Stepwise Versus Concerted Mechanisms at Trigonal Carbon - Transfer Of The 1,3,5-Triazinyl Group Between Aryl Oxide Ions In Aqueous-Solution

Hunter, A. and Renfrew, M. and Rettura, M. and Taylor, J.A and Whitmore, J.M.J and Williams, A. (1995) Stepwise Versus Concerted Mechanisms at Trigonal Carbon - Transfer Of The 1,3,5-Triazinyl Group Between Aryl Oxide Ions In Aqueous-Solution. Journal of the American Chemical Society, 117 (20). pp. 5484-5491. ISSN 0002-7863. (The full text of this publication is not available from this repository)

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Official URL
http://dx.doi.org/10.1021/ja00125a008

Abstract

Displacements of 4-nitrophenolate ions from 2-(4-nitrophenoxy)-4,6-dimethoxy-1,3,5-triazine by substituted phenolate ions in aqueous solution obey a linear Bronsted-type equation, log k(Aro) = 0.951pK(a) - 10.98, over a range of pK(a) values greater than and less than the pK(a) of the leaving phenol. The absence of curvature is consistent with a mechanism involving a single transition state. This conclusion is supported by the existence of cross-correlation effects (p(xy) = 0.0561) on beta(nuc) of the pK(a) of the leaving group and on beta(1g) of the pK(a) of the nucleophile on beta(1g). The value of beta(eq), the Bronsted selectivity for transfer of the triazinyl function between phenolate ions, is calculated from the Bronsted data to be 1.48. The identity reaction of 3,4-dinitrophenolate ion with the (3,3-dinitrophenoxy)triazine is calculated to have a Kreevoy-Albery tau value of 1.04, indicating that in this case changes in effective charge on entering and leaving ligands are approximately balanced.

Item Type: Article
Uncontrolled keywords: Nucleophilic Vinylic Substitution; Single Transition-State; Acyl Group Transfer; 50-Percent Me2so-50-Percent Water; Nonperfect Synchronization; Stereoelectronic Factors; Intermediate; Kinetics; Regioselectivity; Reactivity
Subjects: Q Science > QD Chemistry
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences
Depositing User: P. Ogbuji
Date Deposited: 05 Oct 2009 07:57
Last Modified: 05 Oct 2009 07:57
Resource URI: http://kar.kent.ac.uk/id/eprint/19611 (The current URI for this page, for reference purposes)
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