Correlation of the rates of solvolysis of acetic p‐toluenesulfonic anhydride (acetyl p‐toluenesulfonate) and a comparison with acetyl halides†. (25th June 2013)

• Record Type: Journal Article
• Authors: Kevill, Dennis N.; Ryu, Zoon Ha; Page, Michael I.
• Is Part Of: Journal of physical organic chemistry. Volume 26:Number 12(2013:Dec.)
• Page Start: 983
• Page End: 988
• Publication Date: 2013-06-25
• Subjects: Chemistry, Physical organic -- Periodicals; 547.1
• DOI: 10.1002/poc.3146
• Languages: English
• ISSNs: 0894-3230

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The specific rates of <named-content id="d36e570" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">solvolysis</named-content> of acetyl <italic>p</italic>‐toluenesulfonate have been measured by a rapid‐response conductivity technique at temperatures in the temperature range of −10 to −55 °C. For 13 solvents at −39.6 °C, an extended Grunwald–Winstein equation correlation led to sensitivities to changes in solvent nucleophilicity of 0.56 and to changes in solvent ionizing power of 0.61. In 89.1% acetone at −20 °C, the comparison with acetyl bromide <named-content id="d36e579" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">solvolysis</named-content> led to a <italic>k</italic><sub>OTs</sub>/<italic>k</italic><sub>Br</sub> ratio of 1.4. In methanol and methanol‐<italic>d</italic> at −39.6 °C, the solvent deuterium isotope effect <italic>k</italic><sub>MeOH</sub>/<italic>k</italic><sub>MeOD</sub> is 0.99. These results are consistent with an S<sub>N</sub>l reaction with appreciable <named-content id="d36e610" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">nucleophilic</named-content> solvation or an S<sub>N</sub>2 reaction with a loose transition state. These two approaches lead to similar structures for the transition state. A solution of the acetyl <italic>p</italic>‐toluenesulfonate was conveniently prepared by the rapid reaction of <named-content id="d36e622" content-type="chemicalTechnology" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">acetyl chloride</named-content> with silver <italic>p</italic>‐toluenesulfonate in acetonitrile. Copyright © 2013 John Wiley & Sons, Ltd.</p> </abstract>