Tag: M.W=150-200

Yasui, Kengo published the artcileUnsymmetrical Ketone Synthesis via a Three-Component Connection Reaction of Organozincs, Allylating Agents, and Carbon Monoxide, Name: 3-Methylbut-2-en-1-yl benzoate, the publication is Journal of Organic Chemistry (1995), 60(5), 1365-80, database is CAplus.

A wide variety of organozincs [diethylzinc, alkylzinc halides, IZn(CH₂)_nCO₂Et [n = 2, 3 (5)], and IZn(CH₂)_nCN (n = 2-6)] undergo a three-component connection reaction with carbon monoxide and allylic benzoates or phosphates to furnish unsym. ketones in good yields under 1 atm of carbon monoxide at ambient temperature by catalysis of tetrakis(triphenylphosphine)palladium in THF/HMPA. The regio- and stereoselectivities of the carbonylation show marked contrast to those reported for the palladium-catalyzed carbonylation of unsym. allylic substrates. For example, the reaction of crotyl benzoate with octylzinc iodide provides all the possible stereo- and regioisomers, i.e., cis- and trans-2-butenyl and 1-methyl-2-propenyl octyl ketones in comparable amounts The carbonylative coupling of trans- and cis-carvyl di-Et phosphates and 5 is stereospecific and proceeds with inversion of configuration at the allylic stereocenters to furnish cis- and trans-carvyl γ-(ethoxycarbonyl)propyl ketone, resp., as single diastereomers. In the absence of HMPA, the reaction feature changes dramatically and lactones and sym. keto diesters are formed in varying ratios depending on the reaction conditions. The synthetic scope of the unsym. ketones and mechanistic rationale for these unique and unprecedented reaction behaviors are discussed.

Journal of Organic Chemistry published new progress about 5205-11-8. 5205-11-8 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Benzene,Ester, name is 3-Methylbut-2-en-1-yl benzoate, and the molecular formula is C9H9BN2O3, Name: 3-Methylbut-2-en-1-yl benzoate.

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

Takagi, Koji published the artcileSafe Removal of the Allyl Protecting Groups of Allyl Esters using a Recyclable, Low-Leaching and Ligand-Free Palladium Nanoparticle Catalyst, Name: 3-Methylbut-2-en-1-yl benzoate, the publication is Advanced Synthesis & Catalysis (2015), 357(9), 2119-2124, database is CAplus.

A safe, facile, ligand-free and low-leaching (up to 0.04ppm) method for the removal of allyl, prenyl and benzyl protecting groups from the corresponding esters using a non-flammable, sulfur-modified gold-supported palladium (SAPd) nanoparticle catalyst was developed. The catalyst itself was found to be recyclable and the reaction appeared to proceed on the surface of the SAPd.

Advanced Synthesis & Catalysis published new progress about 5205-11-8. 5205-11-8 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Benzene,Ester, name is 3-Methylbut-2-en-1-yl benzoate, and the molecular formula is C26H41N5O7S, Name: 3-Methylbut-2-en-1-yl benzoate.

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

Chiloeches, A. published the artcileBiobased polymers derived from itaconic acid bearing clickable groups with potent antibacterial activity and negligible hemolytic activity, Quality Control of 617-52-7, the publication is Polymer Chemistry (2021), 12(21), 3190-3200, database is CAplus.

Herein, the authors report, for the first time, the synthesis of clickable polymers derived from biobased itaconic acid, which was used for the preparation of novel cationic polymers with antibacterial properties and low hemotoxicity via click chem. Itaconic acid (IA) was subjected to chem. modification by incorporating clickable alkyne groups on the carboxylic acids. The resulting monomer with pendant alkyne groups was easily polymerized and copolymerized with di-Me itaconate (DMI) by radical polymerization The feed molar ratio of comonomers was varied to precisely tune the content of alkyne groups in the copolymers and the amphiphilic balance. Subsequently, an azide with a thiazole group, which is a component of the vitamin thiamine (B1), was attached onto the polymers by copper-catalyzed azide-alkyne cycloaddition (CuAAC) click chem. leading to triazole linkages. N-Alkylation reactions of the thiazole and triazole groups with Me and Bu iodides provide the corresponding itaconate derivatives with pendant azolium groups. The copolymers with variable cationic charge densities and hydrophobic/hydrophilic balances, depending on the comonomer feed ratio, display potent antibacterial activity against gram-pos. bacteria, whereas the activity was almost null against gram-neg. bacteria. Hemotoxicity assays demonstrated that the copolymers exhibited negligible hemolysis and excellent selectivity, more than 1000-fold, for gram-pos. bacteria over human red blood cells.

