Month: December 2022

Li, Xiaohu published the artcilePhosphine-catalyzed sequential (2+3)/(2+4) annulation of γ-vinyl allenoates: access to the synthesis of chromeno[4,3-b]pyrroles, Recommanded Product: Methyl 2-(3-formyl-4-hydroxyphenyl)acetate, the publication is Chemical Communications (Cambridge, United Kingdom) (2021), 57(77), 9934-9937, database is CAplus and MEDLINE.

A phosphine-catalyzed cascade (2+3)/(2+4) cyclization reaction of γ-vinyl allenoates I (R¹ = Me, Et, i-Pr, PhCH₂) with aldimine esters II (R² = 4-Me, 5-Et₂N, 6-F, 3,4-benzo, etc.; R³ = Me, Et, i-Pr) has been developed to provide a series of chromeno[4,3-b]pyrroles III that contain three contiguous stereogenic centers. The method gives good yields, excellent chemoselectivity and diastereoselectivity under mild conditions.

Chemical Communications (Cambridge, United Kingdom) published new progress about 61874-04-2. 61874-04-2 belongs to esters-buliding-blocks, auxiliary class Benzene,Phenol,Ester,Aldehyde, name is Methyl 2-(3-formyl-4-hydroxyphenyl)acetate, and the molecular formula is C10H10O4, Recommanded Product: Methyl 2-(3-formyl-4-hydroxyphenyl)acetate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Chen, Kai published the artcileEngineered Cytochrome c-Catalyzed Lactone-Carbene B-H Insertion, Computed Properties of 517-23-7, the publication is Synlett (2019), 30(4), 378-382, database is CAplus and MEDLINE.

Previous work has demonstrated that variants of a heme protein, Rhodothermus marinus cytochrome c(Rma cyt c), catalyze abiol. carbene boron-hydrogen (B-H) bond insertion with high efficiency and selectivity. Here authors investigated this carbon-boron bond-forming chem. with cyclic, lactone-based carbenes. Using directed evolution, they obtained a Rma cyt c variant BOR^LAC that shows high selectivity and efficiency for B-H insertion of 5- and 6-membered lactone carbenes (up to 24,500 total turnovers and 97.1:2.9 enantiomeric ratio). The enzyme shows low activity with a 7-membered lactone carbene. Computational studies revealed a highly twisted geometry of the 7-membered lactone carbene intermediate relative to 5- and 6-membered ones. Directed evolution of cytochrome c together with computational characterization of key iron-carbene intermediates has allowed us to expand the scope of enzymic carbene B-H insertion to produce new lactone-based organoborons.

Synlett published new progress about 517-23-7. 517-23-7 belongs to esters-buliding-blocks, auxiliary class Tetrahydrofuran,Ketone,Ester, name is 3-Acetyldihydrofuran-2(3H)-one, and the molecular formula is C6H8O3, Computed Properties of 517-23-7.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Xi, Yang published the artcileCatalytic Asymmetric Diarylation of Internal Acyclic Styrenes and Enamides, Product Details of C6H8O4, the publication is Journal of the American Chemical Society (2022), 144(18), 8389-8398, database is CAplus and MEDLINE.

Enantioselective transformations of olefins are among the most important strategies for the asym. synthesis of organic compounds Chemo-, diastereo-, and stereoselective control of reactions with internal acyclic alkenes for the construction of functionalized acyclic alkanes still remain a persistent challenge. Here, authors report a palladium-catalyzed asym. regiodivergent Heck-type diarylation of internal acyclic alkenes. The 1,2-diarylation of two accessible acyclic alkenes, cinnamyl carbamates and enamides with diazonium salts and aromatic boronic acids, furnishes products containing vicinal stereogenic centers via the stereospecific formation of carbonyl coordination-assisted transient palladacycles. Moreover, the asym. migratory diarylation of enamides enables the formation of incontiguous stereocenters by an interrupted diastereoselective 1,3-chain-walking process. This protocol streamlines access to highly functionalized multisubstituted enantioenriched carbamates and amine derivatives which are embedded in the key biol. active motifs.

