A DFT study on the effect of position of functional group on the kinetics and mechanism of 1,3-dipolar cycloaddition of benzonitrile oxide and dihydrofuran

A theoretical study on the effect of position of functional groups on the kinetics and mechanism of Cycloaddition of benzonitrile oxide and Dihydrofuran was performed using DFT methods at the B3LYP level of the theory with 6-31G (d, p) basis set at 298.15K. Equilibrium molecular geometries and harmonic vibrational frequencies of the reactants, transition state and product were calculated. Natural bond orbital analysis was used to analysis charge changes on the atoms during the reaction. Thermodynamic and kinetic parameters of the reaction were investigated. Solvent effect on the kinetic and thermodynamic parameters of the reaction was investigated. Non polar solvent enhances the rate. But the reaction in polar solvent was slower than gas phase. These calculations indicated that the reaction proceeds through a synchronous concerted mechanism. Putting the methyl functional group on the phenyl ring changes the reaction rate, but changing the position of it in ortho, meta or para position has no change in the rate.