Meta-substituent effects on benzyl free-radical stability

Journal Article · Thu Feb 01 23:00:00 EST 1990 · Journal of Organic Chemistry; (United States)

DOI:https://doi.org/10.1021/jo00290a041· OSTI ID:5977288

Fisher, T H; Dershem, S M; Prewitt, M L ^[1]

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1. Mississippi State Univ., Mississippi State (United States)

A series of 5-substituted 3-cyanotoluenes was synthesized, and the relative rates of N-bromosuccinimide bromination were determined in benzene at 80C. The resulting {sigma}{sub F}{sup {sm bullet}} values of meta Me, H, Br, NO{sub 2}, and CN were found to be 0.03, 0.00, {minus}0.03, {minus}0.04, and {minus}0.10, respectively. Of these meta substitutents, all but methyl were found to be destabilizing to the intermediate benzyl free radical. These meta substituent results are consistent were reported {sigma}{sub {alpha}}{sup {sm bullet}} and {alpha}{sub c}{sup {sm bullet}} values and cast doubt upon reports that assume meta substituents have no influence on free-radical stability.

• OSTI ID: 5977288
• Journal Information: Journal of Organic Chemistry; (United States), Journal Name: Journal of Organic Chemistry; (United States) Vol. 55:3; ISSN 0022-3263; ISSN JOCEA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKYLATED AROMATICS
AROMATICS
ARYL RADICALS
BENZYL RADICALS
CHEMICAL PREPARATION
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADICALS
STABILIZATION
SYNTHESIS