22113-51-5

Upstream product

• 20274-94-6 (2R,3S,4S,5R,6S)-2-Hydroxymethyl-6-p-tolyloxy-tetrahydro-pyran-3,4,5-triol 
• 106-44-5 p-cresol 
• 71-50-1 acetate 
• 114444-46-1 C₁₄H₁₃NO 
• 120-12-7 anthracene radical anion 
• 140-39-6 1-acetoxy-4-methylbenzene 
• 3174-48-9 p-methylphenoxyl radical 
• 14998-27-7 chlorite 
• 3229-70-7 phenolate 
• 29368-59-0 p-methoxyphenolate 
• 58-15-1 aminopyrine 
• 2005-11-0 p-cresyl fluorene-9-carboxylate 
• 10024-57-4 4-methylphenyl laurate 
• 106-50-3 1,4-phenylenediamine 

Downstream Products

• 3174-48-9 p-methylphenoxyl radical 
• 29368-59-0 p-methoxyphenolate 
• 140-39-6 1-acetoxy-4-methylbenzene 
• 16554-54-4 3-nitrophenolate anion 
• 1864-97-7 p-tolyl formate 
• 14609-74-6 p-nitrophenolate 
• 94089-33-5 Trichlormethylhydroperoxid 
• 106-44-5 p-cresol 
• 114444-46-1 C₁₄H₁₃NO 
• 140245-71-2 1,3,4-trichloro-5,5-dimethoxy-2-(p-methylphenoxy)cyclopentadiene 
• 940-64-7 2-(4-methylphenoxy)acetic acid 
• 26330-85-8 4-Methyl-benzenethiol anion 
• 20217-24-7 recorcinol monoanion 
• 21713-53-1 4-methyl-o-phenyl phenyl(phenyl)phosphinate 

Relevant academic research and scientific papers

Kinetic study on alkaline hydrolysis of Y-substituted phenyl picolinates: Effects of modification of nonleaving group from benzoyl to picolinyl on reactivity and reaction mechanism

Second-order rate constants (kOH-) for alkaline hydrolysis of Y-substituted phenyl picolinates (6a-6i) have been measured spectrophotometrically. A linear Bronsted-type plot is obtained with βlg = -0.34, which is typical for reactions reported previously to proceed through a stepwise mechanism with formation of an addition intermediate being the rate-determining step (RDS). However, σYo constants result in a much poorer Hammett correlation than σY- constants. Furthermore, the Yukawa-Tsuno plot exhibits an excellent linear correlation with ρY = 0.82 and r = 0.72, indicating that a negative charge develops partially on the O atom of the leaving group in the RDS. Thus, the reactions have been concluded to proceed through a forced concerted mechanism with a highly unstable intermediate 7. Comparison of the current kinetic data with those reported previously for the corresponding reactions of Y-substituted phenyl benzoates has revealed that modification of the nonleaving group from benzoyl to picolinyl causes not only an increase in reactivity but also a change in the reaction mechanism (i.e., from a stepwise mechanism to a forced concerted pathway).

Reactions of [aryloxy(phenyl)carbene]pentacarbonylchromium(0) complexes with thiolate ions. Decreasing reactivity with increasing basicity of the nucleophile

(Chemical Equation Presented) A kinetic study of the reactions of thiolate ions with three Fischer-type [aryloxy(phenyl)carbene]-pentacarbonyl chromium(0) complexes in 50% MeCN-50% water (v/v) is reported. Bronsted plots of the second-order rate constants are biphasic with an initial steep rise for weakly basic thiolate ions (βnuc ≈ 1.0) followed by a slightly descending leg with a negative slope (βnuc ≈ -0.2) for strongly basic thiolate ions. This indicates a change from rate-limiting leaving group departure at low pKaRSH to rate-limiting nucleophilic attachment at high pKaRSH. The negative βnuc values result from a combination of minimal progress of C-S bond formation at the transition state and the requirement for partial desolvation of the nucleophile before it enters the transition state. Possible factors that may affect the degree of bond formation in reactions of Fischer carbene complexes as well as reactions of other unsaturated electrophiles with thiolate ions are discussed.

Kinetics and mechanistic study of the reaction of cyclic anhydrides with substituted phenols. Structure-reactivity relationships

(Chemical Equation Presented) The kinetic of the reactions of phthalic and maleic anhydrides with different substituted phenols (Z-PhOH with Z = H, m-CH3, p-CH3, m-Cl, p-Cl, and m-CN) were studied in aqueous solution. Two kinetic processes well separated in time were observed. The fast one is attributed to the formation of the aryl ester in equilibrium with the anhydride and allows the determination of the rate of nucleophilic attack of the phenol on the anhydride (k-A). From the slow kinetic process, the equilibrium constant for this reaction was determined. The Broensted-type plots for the nucleophilic attack of substituted phenols on the anhydrides were linear with slopes βNuc of 0.45 and 0.56 for phthalic and maleic anhydride, respectively. The results are consistent with a mechanism involving rate-determining nucleophilic attack and also with a concerted mechanism. The calculated effective charge on the atoms involved in the reactions and the Broensted β values are consistent with a mechanism involving a concerted or enforced concerted mechanism where a tetrahedral intermediate with significant lifetime is not formed along the reaction coordinate. The latter mechanism is preferred over the stepwise process.

