74738-56-0Relevant academic research and scientific papers
Transesterification of (hetero)aryl esters with phenols by an Earth-abundant metal catalyst
Chen, Jianxia,Namila,Bai, Chaolumen,Baiyin, Menghe,Agula, Bao,Bao, Yong-Sheng
, p. 25168 - 25176 (2018/07/29)
Readily available and inexpensive Earth-abundant alkali metal species are used as efficient catalysts for the transesterification of aryl or heteroaryl esters with phenols which is a challenging and underdeveloped transformation. The simple conditions and the use of heterogeneous alkali metal catalyst make this protocol very environmentally friendly and practical. This reaction fills in the missing part in transesterification reaction of phenols and provides an efficient approach to aryl esters, which are widely used in the synthetic and pharmaceutical industry.
Kinetic study on nucleophilic substitution reactions of 4-Nitrophenyl X-Substituted-2-Methylbenzoates with cyclic secondary amines in acetonitrile: Reaction mechanism and failure of reactivity-selectivity principle
Lee, Ji-Youn,Kim, Min-Young,Um, Ik-Hwan
, p. 93 - 97 (2014/02/14)
A kinetic study is reported on nucleophilic substitution reactions of 4-nitrophenyl X-substituted-2-methylbenzoates (5a-e) with a series of cyclic secondary amines in MeCN at 25.0 ± 0.1 °C. The Hammett plots for the aminolysis of 5a-e are nonlinear, e.g., substrates possessing an electron-donating group (EDG) in the benzoyl moiety deviate negatively from the linear line composed of substrates bearing no EDG. In contrast, the Yukawa-Tsuno plots for the same reactions exhibit excellent linear correlations with pX = 0.30-0.59 and r = 0.90-1.15, indicating that the nonlinear Hammett plots are caused by stabilization of the substrates possessing an EDG through resonance interactions but are not due to a change in the rate-determining step (RDS). The Bronsted-type plots are linear with βnuc = 0.66-0.82. Thus, the aminolysis of 5a-e has been suggested to proceed through a stepwise mechanism in which departure of the leaving group occurs at the RDS. The PX and βnuc values for the aminolysis of 5a-e increase as the reactivity of the substrates and amines increases, indicating that the reactivity-selectivity principle is not applicable to the current reactions.
Kinetic study on nucleophilic displacement reactions of y-substituted-phenyl 2-methylbenzoates with cyclic secondary amines in acetonitrile: Effects of modification of 2-meo in benzoyl moiety by 2-me on reactivity and reaction mechanism
Lee, Ji-Youn,Kim, Mi-Yeon,Um, Ik-Hwan
, p. 3795 - 3799 (2014/01/17)
The second-order rate constants (kN) have been measured spectrophotometrically for nucleophilic substitution reactions of Y-substituted-phenyl 2-methylbenzoates (6a-e) with a series of cyclic secondary amines in MeCN at 25.0 ± 0.1 oC. Comparison of the kN values for the reactions of 4-nitrophenyl 2-methylbenzoate (6d) with those reported previously for the corresponding reactions of 4-nitrophenyl 2-methoxybenzoate (5) reveals that 6d is significantly less reactive than 5, indicating that modification of 2-MeO in the benzoyl moiety of 5 by 2-Me (i.e., 5 ? 6d) causes a significant decrease in reactivity. This supports our previous report that aminolysis of 5 proceeds through a six-membered cyclic intermediate, which is highly stabilized through intramolecular H-bonding interactions. The Bronsted-type plot for the reactions of 6d with a series of cyclic secondary amines is linear with ssnuc = 0.71, which appears to be a lower limit of ssnuc for a stepwise mechanism with breakdown of an intermediate (T±) being rate-determining step (RDS). The Bronsted-type plot for the reactions of 6a-e with piperidine is curved, i.e., the slope of Bronsted-type plot (sslg) decreases from -1.05 to -0.41 as the leavinggroup basicity decreases. The nonlinear Bronsted-type plot has been taken as evidence for a stepwise mechanism with a change in RDS (e.g., from the k2 step to the k1 process as the leaving-group basicity decreases). Dissection of kN into the microscopic rate constants associated with the reactions of 6a-e with piperidine (e.g.,k1 and k2/k-1 ratio) also supports the proposed mechanism.
Ruthenium/NHC-catalyzed tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols
Zhang, Di,Pan, Changduo
experimental part, p. 41 - 45 (2012/06/18)
An efficient methodology to access benzoate derivatives via tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols catalyzed by ruthenium/NHC was developed. This operationally simple one-pot process uses O2 as the clean oxidant, producing esters in good to excellent yields.
