Rearrangements of nitrones to O-alkyl oximes via geometrically isomerizing iminoxy radicals

Kinetic and product study of the thermolyses of several nitrones and O-alkyloximes

“…But the O-benzhydryl derivatives have been shown to be completely configurationally stable under the above conditions. 4 Similarly, the (Z)-benzyl derivative, 10, was shown to be (5) configurationally stable. The remarkable configurational stability of benzophenone O-methyloxime derivatives has been previously reported.28 Thus, in contrast with 0-methyl, benzyl, and benzhydryl derivatives, the stability of the developing trityl radical appears to be responsible for lowering the activation energy and promoting the homolysis.…”

O−H Bond Dissociation Enthalpies of Oximes: A Theoretical Assessment and Experimental Implications

“…(2) What are the effects of various substitutions on the oxime O−H BDEs? This particular question has not been adequately studied previously, not only due to the lack of reliable experimental data but also because of the fact that the electronic structure of aryl- and alkyl-substituted iminoxyl radicals has been controversial for many years. ,,,,− …”

The E isomer of acetophenone iminoxy, an overlooked radical

“…Z/E isomerization in iminoxy radicals leading to an equilibrated mixture of two radicals with separate ESR signals has been observed frequently. 10 The same situation exists in a number of paraor meta-substituted acetophenone iminoxy radicals.11,12 It therefore seemed desirable to confirm the previous assignment of the ESR signal of the acetophenone iminoxy radical to exclusively (Z)-l with the aid of the compounds perdeuterated either in the methyl or phenyl group.…”