Journal of the American Chemical Society published new progress about 624-49-7. 624-49-7 belongs to esters-buliding-blocks, auxiliary class Inhibitor,Natural product, name is Dimethyl fumarate, and the molecular formula is C12H14BNO2, Product Details of C6H8O4.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Chen, Zhiyan published the artcileSynthesis of indoles and carbazoles from a lignin model compound α-hydroxyacetophenone, COA of Formula: C6H10O3, the publication is Green Chemistry (2022), 24(7), 2919-2926, database is CAplus.

Herein an efficient strategy of using an oxidized lignin model compound, α-hydroxyacetophenone, as starting material to synthesize indoles or carbazoles in conjunction with using pyrroles or indoles as counterpart reagents was described. The reactions were performed using Sc(OTf)₃ as a catalyst in a bio-based green solvent, glycerol, and moderate to excellent yields were obtained. At the end of the reaction, both solvent and catalyst was recovered and reused. The novel approach presented here not only provided an eco-efficient route for the value-added conversion of lignin degradation products, but also extends the diversity of indole and carbazole derivatives, which are of potential importance in the development of functional photo-elec. materials.

Green Chemistry published new progress about 30414-53-0. 30414-53-0 belongs to esters-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Ketone,Ester, name is Methyl 3-oxovalerate, and the molecular formula is C6H10O3, COA of Formula: C6H10O3.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Lin, Chih-Yu published the artcileRhodium-Catalyzed [4+2] Annulation of N-Aryl Pyrazolones with Diazo Compounds To Access Pyrazolone-Fused Cinnolines, Recommanded Product: Methyl 3-oxovalerate, the publication is European Journal of Organic Chemistry (2021), 2021(35), 4984-4992, database is CAplus.

An efficient synthesis of novel dinitrogen-fused heterocycles such as pyrazolo[1,2-a]cinnoline derivatives have been accomplished by the rhodium(III)-catalyzed reaction of N-arylpyrazol-5-ones with α-diazo compounds This reaction proceeds through a cascade C-H activation/intramol. cyclization with a broad substrate scope. Furthermore, this protocol is successfully extended to the unusual phosphorus-containing α-diazo compounds and cyclic diazo compounds as the cross-coupling partners to deliver the two new kinds of pyrazolo[1,2-a]cinnolinones. The control experiments were performed to reveal insight into the mechanism of this reaction, involving reversible C-H activation, migratory insertion of the diazo compound, and cascade cyclization as the key steps of the transformation. Moreover, gram-scale synthesis and further transformation of the target product demonstrate the synthetic utility of the present protocol.

European Journal of Organic Chemistry published new progress about 30414-53-0. 30414-53-0 belongs to esters-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Ketone,Ester, name is Methyl 3-oxovalerate, and the molecular formula is C6H10O3, Recommanded Product: Methyl 3-oxovalerate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Lee, Zhong-Han published the artcileEffect of the Steric Hindrance and Branched Substituents on Visible Phenylamine Oxime Ester Photoinitiators: Photopolymerization Kinetics Investigation through Photo-DSC Experiments, Computed Properties of 15625-89-5, the publication is Photochemistry and Photobiology (2022), 98(4), 773-782, database is CAplus and MEDLINE.

In this work, free radical photopolymerization (FRP) kinetics for series of different phenylamine oxime ester structures (DMA-P, DEA-P, DMA-M, TP-2P, TP-2M and TP-3M) was investigated. Steric hindrance and branched substituents were prepared to realize the corresponding electronic and photopolymerization effects. The photophys., electrochem., thermal properties and radical concentration were investigated by UV-visible spectroscopy, cyclic voltammetry (CV), thermogravimetric anal. (TGA), differential scanning calorimetry (DSC) and ESR (EPR). Furthermore, the structure-reactivity relationships were also studied in detail through photo-DSC experiment We demonstrate that the introduction of alkyl chains and/or numbers of oxime esters affects significantly the photoreactivity. Under the same weight ratio of formulation and irradiated condition, TP-3M containing three oxime esters in its structure and Me group in the periphery exhibits the highest double-bond conversion efficiency. TP-3M-based formulation also shows a wide operation window under different contents and light intensities. Importantly, the photoreactivity of the TP-3M-based system was found to be better than the com. photoinitiator (OXE-01) under LED@405 nm at a low concentration This work could provide some significance to the design of oxime esters with enhanced photoreactivity.