Polymer Chemistry published new progress about 617-52-7. 617-52-7 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Aliphatic hydrocarbon chain,Ester, name is Dimethyl itaconate, and the molecular formula is C7H10O4, Quality Control of 617-52-7.

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

Alarcon, Rafael T. published the artcileA new acrylated monomer from macaw vegetable oil that polymerizes without external photoinitiators, Formula: C11H15NO2, the publication is Journal of Polymer Research (2021), 28(11), 425, database is CAplus.

The photopolymerization process has been widely studied due to its use in painting/coating, dentistry, creating photoresist materials and more recently in 3D printing. Therefore, new monomers have been synthesized to be used in this growing area. Here, a new Brazilian biomass derived, renewable monomer from macaw vegetable oil is presented. This monomer can self-polymerize without photoinitiation under UV light, reaching a monomer conversion of 75% and a conversion of 88% when Et 4-(dimethylamino)benzoate is present as a coinitiator. Furthermore, the final polymer has an orange color under visible light and exhibits fluorescence (a blue color) under UV radiation. Monomers and polymers formed from macaw (macauba) vegetable oil are thermally stable up to 220°C, as evidenced by thermogravimetry (TG). The polymers formed also exhibited a glass transition temperature of 2.6°C, as observed in differential scanning calorimetry (DSC) curves and dynamic-mech. anal. (DMA). This new monomer presents an alternative monomer to be used in 3D printing, in a similar manner to other vegetable oils such as soybean and linseed.

Journal of Polymer Research published new progress about 10287-53-3. 10287-53-3 belongs to esters-buliding-blocks, auxiliary class Amine,Benzene,Ester, name is Ethyl 4-dimethylaminobenzoate, and the molecular formula is C11H15NO2, Formula: C11H15NO2.

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

Al-eesa, N. A. published the artcileRemineralizing fluorine containing bioactive glass composites, HPLC of Formula: 10287-53-3, the publication is Dental Materials (2021), 37(4), 672-681, database is CAplus and MEDLINE.

The objective was to investigate the mech. properties, fluoride release and apatite formation of resin based dental composites based on a fluoride containing Bioactive Glass (BG) with and without a silylating agent. A SiO₂-P₂O₅-CaO-SrO-Na₂O-CaF₂ BG was synthesized by the melt quench route. This glass and a com. available inert glass (IG) were incorporated into a light cured BisGMA-TEGMA resin. The composite resins were then evaluated in terms of their ability to form apatite by Fourier Transform IR spectroscopy (FTIR) and by SEM (SEM) following immersion in artificial saliva at pH 4 (AS4) and pH 7 (AS7). The experiments were performed with and without silylation of the BG. The compressive strength and flexural strength were determined after 1, 28 and 84 days of immersion in the AS4 and AS7 immersion media. The FTIR spectra of the BG composites exhibited split bands at approx. 560 and 600 cm^-1 corresponding to a apatite formation in the surface or on the surface under all immersion conditions. SEM showed the presence of a reacted layer of glass particles in the composite surface and the presence of a surface layer of apatite in AS7. The compressive strength and flexural strength were significantly higher for the silylated BG composites. The strengths of both silylated and non silylated BG composites and IG composites decreased upon immersion. BG composites exhibit reduced strengths upon immersion but still exhibit strengths comparable to existing composites after 84 days of immersion.

Dental Materials published new progress about 10287-53-3. 10287-53-3 belongs to esters-buliding-blocks, auxiliary class Amine,Benzene,Ester, name is Ethyl 4-dimethylaminobenzoate, and the molecular formula is C11H15NO2, HPLC of Formula: 10287-53-3.

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

Gutierrez Gonzalez, Jessica published the artcileLong PEO-based nanoribbons generated in a polystyrene matrix through reaction-induced microphase separation followed by a fast crystallization process, Recommanded Product: Ethyl 4-dimethylaminobenzoate, the publication is Soft Matter (2021), 17(8), 2279-2289, database is CAplus and MEDLINE.

