Alkenylthioimidoyl radicals: competition between beta-scission and cyclization to dihydrothiophen-2-ylidene-amines.
[reaction: see text] But-3-enylthioimidoyl radicals were shown by EPR spectroscopy and end product analysis to ring-close predominantly in the 5-exo mode with a rate constant of 2.4 x 10(4) s(-)(1) at 300 K to afford substituted dihydrothiophenylmethyl radicals. This ring closure was in competition with dissociation to but-3-enyl radicals and an isothiocyanate. The dissociation predominated at temperatures above ca. 300 K.
Minozzi
Matteo
M
School of Chemistry, University of St. Andrews, St. Andrews, Fife, KY16 9ST, UK.
Nanni
Daniele
D
Walton
John C
JC