Photochemistry and Photobiology published new progress about 15625-89-5. 15625-89-5 belongs to esters-buliding-blocks, auxiliary class Polymerization Reagents,Crosslinkers, name is Trimethylolpropane triacrylate, and the molecular formula is C15H20O6, Computed Properties of 15625-89-5.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Li, Chunfa published the artcileNMR used to study the side-reactions between peroxides and antioxidants during the reactive extrusion process of the impact polypropylene, Computed Properties of 31570-04-4, the publication is Magnetic Resonance Letters (2022), 2(2), 91-106, database is CAplus.

Side reaction pathways are observed to occur between antioxidants and peroxide during the processing of multiple resin grades mediated by controlled peroxide-induced degradation of impact polypropylene. In the present work, the reaction mechanism and main byproducts between antioxidants and peroxides were investigated. The results demonstrate that peroxides greatly accelerate the decomposition reactions, and the free radicals formed from peroxide decomposition react with, for example, the antioxidant AO1010 to produce dehydrogenation of Ph propionic unit(s) at the α position (cinnamic acid ester moiety), which generates a conjugated system leading to the increased color of the product. It is the first time to confirm the cinnamic acid moiety′s existence and report its NMR data. Further, this work confirms the dehydrogenation mechanism by comparison with different sterically hindered phenolic antioxidants. It also systematically summarizes the oxidation and degradation mechanism of AO168 and AO1010 under air and peroxide environments, resp. Based on present study, clear guidelines are obtained to improve the quality of polymeric products, especially the appearance and stability, during product development.

Magnetic Resonance Letters published new progress about 31570-04-4. 31570-04-4 belongs to esters-buliding-blocks, auxiliary class Mono-phosphine Ligands, name is Tris(2,4-di-tert-butylphenyl) phosphite, and the molecular formula is C42H63O3P, Computed Properties of 31570-04-4.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Zhang, Yu-yu published the artcileVolatile component analysis of traditional fermented flour paste by GC-MS, COA of Formula: C20H40O2, the publication is Shipin Kexue (Beijing, China) (2012), 33(16), 100-105, database is CAplus.

The volatile composition of traditional fermented flour paste was analyzed by simultaneous distillation extraction (SDE) and gas chromatog. and mass spectrometry (GC-MS). The volatile compounds separated from traditional fermented flour paste were identified by comparing their retention indexes with those of reference compounds Their relative contents were determined by peak area normalization method and their contents in traditional fermented flour paste were measured by internal standard method. A total of 113 compounds were identified accounting for 95.368% of the total peak area. Their total content in traditional fermented flour paste was 263.049 μg/g. These compounds included 10 aldehydes (11.862 μg/g), 25 esters (6.955 μg/g), 20 acids (140.596 μg/g), 14 hydrocarbons (1.934 μg/g), 9 alcs. (5.666 μg/g), 19 heterocycles (53.938 μg/g), 7 ketones (1.406 μg/g) and 9 other compounds (40.692 μg/g).

Shipin Kexue (Beijing, China) published new progress about 110-34-9. 110-34-9 belongs to esters-buliding-blocks, auxiliary class Aliphatic hydrocarbon chain,Ester, name is Isobutyl palmitate, and the molecular formula is C9H6FNO, COA of Formula: C20H40O2.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Guo, Hao published the artcileComparison of functions of pheromone receptor repertoires in Helicoverpa armigera and Helicoverpa assulta using a Drosophila expression system, Recommanded Product: (Z)-Dodec-9-en-1-yl acetate, the publication is Insect Biochemistry and Molecular Biology (2022), 103702, database is CAplus and MEDLINE.