A dispersion of elongated nanostructures with a high aspect ratio in polymer matrixes has been reported to provide a material with valuable properties such as mech. strength, barrier effect and shape memory, among others. In this study, we show the procedure to achieve a distribution of elongated crystalline nanodomains in a PS matrix employing the self-assembly of amphiphilic block copolymers (BCP). The selected BCP was polystyrene-block-polyethylene oxide (PS-b-PEO). It was dissolved at 10 wt% in a styrene (St) monomer and the blend was slowly photopolymerized over four days at room temperature, until the reaction was arrested by vitrification. This blend was initially homogeneous and nanostructuration took place in an early stage of the polymerization as a result of the microphase separation (MS) of PEO blocks. Due to its high tendency to crystallize, demixed PEO blocks crystallized almost concomitantly with MS triggering the growing of the nanostructures. Thus, the time window between the onset of crystallization and the vitrification of the matrix was almost four days, allowing all micelles to have the opportunity to couple to a growing nanostructure. As a result, a population of nanoribbons with average lengths surpassing 10μm dispersed in a PS matrix was obtained. It was demonstrated that these ribbon-like nanostructures are preserved as long as the heating temperature is located below the T_g of the matrix. If the material is heated above this temperature, softening of the matrix allows the breakup of the molten PEO nanoribbons due to Plateau-Rayleigh instability.

Soft Matter published new progress about 10287-53-3. 10287-53-3 belongs to esters-buliding-blocks, auxiliary class Amine,Benzene,Ester, name is Ethyl 4-dimethylaminobenzoate, and the molecular formula is C11H15NO2, Recommanded Product: Ethyl 4-dimethylaminobenzoate.

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

Maniar, Dina published the artcileEnzymatic synthesis and characterization of muconic acid-based unsaturated polymer systems, Synthetic Route of 627-93-0, the publication is Polymer International (2021), 70(5), 555-563, database is CAplus.

The design of unsaturated aliphatic (co)polyester systems, based on different diester-modified muconic acid isomers, was performed via an eco-friendly pathway by utilizing enzymic polymerization using Candida antarctica lipase B (CALB) as catalyst. The obtained fully unsaturated oligoesters and polyesters reached lower mol. weights from 2210 to 2900 g mol-1 for the cis,cis-(Z,Z)-muconate isomer, and higher mol. weights of up to 21 200 g mol-1 for the polymers with cis,trans-(Z,E) isomeric structures. The obtained (co)polyesters were thoroughly characterized and compared with their saturated polyester analogs. The applied biobased catalyst Novozym435 (an immobilized form of CALB) showed higher selectivity towards the open cis,trans-muconate compared to the more closed-structure cis,cis-muconate. Anal. of 1H NMR anal. showed that alkene functionality is present, and no stereo conformational changes were detected in the resulting polymers. The thermal properties of the muconate-based polyesters showed a glass transition between -7 and 12°C, and a one-step degradation process with a maximum rate of weight loss between 415 and 431°C, depending both on the conformation of the applied diester derivatives and on the segment lengths of the polyoxyalkylenes. Mass spectrometric anal. of the resulting saturated and unsaturated polyesters revealed five different microstructures with different terminal end groups, such as ester/hydroxyl, acid/ester, ester/ester and acid/hydroxyl, and cyclic polyesters without functional end groups. Overall, this study demonstrates that enzymic polymerization is a robust approach for the synthesis of unsaturated polyesters.

Polymer International published new progress about 627-93-0. 627-93-0 belongs to esters-buliding-blocks, auxiliary class Ploymers, name is Dimethyl adipate, and the molecular formula is C8H14O4, Synthetic Route of 627-93-0.

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

Maniar, Dina published the artcileEnzymatic Synthesis of Muconic Acid-Based Polymers: Trans, Trans-Dimethyl Muconate and Trans, β-Dimethyl Hydromuconate, Computed Properties of 627-93-0, the publication is Polymers (Basel, Switzerland) (2021), 13(15), 2498, database is CAplus and MEDLINE.

The vast majority of commodity polymers are acquired from petrochem. feedstock, and these resources will plausibly be depleted within the next 100 years. Therefore, the utilization of carbon-neutral renewable resources for the production of polymers is crucial in modern green chem. Herein, we report an eco-friendly strategy that uses enzyme catalysis to design biobased unsaturated (co)polyesters from muconic acid derivatives This method is an attractive pathway for the production of well-defined unsaturated polyesters with min. side reactions. A suite of characterization techniques was performed to probe the reaction mechanism and properties of the obtained polyesters. It is rationalized that the alkene functionality of the muconate monomers plays an important role in the enzyme catalysis mechanism. The rendered polyesters possessed excellent thermal stabilities and unreacted alkene functionality that can consecutively undergo chain extension, copolymerization, or act as an anchor for other functional groups. These properties open new avenues in the fields of unsaturated polyester resins and photosensitive coatings.

