27852-78-4Relevant articles and documents
Solvent Effects on Solvolytic Reactivity. A Diagnostic Test for Neighboring-Group Assistance by ? Conjugation in Solvolysis Reactions
Roberts, Donald D.
, p. 2521 - 2526 (2007/10/02)
The solvolysis rates of 13 arenesulfonates have been determined in mixtures of ethanol and water (the E-series solvents) and acetic acid and formic acid (the A-series solvents).The substrates studied include the following: neophyl (1), 2-adamantyl (2), neopentyl (3), and cyclooctyl (4) tosylates; cyclopropylcarbinyl pemsylate (5a) and tosylate (5b); exo-2-norbornyl tosylate (6); cyclobutylcarbinyl (7), cyclobutyl (8), and pinacolyl (9) brosylates; cyclopentyl (10), cyclohexyl (11), and 2-propyl (12) tosylates; and cyclopentylcarbinyl brosylate (13).Correlations of the rate data by eq 1 t(Y) = a + b log kt(neophyl-OTs)> showed that the various substrates responded differently to the examined solvent effects on the solvolytic reactivity.For compounds 2-4, linear correlations were obtained.For compounds 5-9, E-line, A-line dispersions were noted which diverged with increasing ionizing power; for compounds 10-12, parallel E-line, A-line dispersions were obtained; and for compound 13, an E-line, A-line dispersion was observed which converged with increasing ionizing power.Stastistical analyses of the rate data correlations confirmed the significance of the E or A classification of data.The results are interpreted in terms of differences in the involvement of solvent in the transition state for those solvolyses assisted by bridging from those assisted by C-C ? bond hyperconjugation.
