A comparative study on the hydrolysis of acetic anhydride and N,N-dimethylformamide: Kinetic isotope effect, transition-state structure, polarity, and solvent effect

Cooper, William C.; Chilukoorie, Abhinay; Polam, Suhesh; Scott, Dane W.; Wiseman, Floyd L.

doi:10.1002/poc.3701

Cited by 8 publications

(4 citation statements)

References 36 publications

(39 reference statements)

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“…However, it should not be forgotten that DMF is far from being an inert solvent [90]. Its hydrolysis reaction has been studied in detail [91,92] and DMF has even been used as a drying agent [93]! Clearly, this would not be an acceptable procedure for an industrial production and a different strategy must be pursued to reach complete conversion.…”

Section: Scheme 3 Byproducts Observed By Gc-msmentioning

confidence: 99%

Palladium/iodide catalyzed oxidative carbonylation of aniline to diphenylurea: Effect of ppm amounts of iron salts

Ferretti

Barraco

Gatti

et al. 2019

Journal of Catalysis

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Section: Scheme 3 Byproducts Observed By Gc-msmentioning

confidence: 99%

Palladium/iodide catalyzed oxidative carbonylation of aniline to diphenylurea: Effect of ppm amounts of iron salts

Ferretti

Barraco

Gatti

et al. 2019

Journal of Catalysis

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“…This causes an increase in the viscosity due to hydrogen bonding between the protonated carboxylic acid functions, limiting access of MA to the hydroxyl groups thus leading to lower DM. At TEA/MA ≥ 2 eq, TEA catalyzes the hydrolysis of the anhydride compared to nucleophilic acyl substitution reaction, favoring the formation of methacrylic acid rather than grafting on the alginate backbone and resulting in lower DM . In addition, a large excess of MA is used to achieve a higher DM.…”

Section: Resultsmentioning

confidence: 99%

“…At TEA/MA ≥ 2 eq, TEA catalyzes the hydrolysis of the anhydride compared to nucleophilic acyl substitution reaction, favoring the formation of methacrylic acid rather than grafting on the alginate backbone and resulting in lower DM. 23 In addition, a large excess of MA is used to achieve a higher DM. A logarithmic increase is observed until a plateau is achieved due to the steric hindrance caused by the grafted methacrylic moieties.…”

Section: Sodium Alginate Chemical Modificationmentioning

confidence: 99%

Dual Cross-Linked Stimuli-Responsive Alginate-Based Hydrogels

Habib,

Berthalon,

Leclercq

et al. 2024

Biomacromolecules

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Sodium alginate with different molecular weights (55, 170, and 320 kg mol −1 ) were chemically modified by grafting methacrylic moieties onto the hydroxyl groups of the alginate backbone. The methacrylation was optimized to obtain different degrees of modification. Chemically cross-linked hydrogels were obtained following UV-light irradiation in the presence of a photoinitiator. The swelling behavior and the mechanical properties were observed to depend on both the degree of methacrylation and the alginate molecular weight. Due to the chain entanglement present in highviscosity sodium alginate, lower degrees of modification were required to tune the hydrogel properties. Moreover, in the presence of Ca 2+ , secondary cross-linking was introduced by the coordination of the alginate guluronate moieties with the Ca 2+ ions. The addition of this secondary cross-linking caused fast volume shrinkage and a reinforcement of the mechanical properties. The secondary cross-linking was reversible, and the hydrogels regained their original shape for at least three cycles. Additionally, the dual cross-linked network can be used to induce adhesion between hydrogels and serve as a building block for self-folding actuators.

