Theoretical, NMR Study, Kinetics and a Mechanistic Investigation of the Reaction between Triphenylphosphine, Dialkyl Acetylenedicarboxylates and 2-Aminothiophenol

Habibi‐Khorassani, Sayyed Mostafa; Ebrahimi, Ali; Maghsoodlou, Malek Taher; Zakarianezhad, Mohammad; Ghasempour, Hojjat; Ghahghayi, Zahra

doi:10.2174/138527211794518844

Cited by 21 publications

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“…High dipole moment of the transition state structure relative to the reactants caused the transition state to be considerably more unstable than the reactants and increased the transition barrier. [22,23] In this reaction, investigation of the dipole moment (Table S1) indicates that structures Ts1 and I1 have a lower dipole moment than the total dipole moment of the reactants. Stronger interaction of the polar solvent (dichloromethane) with the reactants makes them more stable than the transition state and increased the transition barrier of the first step.…”

Section: Aim and Nbo Analysismentioning

confidence: 94%

Mechanistic investigation of the reaction of thiourea with dialkyl acetylenedicarboxylates: a theoretical study

Zakarianezhad

dadi

2015

Journal of Sulfur Chemistry

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In this work, mechanistic investigation of the addition-cyclization reaction between thiourea (TU) and dialkyl acetylenedicarboxylate (DAAD) was made theoretically with the B3LYP method using a 6-311++G(2d,2p) basis set. In order to investigate the effect of substituted alkyl groups, the reaction was evaluated in the presence of dimethyl acetylenedicarboxylate, diethyl acetylenedicarboxylate and di-tert-butyl acetylenedicarboxylate. To evaluate the effect of structure and dielectric constant of the solvent, all structures were optimized in different solvent phases such as dichloromethane and acetone at the B3LYP/6-311++G(2d,2p) level of theory. Different orientations of alkyl groups make different kinetic paths. Results indicated that the reaction mechanism did not change with different orientations of COOMe, COOEt or COOtBu groups, but caused significant changes in the potential energy surfaces of the reaction coordinate. The reaction product (alkyl E-2-(2-imino-4-oxo-1,3-thiazolane-5-yliden) acetates) can be converted to different tautomeric forms in two proton transfer processes. So, in order to investigate the effect of different substituted alkyl groups, intermolecular proton transfer in the product was investigated both in gas phase and in the presence of methanol, ethanol and tert-butanol molecules as a bridge to facilitate the proton transfer process.

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Section: Aim and Nbo Analysismentioning

confidence: 94%

Mechanistic investigation of the reaction of thiourea with dialkyl acetylenedicarboxylates: a theoretical study

Zakarianezhad

dadi

2015

Journal of Sulfur Chemistry

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“…Some phosphorus ylides are obtained in excellent yields from 1:1:1 addition reactions between triphenylphosphine (TPP), dialkyl acetylendicarboxylates in the presence of C–H, S–H, N–H or O–H heterocycles. In recent years, we have tried to develop synthesis along with experimental and theoretical studies on the kinetics and reaction mechanism of phosphorus ylides . All these reactions afforded an intermediate in the step 1; however, there was no experimental evidence to prove it.…”

Section: Introductionmentioning

confidence: 99%

Kinetic spectrophotometric approach to the reaction mechanism of pyrrole phosphorus ylide formation based on monitoring the zwitterionic intermediate by using the stopped-flow technique

Shahraki

Habibi‐Khorassani

2015

J. Phys. Org. Chem.

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a For the first time, an experimental evidence for the existence of a zwitterionic intermediate (ZI) on reaction mechanism of a synthesized phosphorous ylide has been presented in aqueous-organic solvent mixtures by using the stopped-flow technique. Spectral analyses confirmed the existence of ZI in the step 1 of the reaction. The step 1 that was recognized as a fast step included the formation and decay of the ZI. Pro-K analyzer detected six species according to the proposed mechanism. Also, the kinetics of the reaction has been studied by the UV-Vis spectrophotometer. The value of rate constants for the step 1 (k 1 and k À1 ), step 2 (k 2 ) and overall (k ovr ), and associated activation parameters of the reaction were determined.

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“…The activation energy and the other related thermodynamic parameters for the reaction are experimentally determined through the Arrhenius and Eyring equations. Numerous kinetic investigations over a large area of different reactions have previously been reported using the UV/Vis technique [34][35][36][37][38][39][40][41][42][43][44][45][46][47].…”

Section: Introductionmentioning

confidence: 99%

Full Kinetics and a Mechanistic Investigation of the Green Protocol for Synthesis of β-Aminoketone in the Presence of Saccharose as a Catalyst by a One-Pot Three-Component Reaction

Habibi‐Khorassani

Maghsoodlou

Shahraki

et al. 2014

Advances in Physical Chemistry

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For the first time, in a green protocol, an investigation of the kinetics and mechanism of the reaction between benzaldehyde 1, 4-chloroanilinne 2, and acetophenone 3 compounds in the presence of saccharose as a catalyst was performed for generating -aminoketone. For determining the kinetic parameters, the reaction was monitored by using the UV/Vis spectrophotometry technique. The second order rate constant ( 1 ) was automatically calculated by the standard equations contained within the program. In the studied temperature range, the second order rate constant (ln 1 , ln 1 / ) depended on reciprocal temperature that was in good consistent with Arrhenius and Eyring equations, respectively. These data provided the suitable plots for calculating the activation energy and parameters (Ea, Δ ‡ , Δ ‡ , and Δ ‡ ) of the reaction. Furthermore, useful information was obtained from studying the effects of solvent, concentration, and catalyst on the reaction mechanism. The results showed that the first step of the reaction mechanism is a rate determining step (RDS). The obtained experimental data and also the steady state assumption confirmed the proposed mechanism.

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Theoretical, NMR Study, Kinetics and a Mechanistic Investigation of the Reaction between Triphenylphosphine, Dialkyl Acetylenedicarboxylates and 2-Aminothiophenol

Cited by 21 publications

References 0 publications

Mechanistic investigation of the reaction of thiourea with dialkyl acetylenedicarboxylates: a theoretical study

Mechanistic investigation of the reaction of thiourea with dialkyl acetylenedicarboxylates: a theoretical study

Kinetic spectrophotometric approach to the reaction mechanism of pyrrole phosphorus ylide formation based on monitoring the zwitterionic intermediate by using the stopped-flow technique

Full Kinetics and a Mechanistic Investigation of the Green Protocol for Synthesis of β-Aminoketone in the Presence of Saccharose as a Catalyst by a One-Pot Three-Component Reaction

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