A study was carried out on the solvolysis of 1-adamantyl chlorothioformate (1-AdSCOCl,
1) in hydroxylic solvents. The rate constants of the solvolysis of
1 were well correlated using the Grunwald–Winstein equation in all of the 20 solvents (R = 0.985). The solvolyses
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A study was carried out on the solvolysis of 1-adamantyl chlorothioformate (1-AdSCOCl,
1) in hydroxylic solvents. The rate constants of the solvolysis of
1 were well correlated using the Grunwald–Winstein equation in all of the 20 solvents (R = 0.985). The solvolyses of
1 were analyzed as the following two competing reactions: the solvolysis ionization pathway through the intermediate (1-AdSCO)
+ (carboxylium ion) stabilized by the loss of chloride ions due to nucleophilic solvation and the solvolysis–decomposition pathway through the intermediate 1-Ad
+Cl
− ion pairs (carbocation) with the loss of carbonyl sulfide. In addition, the rate constants (
kexp) for the solvolysis of
1 were separated into
k1-Ad+Cl− and
k1-AdSCO+Cl− through a product study and applied to the Grunwald–Winstein equation to obtain the sensitivity (
m-value) to change in solvent ionizing power. For binary hydroxylic solvents, the selectivities (
S) for the formation of solvolysis products were very similar to those of the 1-adamantyl derivatives discussed previously. The kinetic solvent isotope effects (KSIEs), salt effects and activation parameters for the solvolyses of
1 were also determined. These observations are compared with those previously reported for the solvolyses of 1-adamantyl chloroformate (1-AdOCOCl,
2). The reasons for change in reaction channels are discussed in terms of the gas-phase stabilities of acylium ions calculated using Gaussian 03.
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