric Literature of C10H11FO2

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

Domino allylic amination/Sonogashira/heterocyclisation reactions: palladium-catalysed three-component synthesis of pyrroles was written by Lamande-Langle, Sandrine;Abarbri, Mohamed;Thibonnet, Jerome;Duchene, Alain;Parrain, Jean-Luc. And the article was included in Chemical Communications (Cambridge, United Kingdom) in 2010.Name: Diethyl 2-(prop-2-yn-1-yl)malonate This article mentions the following:

Three-component reactions with 3,4-diiodoalk-2-enoic derivatives, primary amines, and terminal alkynes proceeded to give trisubstituted pyrroles, e.g., I in fair to good yields in the presence of palladium and copper catalysts under mild reaction conditions. In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Name: Diethyl 2-(prop-2-yn-1-yl)malonate).

Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9) 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. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.Name: Diethyl 2-(prop-2-yn-1-yl)malonate

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

Six Biophysical Screening Methods Miss a Large Proportion of Crystallographically Discovered Fragment Hits: A Case Study was written by Schiebel, Johannes;Radeva, Nedyalka;Krimmer, Stefan G.;Wang, Xiaojie;Stieler, Martin;Ehrmann, Frederik R.;Fu, Kan;Metz, Alexander;Huschmann, Franziska U.;Weiss, Manfred S.;Mueller, Uwe;Heine, Andreas;Klebe, Gerhard. And the article was included in ACS Chemical Biology in 2016.COA of Formula: C10H13NO2 This article mentions the following:

Fragment-based lead discovery (FBLD) has become a pillar in drug development. Typical applications of this method comprise at least two biophys. screens as prefilter and a follow-up crystallog. experiment on a subset of fragments. Clearly, structural information is pivotal in FBLD, but a key question is whether such a screening cascade strategy will retrieve the majority of fragment-bound structures. We therefore set out to screen 361 fragments for binding to endothiapepsin, a representative of the challenging group of aspartic proteases, employing six screening techniques and crystallog. in parallel. Crystallog. resulted in the very high number of 71 structures. Yet alarmingly, 44% of these hits were not detected by any biophys. screening approach. Moreover, any screening cascade, building on the results from two or more screening methods, would have failed to predict at least 73% of these hits. We thus conclude that, at least in the present case, the frequently applied biophys. prescreening filters deteriorate the number of possible X-ray hits while only the immediate use of crystallog. enables exhaustive retrieval of a maximum of fragment structures, which represent a rich source guiding hit-to-lead-to-drug evolution. In the experiment, the researchers used many compounds, for example, Ethyl 3-amino-4-methylbenzoate (cas: 41191-92-8COA of Formula: C10H13NO2).

Ethyl 3-amino-4-methylbenzoate (cas: 41191-92-8) 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. 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.COA of Formula: C10H13NO2

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

Reductive Ring Closure Methodology toward Heteroacenes Bearing a Dihydropyrrolo[3,2-b]pyrrole Core: Scope and Limitation was written by Qiu, Li;Wang, Xiao;Zhao, Na;Xu, Shiliang;An, Zengjian;Zhuang, Xuhui;Lan, Zhenggang;Wen, Lirong;Wan, Xiaobo. And the article was included in Journal of Organic Chemistry in 2014.Application of 14667-47-1 This article mentions the following:

A newly developed reductive ring closure methodol. to heteroacenes bearing a dihydropyrrolo[3,2-b]pyrrole core, e.g., I (R = n-octyl), was systematically studied for its scope and limitation. The methodol. involves (i) the cyclization of an o-aminobenzoic acid ester derivative to give an eight-membered cyclic dilactam, and (ii) the conversion of the dilactams into the corresponding diimidoyl chloride, which undergoes (iii) reductive ring closure to install the dihydropyrrolo[3,2-b]pyrrole core. The first step of the methodol. plays the key role due to its substrate limitation, which suffers from the competition of oligomerization and hydrolysis. All the dilactams could successfully convert to the corresponding diimidoyl chlorides, most of which succeeded to give the dihydropyrrolo[3,2-b]pyrrole core. The influence of the substituents and the elongation of conjugated length on the photophys. properties of the obtained heteroacenes were then investigated systematically using UV-vis spectroscopy and cyclic voltammetry. It was found that chlorination and fluorination had quite a different effect on the photophys. properties of the heteroacene, and the ring fusing pattern also had a drastic influence on the band gap of the heteroacene. The successful preparation of a series of heteroacenes bearing a dihydropyrrolo[3,2-b]pyrrole core would provide a wide variety of candidates for further fabrication of organic field-effect transistor devices. In the experiment, the researchers used many compounds, for example, Methyl 2-aminonicotinate (cas: 14667-47-1Application of 14667-47-1).

