Successful computational modeling of isobornyl chloride ion-pair mechanisms.
Along with the directly related Wagner-Meerwein camphene hydrochloride-isobornyl chloride rearrangement, the racemization of isobornyl chloride involves intermediate carbocation-anion ion pairs; both processes have become mechanistic icons in organic chemistry. The two known racemization pathways, involving either a hydride transfer or a methyl migration, are observed to be concurrent. However, prior quantitative computational modeling has not been able to reproduce the fine kinetic balance of these processes. We demonstrate that a density functional approach, which includes two explicit solvent molecules embedded in a continuum solvent field, coupled with full geometric optimization using smoothed solvent cavities and free energy calculation, yields results in accord with experiment. Alternative racemization routes also have been explored.
Kong
Jing
J
Key Laboratory for Green Chemical Technology of Ministry of Education, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
Schleyer
Paul v R
Pv
Rzepa
Henry S
HS