Kinetics based on the base-catalyzed mechanism of a click reaction between glycol dimercaptoacetate and glycidyl phenyl ether

Yao, Zhen; Boen, Dai; Yu, Yunfei; Ji, Haiwei; Zhou, Lizhong; Cao, Kun

doi:10.1039/c6ra26477h

Cited by 6 publications

(3 citation statements)

References 22 publications

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“…[24] On the other hand, deprotonation itself might take some time, depending on base and solvent. [25] Note the need for reversibility here, which precludes e. g. metal hydrides as deprotonating agents. Another possibility, albeit much slower than carbanion inversion, is base catalyzed enolization, which also involves initial deprotonation, giving first a mesomerismstabilized enolate, unless enolization is concerted, yielding directly the enol.…”

Section: Resultsmentioning

confidence: 99%

Speeding up Viedma Deracemization through Water‐catalyzed and Reactant Self‐catalyzed Racemization

et al. 2020

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Viedma deracemization is based on solution phase racemization, dissolution of racemic or scalemic conglomerates and crystal growth through autocatalytic cluster formation. With rate limiting racemization, its acceleration by appropriate catalysts may result in speeding up deracemization. A conglomerate‐forming chiral compound may principally racemize directly, or via reverse of its formation reaction. For a hydrazine derivative, we investigated available racemization pathways in presence of pyrrolidine or thiourea amine as base catalysts: via Mannich or aza‐Michael reaction steps and their reverse, or by enolization. Racemization by enolization was computationally found to dominate, both under water‐free conditions and in presence of water, involving a multitude of different pathways. Faster racemization in presence of water resulted indeed in more rapid deracemization, when the base was pyrrolidine. Under water‐free conditions, the role of water as enolization catalyst is assumed by chiral hydrazine itself – in autocatalytic racemization and in which both reactant and product are catalysts.

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Section: Resultsmentioning

confidence: 99%

Speeding up Viedma Deracemization through Water‐catalyzed and Reactant Self‐catalyzed Racemization

et al. 2020

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“…Thiols also have high pKa values. Thiol groups are reportedly deprotonated by the base catalyst to form thiolate anions (Yao et al., ).…”

Section: Resultsmentioning

confidence: 99%

Effects of Manufacturing Processing Conditions on Retronasal‐Aroma Odorants from a Milk Coffee Drink

Ikeda

Akiyama

Hirano

et al. 2018

Journal of Food Science

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To develop a ready‐to‐drink (RTD) milk coffee that retains the original coffee flavor, the effects of manufacturing processing conditions on retronasal‐aroma (RA) odorants were investigated by gas chromatography‐olfactometry (CharmAnalysis™) using an RA simulator (RAS). Twenty‐nine of 33 odorants detected in the RAS effluent (RAS odorants) were identified. The detected odorants were classified into 19 odor‐description groups. The total odor intensity (charm value, CMV) of all coffee RAS odorants decreased approximately 68% following pH adjustment, whereas the total CMV increased 6% to 7% following ultra‐high‐temperature sterilization. The total CMV ratio (about 83%) of the milk coffee produced using a new blending‐after‐sterilization (BAS) process without pH adjustment of the coffee was greater than that (approximately 56%) prepared using a conventional blending‐before‐sterilization (BBS) process with pH adjustment. In BAS‐processed milk coffees, the total CMV ratio (91%) with infusion (INF)‐sterilized reconstituted milk (r‐milk) was greater than that (83%) of plate (PLT)‐sterilized r‐milk. Principal component analysis of odor‐description CMVs indicated that the effect of coffee pH adjustment on odor characteristics was greater than that of sterilization, that BAS and BBS samples differed, and that BAS milk coffee prepared using INF sterilization was more similar to homemade milk coffee (blending unsterilized coffee without pH adjustment with PLT‐sterilized milk) than milk coffee prepared using PLT sterilization. In conclusion, the BAS process using INF sterilization is superior for manufacturing RTD milk coffee that retains odor characteristics similar to targeted homemade milk coffee. Practical Application Ready‐to‐drink milk coffee beverages produced using conventional blending‐before‐sterilization methods do not retain their original coffee flavor following adjustment of the pH of the coffee during manufacturing. The use of newly developed blending‐after‐sterilization methods, by contrast, produces ready‐to‐drink milk coffee with an aroma more similar to that of homemade milk coffee, as demonstrated using an analytical system for characterizing food product aromas. The blending‐after‐sterilization process is now being used in Japan to produce ready‐to‐drink milk coffee beverages.

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“…The broad range of available amines has permitted, most often, the fine‐tuning of the final properties of resulting thermosets 10,11 . Recently, there is a growing interest in the base‐catalyzed “thiol‐epoxy” reaction, which is categorized as a click reaction because it is selective, clean (no byproducts), and proceeds under mild reactive conditions 12,13 . Through this click reaction, and using appropriate modifiers, DGEBA‐based SMP with well‐defined network structure have been prepared 14 .…”

Section: Introductionmentioning

confidence: 99%

Enhanced mechanical performance of aDGEBAepoxyresin‐basedshape memory polymer by introducing graphene oxide via covalent linking

Romero-Zúñiga

Navarro-Rodríguez

Treviño-Martínez

2021

J of Applied Polymer Sci

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Shape memory polymers (SMP) are prepared, via dual thiol‐epoxy/thiol‐ene reactions, from diglycidyl ether of bisphenol A (DGEBA), a trithiol (TMP), a tetraallyl amine (TAA), and small amounts (0.1–0.5 wt.%) of graphene oxide either pristine (GO) or functionalized with methacrylate groups (GOM). The incorporation of GOM to the epoxy resin network permits a good load transfer, which is reflected in improved properties such as Young modulus (from 220 to 519 MPa), tensile strength (from 46.3 to 69.2 MPa), Izod impact strength (from 0.051 to 0.42 J/mm), torque (from 0.008 to 0.031 Nm), and glass transition temperature (from 75 to 105°C). Such improvement in properties is attributed to the incorporation of GOM via covalent linking, which is a good strategy for improving polymer‐particle interaction and particle dispersion. The epoxy‐based SMP also show high storage modulus (up to 2.36 GPa) and high deformation capacity, which are reflected in good shape fixity (between 97% and 100%) and thermo‐induced shape recovery (between 97% to 99.7%) behaviors in flexion mode tests.

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Kinetics based on the base-catalyzed mechanism of a click reaction between glycol dimercaptoacetate and glycidyl phenyl ether

Abstract: The kinetics model of the thiol–epoxy reaction was built, and the parameters of elementary reactions were obtained according to the well-defined base-catalyzed mechanism.

Cited by 6 publications

References 22 publications

Speeding up Viedma Deracemization through Water‐catalyzed and Reactant Self‐catalyzed Racemization

Speeding up Viedma Deracemization through Water‐catalyzed and Reactant Self‐catalyzed Racemization

Effects of Manufacturing Processing Conditions on Retronasal‐Aroma Odorants from a Milk Coffee Drink

Enhanced mechanical performance of aDGEBAepoxyresin‐basedshape memory polymer by introducing graphene oxide via covalent linking

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