Kinetic and Mechanistic Insights into the Pathway Leading to Cyclic Crystalline Phosphorus Ylide Formation in the Presence of 3-Chloropentane-2,4-dione: Theoretical and Stopped-Flow Approaches

Abstract

In this work, three speculative mechanisms of the reaction between triphenylphosphine and dimethyl acetylendicarboxylate in the presence of 3‐chloropentane‐2,4‐dione were energetically and thermodynamically developed using quantum mechanical calculations and were profoundly compared with stopped‐flow and UV spectrophotometry approaches. The third speculative mechanism that led to the five‐membered ring structure was experimentally and theoretically favorable. The five‐membered ring structure of product was characterized by X‐ray crystallographic data. Also, steps 1 and 2 of the third mechanism were determined as fast and rate‐determining steps, respectively. The experimental kinetic evidence of the formation and decay of intermediate in steps 1 and 2 (fast and rate‐determining steps, respectively) was compatible with theoretical data. Experimental kinetic data were recognized for overall reaction along with activation parameters for fast and rate‐determining steps of the reaction. Theoretical kinetic data (k and Ea) and activation parameters (ΔG≠, ΔS,≠ and ΔH≠) were calculated for each step and overall reactions.

An experimental investigation of substituent effects on the formation of 2,3-dihydroquinazolin-4(1H)-ones: a kinetic study

“…A number of methods have been developed to obtain experimental kinetic data and to analyze the data to arrive at a correct interpretation of the reaction. Numerous kinetic researches over a large area of different reactions have previously been reported using the UV/vis technique . The main purpose of this study is to obtain comprehensive overview on kinetic behavior of the reaction in Scheme along with an investigation of action of particular substituents in altering the rate and kinetic parameters of reaction.…”

A Thermodynamic and Kinetic Insight into the Pathways Leading to a Highly Functionalized Ketenimine: A Computational Study

“…Experimental methods have many instrumental limitations such as trapping the intermediates or transition states (TSs) in confirming the mechanism from which the reactions proceed. Computational methods are already an extremely valuable tool in examining reaction mechanisms . During past few years, density functional theory (DFT) based methods have been widely accepted by computational chemistry community as a reliably practical tool for the study of chemical reactions, especially, for large systems .…”

Investigation of the Mannich reaction for generating a β-aminoketone: further treatment of kinetic results

“…The progress of the reaction among benzaldehyde 1, aniline 2 and acetophenone compound 3 in the presence of sodium acetate (Scheme 1) was studied by the UV-vis spectrophotometer similar to a previous procedure which was reported earlier [44][45][46][47][48][49][50][51]. Optimal concentrations of each reactant for kinetic study are summarized in Table 1.…”