Palladium/NHC-catalyzed tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols
Luo, Fang,Pan, Changduo,Cheng, Jiang,Chen, Fan
supporting information; experimental part, p. 5878 - 5882 (2011/09/12)
A palladium/NHC-catalyzed tandem benzylic oxidation/oxidative esterification of benzylic alcohols with phenols to access aryl benzoate derivatives is described. The procedure tolerates a series of functional groups, such as methoxy, nitro, cyano, chloro, fluoro and bromo groups. Thus, it represents a practically alternative method to access aryl benzoate derivatives.
Palladium/NHC-catalyzed oxidative esterification of aldehydes with phenols
Zhang, Manli,Zhang, Shouhui,Zhang, Guoying,Chen, Fan,Cheng, Jiang
experimental part, p. 2480 - 2483 (2011/05/16)
A palladium-catalyzed oxidative esterification of aldehydes with phenols is described, using air as the clean oxidant. This reaction tolerates many functional groups, providing esters with yields ranging from moderate to excellent.
Effect of o-methyl group on rate, mechanism, and resonance contribution: Aminolysis of Y-substituted phenyl X-substituted 2-methylbenzoates
Um, Ik-Hwan,Lee, Ji-Youn,Lee, Hai Whang,Nagano, Yoshiya,Fujio, Mizue,Tsuno, Yuho
, p. 4980 - 4987 (2007/10/03)
Second-order rate constants have been determined spectrophotometrically for the reactions of 4-nitrophenyl X-substituted 2-methylbenzoates (2a-e) and Y-substituted phenyl 2-methylbenzoates (3a-e) with alicyclic secondary amines in 80 mol % H2O/20 mol % DMSO at 25.0 ± 0.1 °C. The o-methyl group in the benzoyl moiety of 2a-e retards the reaction rate but does not influence the reaction mechanism. The Hammett plots for the reactions of 2a-e are nonlinear, while the corresponding Yukawa-Tsuno plots are linear with large r values (1.06-1.70). The linear Yukawa-Tsuno plots suggest that stabilization of the ground-state through resonance interaction between the electron donating substituent X and the carbonyl group is responsible for the nonlinear Hammett plots, while the large r values imply that the ground-state resonance interaction is significant. The reactions of 2a-e resulted in smaller ρX values but larger r values than the corresponding reactions of 4-nitrophenyl X-substituted benzoates (1a-e). The small ρX value for the reactions of 2a-e (e.g., ρX = 0.22) is suggested to be responsible for the large r value (e.g., r = 1.70). The reactions of 3a-e with piperidine are proposed to proceed in a stepwise manner with a change in the rate-determining step on the basis of the curved Bronsted-type plot obtained. Microscopic rate constants associated with the reactions of 3a-e are also consistent with the proposed mechanism.
EFFECT OF NEIGHBORING PYRIDINIUM GROUPS ON THE BASIC HYDROLYSIS OF ARYLBENZOATE ESTERS
Engbersen, J. F. J.,Geurtsen, G.,Bie, D. A. De,Plas, H. C. Van Der
, p. 1795 - 1802 (2007/10/02)
Arylbenzoate esters with a quaternary pyridinium group ortho to the ester function exhibit enhanced reactivity towards basic hydrolysis relative to their para analogs in the order pyridinium 4-aminocarbonylpyridinium 3-aminocarbonylpyridinium 3-aminocarbonylquinolium.In contrast, a trimethylammonium group in the ortho position shows a decelerating effect relative to the para analog.It is concluded that the catalytic effect of a neighboring pyridinium group is based upon interaction of the negatively charged transition state of ester hydrolysis with the electron deficient ?-system of the pyridinium ring.For the p-methoxyphenolate ester containing the 3-aminocarbonylpyridinium group in the ortho position this interaction leads to a change in mechanism from rate limiting hydroxide ion attack to hydroxide ion catalyzed expulsion of the leaving group as became apparent from deviation of the Hammett plot and second-order dependence on OH(1-) concentration.For the p-nitrophenolate ester it was observed that decrease of the solvent polarity by addition of dioxane results in an increase of the rate of hydrolysis and a marked increase of the neighboring group effect.
Catalytic Mechanisms of Acyl Transfer Reactions in Dipolar Aprotic Media. 2. Electrophilic Activation of the Carbonyl Group by Quaternary Alkylammonium and Imidazolium Functions
Hajdu, Joseph,Smith, Georgianna M.
, p. 6192 - 6197 (2007/10/02)
Crown ether solvated potassium acetate in dipolar aprotic media readily converts p-nitrophenyl o-toluate to the corresponding acetyltoluyl mixed anhydride.The reaction proceeds at room temperature in quantitative yield.The rate of acyl transfer is 0.0118
