| Abstract
| - The solvolysis of 3-(trifluoromethyl)-3-indenyl tosylate(15) occurs with extensive isomerization to1-(trifluoromethyl)-3-indenyl tosylate (16), which reacts ina slower process to give the substitutionproduct 17. Kinetic analysis of a model involving anintermediate allyl cation/tosylate ion pair 18gave a partitioning ratio in CD3CO2D at99.6 °C for 18 of 7.7 for return with allylicrearrangementcompared with solvent capture. Studies of 15 withspecific 18O labeling show no scrambling inrecovered 15 and partial scrambling in rearrangement to16. The m value measuring thedependence of the reactivity of 15 on the solvent-ionizingparameter YOTs is 0.78, which issignificantly less than that of 1.23 for the analogous9-(trifluoromethyl)-9-fluorenyl tosylate 7.Normal salt effects in CF3CO2Hpredominate for 15, and the special salt effect involves nomorethan 14% capture of solvent-separated ion pairs by 0.551 MKO2CCF3. The substrate 15has a netdiminution in reactivity of more than 109 relative to thesecondary indanyl tosylate 22, with factorsof 106 and 103 attributable to antiaromaticityand to the electron-withdrawing CF3 group,respectively. The solvolysis of 15 is proposed to occurby formation of an ion pair with significantnucleophilic solvation at the relatively unhindered allylic carbon, butinternal return occurs inpreference to solvent or salt capture. Solvolysis of therearranged tosylate 16 occurs with a strongrate retardation by the γ-CF3 group, a large extent ofinternal return, and with a normal salt effect.
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