Polar Effects. X. Polar Substituent Effects in the Solvolysis of 3-Substituted 1-Adamantyl Bromides and Tiluenesulfonates

Article abstract of DOI:10.1002/hlca.19820650606

The rate constants for 3-substituted adamantyl p-toluenesulfonated 3a-3k in ethanol/water 80:20 correlate well with the respective inductive subsitutent constants ?^q_I.The reaction constant ρ for the toluenesulfonates 3 is 10percent karger than for the corresponding bromides 2, indicating somewhat more charge separation in the activation of the toluenesulfonates.Evidence is presented that stabilization of the resultant 1-adamantyl cations by induction involves graded 1,3-bridging, which is favored when the subsituent is an electrofugal group, and that stabilization by n-electron donors involves C,C-hyperconjugation.Rate ratios for the toluenesulfonates 3 and the bromides 1 exceed 1E3 and are almost independent of the 3-subsituents.The implications of this are discussed in the light current hypotheses.