Mechanistic change in the reactivity of substituted phenyl acetates over phenyl thiolacetates toward imidazole in aqueous phase

The kinetics of aminolysis of several substituted phenyl acetates by imidazole is studied in aqueous medium at 20°C and an ionic strength of 0.1 M (KCl). By following the leaving groups spectrophotometrically (λ max = 272-401 nm), under excess free imidazole, pseudo-first-order rate constants (κobs) are obtained. For the esters with good nucleofuges, the reaction follows clean second-order kinetics and the plots of (κobs - κH) against free imidazole concentration are linear at constant pH. The macroscopic nucleophilic substitution rate constants (κN) are obtained as the slopes of these plots and found to be pH independent. For the esters with poor nucleofuges, a rate dependence on more than first power of the free imidazole and a linear dependence of κ′2 on free imidazole is observed. Accordingly, the microscopic rate constants for the assisted paths viz. κga and κgb have been disseminated besides for simple bimolecular attack. The Broensted-type plots and Hammett plots were constructed whose slope values are consistent with a stepwise mechanism through a bipolar tetrahedral addition intermediate whose formation or breakdown being rate determining for various paths. Comparison of this reaction of oxyesters with the earlier reported works on similar reaction of analogue thiolesters under identical reaction conditions showed remarkable mechanistic differences which are discussed in detail. The discussion is extended to include the details on previously studied ammonolysis of these two types of esters wherein thiolesters showed differed reactivity than that reported in the present study.

Curved Hammett Plot in Alkaline Hydrolysis of O-Aryl Thionobenzoates: Change in Rate-Determining Step versus Ground-State Stabilization

Second-order rate constants have been measured for alkaline hydrolysis of O-aryl thionobenzoates (X-C6H4-CS-OC6H 4-Y) in 80 mol % H2O-20 mol % DMSO at 25.0 ± 0.1 °C. The Hammett plot for the reaction of O-4-nitrophenyl X-substituted thionobenzoates (X-C6H4-CS-OC6H 4-NO2, 1a-e) exhibits a downward curvature. However, a possible traditional explanation in terms of a change in the rate-determining step (RDS) has been considered but rejected. The proposed explanation involves stabilization of the ground-state (GS) through-resonance interaction between the electron-donating substituent X and the thionocarbonyl functionality on the basis of the linear Yukawa-Tsuno plot obtained for the same reaction. The Bronsted-type plot for the reaction of O-aryl thionobenzoates (C 6H5-CS-OC6H4-Y, 2a-i) is linear but exhibits many scattered points with a small βlg, (-0.35). The Hammett plot for the same reaction shows rather poor correlation with σ- constants but much better correlation with σ° constants. The alkaline hydrolysis of O-aryl thionobenzoates (1a-e and 2a-i) has been proposed to proceed through an addition intermediate in which bond formation is the RDS.

Reinterpretation of curved hammett plots in reaction of nucleophiles with aryl benzoates: Change in rate-determining step or mechanism versus ground-state stabilization

A kinetic study is reported for the reaction of the anionic nucleophiles OH-, CN-, and N3- with aryl benzoates containing substituents on the benzoyl as well as the aryloxy moiety, in 80 mol % H2O-20 mol % dimethyl sulfoxide at 25.0 °C. Hammett log k vs σ plots for these systems are consistently nonlinear. However, a possible traditional explanation in terms of a mechanism involving a tetrahedral intermediate with curvature resulting from a change in rate-determining step is considered but rejected. The proposed explanation involves ground-state stabilization through resonance interaction between the benzoyl substituent and the electrophilic carbonyl center in the two-stage mechanism. Accordingly, the data are nicely accommodated on the basis of the Yukawa-Tsuno equation, which gives linear plots for all three nuceophiles. Literature reports of the mechanism of acyl transfer processes are reconsidered in this light.

Kinetics and mechanism of phosphate-catalyzed hydrolysis of benzoate esters: Comparison with nucleophilic catalysis by imidazole and o-iodosobenzoate

Phosphate-catalyzed hydrolysis of 2,4-dinitrophenyl 4-X-benzoate, and 3- or 4-Y-phenyl 3,5-dinitrobenzoates, where X and Y are substituents, has been studied spectrophotometrically. The following conclusions are based on catalytic rate constants, solvent

Acid dissociation constants of phenols and reaction mechanism for the reactions of substituted phenyl benzoates with phenoxide anions in absolute ethanol

Acid dissociation constants of 10 substituted phenols have been measured by a kinetic method together with second-order rate constants for the reactions of aryl benzoates (X-C6H4CO-OC6H4-Y) with Z-substituted phenoxide (Z-C6H4O-) and EtO- in absolute ethanol at 25.0 ± 0.1°C. The kinetic results support a stepwise mechanism for the present acyl-transfer reaction.

Reduction potentials and kinetics of electron transfer reactions of phenylthiyl radicals: Comparisons with phenoxyl radicals

The reduction potentials relative to the standard hydrogen electrode (SHE) for a number of para-substituted phenylthiyl radicals (Eo(p-XC6H4S./p-XC6H 4S-)) have been derived from pulse radiolytic studies of electron transfer equilibria which compare their values to those of radicals of known reduction potentials. A ladder combining the reduction potentials for both phenylthiyl and phenoxyl radicals has been established. These reduction potentials have been shown to be self-consistent and are intermediate between those of p-benzosemiquinone radical anion at 0.02 V and phenoxyl radical at 0.79 V. The reduction potential decreases as the electron donating power of the para substituent rises. The substituent effect is, however, much weaker for the phenylthiyl radicals than for their oxygen analogs. These observations demonstrate that the electronic interaction between the sulfur atoms and the aromatic ring system is much less than that which occurs with oxygen atoms. Examination of the rates of electron transfer in terms of the Marcus theory indicates that the reorganization energies of both p-XC6H4O. and p-XC6H4S. radicals are similarly affected by H, CH3, and CH3O substitution. However, the reorganization energies increase substantially for H2N and O- para substituents with the effect being much less for the p-XC6H4S. radicals than for the p-XC6H4O. radicals. These observations are in accord with structural information from spectroscopic and theoretical studies of the radicals which show that in the latter system the substituent groups interact strongly with the aromatic π system.