Kinetic and thermodynamic study of substituent effect on the Claisen rearrangement of para-substituted SI aryl ether: a Hammett study via DFT
محورهای موضوعی : Journal of Physical & Theoretical Chemistry
S. R. Emamian
1
(-)
M. R. Zardoost
2
(-)
K. Zare
3
(-)
E. Zahedi
4
(-)
H. Aghaie
5
(-)
کلید واژه: Hammett, Density functional theory, Substutuent effect, Claisen re, Ally! aryl ether,
چکیده مقاله :
In order to find the susceptibility of the Claisen rearrangement and next proton shift reaction of ally) aryl etherto the substiment effects in pan position, the kinetic and the:rmodynamie parameters are calculated at The33 LTP level using 6-3110. b asis set. The calculated activation energies for the rearrangements and protonshift reactions are around 3133 kcaUmol and 52.16 kcal/mol, nap.. lively. Negative values for the activationentropy confirm the concerted mechanign for the Claisen rearrangement and proton shift reaction. TheHammett p value of -1.3433 obtained in Claigen rearrangement. Negative Hammett p value indicate, that theelectron donating groups slightly increase the rate of Claisen rearrangement. Positive Hammett p value (2.5132)for proton shift reaction indicates that electron withdrawing coups increase the rate of reaciion.