Polymers (Basel, Switzerland) published new progress about 627-93-0. 627-93-0 belongs to esters-buliding-blocks, auxiliary class Ploymers, name is Dimethyl adipate, and the molecular formula is C8H14O4, Computed Properties of 627-93-0.

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

Andreev, V. M. published the artcileThe synthesis of esters of 2-methyl-2-buten-4-ol (prenol) and 2-methyl-1-buten-4-ol (isobutenyl carbinol), Recommanded Product: 3-Methylbut-2-en-1-yl benzoate, the publication is Pishchevaya Promyshlennost (Moscow, Russian Federation) (1992), 22, database is CAplus.

Perfumes RCO₂R’ (RCO₂ = benzoate, cinnamate, salicylate, isobutyrate, phenylacetate, phenoxyacetate, nicotinate; R’ = prenyl, isobutenylcarbinyl) were prepared in ≤79% yield in the K₂CO₃-catalyzed transesterification of RCO₂Me with R’OH. The odors were evaluated.

Pishchevaya Promyshlennost (Moscow, Russian Federation) published new progress about 5205-11-8. 5205-11-8 belongs to esters-buliding-blocks, auxiliary class Alkenyl,Benzene,Ester, name is 3-Methylbut-2-en-1-yl benzoate, and the molecular formula is C12H14O2, Recommanded Product: 3-Methylbut-2-en-1-yl benzoate.

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

Oliveira, Michelle Leal published the artcileLong-term bond strength of glass fiber post to composite resin does not depend on surface treatment with silane coupling agent or universal adhesive, Related Products of esters-buliding-blocks, the publication is International Journal of Adhesion and Adhesives (2021), 102931, database is CAplus.

This study evaluated the effect of glass fiber post (GFP) surface treatment with or without a silane coupling agent, associated with adhesive systems with or without silane in their composition, on the long-term bond strength to resin composite. Sixty GFPs (Whitepost DC number 2, FGM) were cleaned using 70% ethanol, and randomly divided into two groups, either with or without pretreatment with silane (Ceramic Primer, 3 M ESPE), for 60 s. Each group was further subdivided into three groups, according to the adhesive system applied over the GFP (n = 10): UAS (Scotchbond Universal, 3 M ESPE), E&R – etch-and-rinse adhesive system (Adper Single Bond Plus, 3 M ESPE), and a control group with no adhesive system. The GFPs were centralized in a cylindrical matrix, and a nanoparticulate resin composite (Filtek Supreme Ultra, 3 M ESPE) was inserted and photoactivated. After 48 h, the samples were sectioned in slices, two of which were immediately (48 h) submitted to the push-out bond strength test, and another two, after 6 mo of storage in water. The failure mode was evaluated with a stereomicroscope under 40x magnification, and classified using scores. Three-way ANOVA (α = 0.05) showed that the triple interaction of pretreatment with silane, use of adhesive and time period were significant (p = 0.019). After 48 h, the application of silane resulted in a significant increase in bond strength values, regardless of the adhesive application (p = 0.013), but this effect was no longer observed after 6 mo (p = 0.677). Application of UAS did not influence bond strength values, regardless of silane application or storage time (p > 0.05). As for E&R, significantly higher bond strength was observed after 6 mo, compared with 48 h (p = 0.040). When post silanization was performed with no adhesive system, there was no difference in bond strength between 48 h and 6 mo storage time (p > 0.05). When there was neither silanization, nor an adhesive system, a significantly higher bond strength was observed after 6 mo, compared with 48 h (p < 0.05). Most of the failure types were classified as mixed in both of the water storage time periods. The long-term bond strength of the GFP to composite resin did not depend on post surface treatment with silane, or application of either a UAS or a E&R system.

International Journal of Adhesion and Adhesives published new progress about 10287-53-3. 10287-53-3 belongs to esters-buliding-blocks, auxiliary class Amine,Benzene,Ester, name is Ethyl 4-dimethylaminobenzoate, and the molecular formula is C11H15NO2, Related Products of esters-buliding-blocks.

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