We report a theoretical investigation of b-elimination reactions in systems activated by the pyridine ring. The investigated reaction, the acetohydroxamate-induced b-elimination in protonated N-[2-(2-pyri- dyl)ethyl]quinuclidinium, offers a unique opportunity to test computational methodologies since detailed kinetic experimental data are available. We calculated the pKas of the acetohydroxamic acid and the sub- strate and thoroughly characterized the reactive free-energy profile. The reaction proceeds via a stable carbanion intermediate. Except a discrepancy in the reproduction of the pKa of the acetohydroxamic acid, the calculated free-energy profile is in excellent agreement with the experiment, showing the general reli- ability of the present approach.
A DFT investigation of base-catalyzed β-elimination reactions in water solution for systems activated by the pyridine ring: Theory vs. Experiment
MOSCONI, EDOARDO;F. De Angelis;TARANTELLI, Francesco;ALUNNI, Sergio;SGAMELLOTTI, Antonio
2008
Abstract
We report a theoretical investigation of b-elimination reactions in systems activated by the pyridine ring. The investigated reaction, the acetohydroxamate-induced b-elimination in protonated N-[2-(2-pyri- dyl)ethyl]quinuclidinium, offers a unique opportunity to test computational methodologies since detailed kinetic experimental data are available. We calculated the pKas of the acetohydroxamic acid and the sub- strate and thoroughly characterized the reactive free-energy profile. The reaction proceeds via a stable carbanion intermediate. Except a discrepancy in the reproduction of the pKa of the acetohydroxamic acid, the calculated free-energy profile is in excellent agreement with the experiment, showing the general reli- ability of the present approach.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
