Isotope effects in nucleophilic substitution reactions. IV. The effect of changing a substituent at the α carbon on the structure of S<sub>N</sub>2 transition states
作者:Kenneth Charles Westaway、Zbigniew Waszczylo
DOI:10.1139/v82-360
日期:1982.10.1
Kinetic studies, secondaryα-deuterium kinetic isotopeeffects, primary chlorine kinetic isotopeeffects (1), Hammett ρ values determined by changing the substituent in the nucleophile, and activation parameters have been used to determine the detailed (relative) structures of the transition states for the SN2 reactions between para-substituted benzyl chlorides and thiophenoxide ion. A rationale for
Using Secondary α Deuterium Kinetic Isotope Effects To Determine the Symmetry of S<sub>N</sub>2 Transition States
作者:Kenneth Charles Westaway、Thuy Van Pham、Yao-ren Fang
DOI:10.1021/ja962088f
日期:1997.4.1
The secondary α deuterium and heavy atom kineticisotopeeffects found for two different SN2 reactions suggest that the magnitude of secondary α deuteriumkineticisotopeeffects can be determined by the length of only the shorter (stronger) reacting bond in an unsymmetrical SN2 transition state rather than by the usual nucleophile−leaving group distance. Although this means the interpretation of these