Helicoverpa armigera and H. assulta are sympatric closely related species sharing two sex pheromone components, (Z)-11-hexadecenal (Z11-16:Ald) and (Z)-9-hexadecenal (Z9-16:Ald) but in opposite ratios, 97:3 and 3:97 resp. This feature makes them a feasible model for studying the evolution of pheromone coding mechanisms of lepidopteran insects. Despite a decade-long study to deorphanize the pheromone receptor (PR) repertoires of the two species, the comparison of the function of all PR orthologs between the two species is incomplete. Moreover, the ligands of OR14 and OR15 have so far not been found, likely due to the missing of the active ligand(s) in the compound panel and/or incompatibility of heterologous expression systems used. In the present study, we expressed the PR repertoires of both Helicoverpa species in Drosophila T1 neurons to comparatively study the function of PRs. Among those PRs, OR13, OR6, and OR14 of both species are functionally conserved and narrowly tuned, and the T1 neurons expressing each of them respond to Z11-16:Ald, (Z)-9-hexadecenol (Z9-16:OH), and (Z)-11-hexadecenyl acetate (Z11-16:Ac), resp. While HarmOR16-expressing neurons respond strongly to (Z)-9-tetradecenal (Z9-14:Ald) and (Z)-11-hexadecenol (Z11-16:OH), the neurons expressing HassOR16 mainly respond to Z9-14:Ald and also weakly respond to (Z)-9-tetradecenol (Z9-14:OH). Moreover, HarmOR14b-expressing neurons are activated by Z9-14:Ald, whereas HassOR14b-expressing neurons are sensitive to Z9-16:Ald, Z9-14:Ald, and (Z)-9-hexadecenol (Z9-16:OH). In addition, HarmOR15-expressing neurons are selectively responsive to Z9-14:Ald. However, the Drosophila T1 neurons expressing either HarmOR11 or HassOR11 are silent to all of the compounds tested. In summary, except for OR11, we have deorphanized all the PRs of these two Helicoverpa species using a Drosophila expression system and a large panel of pheromone compounds, thereby providing a valuable reference for parsing the code of peripheral coding of pheromones.

Insect Biochemistry and Molecular Biology published new progress about 16974-11-1. 16974-11-1 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is (Z)-Dodec-9-en-1-yl acetate, and the molecular formula is C14H26O2, Recommanded Product: (Z)-Dodec-9-en-1-yl acetate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Lee, Alice published the artcileGeneral Solid-Phase Method for the Preparation of Mechanism-Based Cysteine Protease Inhibitors, Recommanded Product: Ethyl 2-mercaptopropanoate, the publication is Journal of the American Chemical Society (1999), 121(43), 9907-9914, database is CAplus.

A general method has been developed for the expedient solid-phase synthesis of ketone-based cysteine protease inhibitors. The synthesis approach was designed to allow the introduction of diverse functionality at all variable sites about the ketone carbonyl using readily available precursors. The chloromethyl ketone scaffold is attached to the solid support through the newly developed hydrazine linker. Successful nucleophilic displacement of the support-bound α-chloro hydrazones with carboxylates, thiolates, and amines provides entry to the acyloxymethyl, mercaptomethyl, and amidomethyl ketone classes of cysteine protease inhibitors. Further transformations followed by cleavage from support provides the fully substituted ketone products in 40-100% overall yields after release from support. Significantly, racemization of the α-stereocenter does not occur during loading onto support, nucleophilic displacement, or cleavage from support.

Journal of the American Chemical Society published new progress about 19788-49-9. 19788-49-9 belongs to esters-buliding-blocks, auxiliary class Thiol,Aliphatic hydrocarbon chain,Ester, name is Ethyl 2-mercaptopropanoate, and the molecular formula is C5H10O2S, Recommanded Product: Ethyl 2-mercaptopropanoate.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics