CaltechAUTHORS
  A Caltech Library Service

Kinetics and Equilibrium Constants for Reactions of α-Phenyl-Substituted Cyclopropylcarbinyl Radicals

Halgren, Thomas A. and Roberts, John D. and Horner, John H. and Martinez, Felix N. and Tronche, Christopher and Newcomb, Martin (2000) Kinetics and Equilibrium Constants for Reactions of α-Phenyl-Substituted Cyclopropylcarbinyl Radicals. Journal of the American Chemical Society, 122 (13). pp. 2988-2994. ISSN 0002-7863. http://resolver.caltech.edu/CaltechAUTHORS:20151001-101404659

[img] PDF - Supplemental Material
See Usage Policy.

1779Kb
[img] PDF - Supplemental Material
See Usage Policy.

433Kb

Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20151001-101404659

Abstract

Laser-flash photolysis methods were used to determine Arrhenius functions for cyclizations of the 4,4-diphenyl-3-butenyl (2) and trans-4-phenyl-3-butenyl (5) radicals to the 1,1-diphenylcyclopropylcarbinyl (1) and 1-phenylcyclopropylcarbinyl (4) radicals, respectively. At 20 °C, the cyclization rate constants are 1.7 × 10^7 and 5.4 × 10^6 s^(-1). Equilibrium constants for the two processes were estimated and evaluated with thermochemical data and via computational methods, and Arrhenius functions for the ring-opening reactions of the cyclopropylcarbinyl radicals were calculated. The cyclization reactions of 2 and 5 are strongly enthalpy controlled. Production of radicals 1 and 2 from the corresponding tert-butylperoxy esters in the presence of Et_3SnH gave diphenylcyclopropylmethane and 1,1-diphenyl-1-butene from H-atom trapping of radicals 1 and 2 and 4-phenyl-1,2-dihydronaphthalene which derives from the product radical formed by addition of the radical moiety in 2 to the cis-phenyl group. Rate constants for the latter cyclization of 2 and for reactions of radicals 1 and 2 with Et_3SnH were obtained from the indirect kinetic studies.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1021/ja991114hDOIArticle
http://pubs.acs.org/doi/abs/10.1021/ja991114hPublisherArticle
http://pubs.acs.org/doi/suppl/10.1021/ja991114hRelated ItemSupporting Information
Additional Information:© 2000 American Chemical Society. Received April 8, 1999. Revised Manuscript Received February 2, 2000. Publication Date (Web): March 21, 2000. We are grateful to the National Science Foundation for financial support (CHE-9614968 to M.N. and GP-8540 to J.D.R.).
Funders:
Funding AgencyGrant Number
NSFCHE-9614968
NSFGP-8540
Record Number:CaltechAUTHORS:20151001-101404659
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:20151001-101404659
Official Citation:Kinetics and Equilibrium Constants for Reactions of α-Phenyl-Substituted Cyclopropylcarbinyl Radicals Thomas A. Halgren, John D. Roberts, John H. Horner, Felix N. Martinez, Christopher Tronche, and Martin Newcomb Journal of the American Chemical Society 2000 122 (13), 2988-2994 DOI: 10.1021/ja991114h
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:60659
Collection:CaltechAUTHORS
Deposited By: Ruth Sustaita
Deposited On:02 Oct 2015 16:07
Last Modified:02 Oct 2015 16:07

Repository Staff Only: item control page