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“…Their report was followed by others, where triphenylimidazole‐derived esters and related compounds, such as acid chlorides and amides, were applied as FL or CL probes, being of special interest for enzyme activity determination and drug‐binding site characterization . The fact that 1 and 2 are both markedly fluorescent make them promising for studying ester decomposition pathways, especially using spectroscopic methods . In order to avoid the need of using chromatographic separation and quantification techniques, we have explored the FL emission of both reactant and product to study the decomposition of 1 in basic alcoholic media.…”

Section: Introductionmentioning

confidence: 99%

The decomposition of triphenylimidazole‐para‐acetate follows specific base catalysis and can be conveniently followed by fluorescence

et al. 2019

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The kinetics of the decomposition reaction of 4-(4,5-diphenyl-1H-imidazol-2-yl)phenyl acetate (1) in basic alcoholic media was investigated, using a simple fluorescence (FL) spectrophotometric procedure. The process was conveniently studied using FL, since the triphenylimidazole-derived ester 1 and its reaction products (the corresponding phenol 2 and phenolate 2 − ) are all highly fluorescent (Φ FL > 37%). By carefully selecting excitation and emission wavelengths, observed rate constants k 1 in the order of 10 −3 to 10 −2 s −1 were obtained from either reactant consumption (λ ex = 300 nm, λ em = 400 nm) or product formation (λ ex = 350 nm, λ em = 475 nm); these were shown to be kinetically equivalent. Intensity-decay time profiles also gave a residual FL intensity parameter, shown to be associated to the distribution of produced species 2 and 2 − , according to the basicity of the medium. Studying the reaction in both methanol (MeOH) and isopropanol (iPrOH), upon addition of HO − , provided evidence that the solvent's conjugate base is the active nucleophilic species.When different bases were used (tBuO − , HO − , DBU and TEA), bimolecular rate constants k bim ranging from 4.5 to 6.5 L mol −1 s −1 were obtained, which proved to be non-dependent on the base pK aH , suggesting specific base catalysis for the decomposition of 1 in alcoholic media. KEYWORDS imidazole, kineticslight emissionlophine, rate constant 1 | INTRODUCTIONThe triphenylimidazole structural framework has been intensely studied throughout the years, by many different research groups, due to its fluorescence (FL) [1][2][3][4][5][6][7][8][9] and chemiluminescence (CL) [10][11][12][13][14][15][16][17][18][19][20][21][22] properties. The typical direct CL of 2,4,5-triphenylimidazole (also known as lophine) with oxygen in an alkaline media, first described by Radziszewski in 1877, [23] was studied mainly to elucidate its reaction mechanism. [11][12][13][18][19][20][21][22]24] However, lophine and its derivatives were also applied in other CL systems, being used as activators of the peroxyoxalate reaction [10] or enhancers of the luminol transformation. [25][26][27] In part, the vast array of application of these molecules, from FL to CL measurements, depends on the high FL quantum yields (Φ FL > 0.1) presented by them. [1][2][3][4][5][6][7][8][9][10]17,[24][25][26][27] In 1993, Kuroda et al. reported that triphenylimidazole-para-acetate (1, IUPAC name 4-(4,5-diphenyl-1H-imidazol-2-yl)phenyl acetate), as well as another three ester analogs based on pertinent fatty acids, could be applied on the evaluation of lipase activity through FL measurements. [8] Although ester 1 itself was not the most suitable for interaction with the lipase, it was primarily used to define the methodology for activity determination. Briefly, the method consisted on hydrolyzing the ester with the enzyme, followed by separation and FL

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A comparative study on the hydrolysis of acetic anhydride and N,N-dimethylformamide: Kinetic isotope effect, transition-state structure, polarity, and solvent effect

Cited by 8 publications

References 36 publications

Palladium/iodide catalyzed oxidative carbonylation of aniline to diphenylurea: Effect of ppm amounts of iron salts

Palladium/iodide catalyzed oxidative carbonylation of aniline to diphenylurea: Effect of ppm amounts of iron salts

Dual Cross-Linked Stimuli-Responsive Alginate-Based Hydrogels

The decomposition of triphenylimidazole‐para‐acetate follows specific base catalysis and can be conveniently followed by fluorescence

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