37994-87-9Relevant academic research and scientific papers
Solvolysis-Decomposition of 1-Adamantyl Chloroformate: Evidence for Ion Pair Return in 1-Adamantyl Chloride Solvolysis
Kevill, Dennis N.,Kyong, Jin Burm,Weitl, Frederick L.
, p. 4304 - 4311 (1990)
In hydroxylic solvents, 1-adamantyl chloroformate reacts with loss of carbon dioxide and formation of both solvolysis and decomposition products.The rates of both processes are appreciably sensitive to solvent ionizing power, with the solvolysis slightly more so.The influence of anionic additives is discussed.For mixtures of hydroxylic solvents, the selectivities for the formation of solvolysis products are very similar to those observed in conventional solvolyses of 1-adamantyl derivatives.It is suggested that 1-Ad+Cl- ion pair intermediates are formed, and the observation of collapse requires that an identical collapse, corresponding to internal return, also occurs in 1-adamantyl chloride solvolysis.A comparison with solvolyses of other 1-AdOCOX compounds suggests that the initial ionization is not to 1-Ad+(OCOCl)- and that the 1-Ad+Cl- ion pair is formed either in a concerted process or via a very unstable (1-AdOCO)+Cl- ion pair.
Multiple Pathways in the Solvolysis of 1-Adamantyl Fluoroformate
Kevill, Dennis N.,Kyong, Jin Burm
, p. 258 - 265 (2007/10/02)
Reactions of 1-adamantyl fluoroformate in hydroxylic solvents have been studied.In solvents of high ionizing power and relatively low nucleophilicity, such as 2,2,2-trifluoroethanol-water mixtures, the reactions parallel those of 1-adamantyl chloroformate, and only solvolysis-decomposition reaction is observed.However, differing from the reactions of the corresponding chloroformate, in other solvents appreciable amounts pf attack at acyl carbon occur, more than 90percent in 80percent aqueous ethanol.Entropies of activation for attack at acyl carbon are considerably more negative than for solvolysis-decomposition.For the solvolysis-decomposition, a Grunwald-Winstein m value of 0.70 is observed.The kCl/kF ratios for solvolysis-decomposition are in the range of 104-105, suggesting appreciable C-X bond breaking in the transition state of the rate-determining step and arguing against rate-determining formation of a 1-Ad(1+)(OCOX)(1-) ion pair.Attack at acyl carbon is analyzed in terms of the two-term Grunwald-Winstein equation, and sensitivities toward changes in nucleophilicity and ionizing power are identical to those for solvolyses of n-octyl fluoroformate, which are believed to proceed via a tetrahedral intermediate.For each of the major pathways, selectivities toward the components of binary hydroxylic solvents are reported and discussed.