Methyl 2-aminonicotinate (cas: 14667-47-1) 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 contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Application of 14667-47-1

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

NIS-TBHP promoted oxidative coupling of C-N and C-O bonds: A metal-free approach to polysubstituted oxazoles was written by Yang, Shengxiang;Yang, Yuzhu;Li, Fei;Liu, Xiaolan. And the article was included in Tetrahedron Letters in 2020.Reference of 13669-10-8 This article mentions the following:

A metal-free approach to polysubstituted oxazoles via the oxidative coupling of readily available benzylamines and 1,3-dicarbonyl derivatives in the presence of an external base has been developed. A variety of functional groups on both of the starting materials are tolerated using this method, affording the corresponding oxazoles in moderate to good yields. Iodination was proposed as the initiation step of the reaction and a plausible mechanism has been proposed to explain the reaction pathway. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8Reference of 13669-10-8).

Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8) 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. 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 13669-10-8

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

Visible-light-mediated S-H bond insertion reactions of diazoalkanes with cysteine residues in batch and flow was written by Qin, Long-Zhou;Yuan, Xin;Cui, Yu-Sheng;Sun, Qi;Duan, Xiu;Zhuang, Kai-Qiang;Chen, Lin;Qiu, Jiang-Kai;Guo, Kai. And the article was included in Advanced Synthesis & Catalysis in 2020.HPLC of Formula: 584-74-7 This article mentions the following:

We describe the application of S-H bond insertion reactions of aryl diazoacetates with cysteine residues that enabled metal-free, S-H functionalization under visible-light conditions. MoreovThe batch and flow protocols described were applied to obtain a wide range of functionalized cysteine derivatives and cysteine-containing dipeptides, thus providing a straightforward and general platform for their functionalizations in mild conditions.er, this process could be intensified by a continuous-flow photomicroreactor on the acceleration of the reaction (6.5 min residence time). The batch and flow protocols described were applied to obtain a wide range of functionalized cysteine derivatives and cysteine-containing dipeptides, thus providing a straightforward and general platform for their functionalizations in mild conditions. In the experiment, the researchers used many compounds, for example, Ethyl 2-fluorophenylacetate (cas: 584-74-7HPLC of Formula: 584-74-7).

Ethyl 2-fluorophenylacetate (cas: 584-74-7) 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. 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.HPLC of Formula: 584-74-7

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

A Gallium-Catalyzed Cycloisomerization/Friedel-Crafts Tandem was written by Li, Hui-Jing;Guillot, Regis;Gandon, Vincent. And the article was included in Journal of Organic Chemistry in 2010.Application of 17920-23-9 This article mentions the following:

Under noble (Au, Pt, Ru) and group 13 (Ga, In) metals catalysis, 1,6-arenynes rearrange to give 1,2-dihydronaphthalenes, e.g. I, in a high yielding, regiocontrolled fashion. When the reaction is carried out in the presence of electron-rich arenes (anisole, phenol, indole derivatives), Friedel-Crafts addition may follow the cycloisomerization step to give substituted tetrahydronaphthalenes, e.g. II (R = Me, OMe, Cl, Br). Only GaX₃ (X = Br, Cl) salts proved able to catalyze these two C-C bond formation events. This specificity of gallium has been exploited for the synthesis of valuable polycyclic compounds that would be very difficult to prepare otherwise. For instance, tetrahydroisoquinolines, e.g. III, and tetrahydrobenzoazepines, e.g. IV, have been obtained by selective 6-exo-dig or 7-endo-dig cyclization of N-tethered 1,6-arenynes. DFT calculations were carried out to shed light on the mechanism and provide a rationale for this regiodivergency. Computations also reveal the fundamental role of the tether in the stabilization of carbocationic species. Differential reactivities of other types of substrates in gallium- and gold-catalyzed cascades are also exposed, showing that the two approaches are complementary. In particular, bimol. Friedel-Crafts additions are facilitated under gallium catalysis. In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Application of 17920-23-9).

Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9) 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. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Application of 17920-23-9

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