An AM1 Study of the Coupling Reaction of Radicals with Acetone Enolate Ions and some Related Nucleophiles

PIERINI, A. B.; BOROSKY, G.L.; BAUMGARTNER, M. T

JOHN WILEY & SONS INC

Año: 1992 vol. 44 p. 759 - 759

e here report an am1 study for the reaction of different types of radicals with the acetone enolate ion 1 and other ambident nucleophiles. The theoretical reactivity order determined is phenyl > methyl > tert-butyl ≅ bicyclo-[2.2.1]hept-1-yl. The activation energy for the coupling of aliphatic radicals is ascribed mainly to nonbonded interactions. Considering possible solvent effects, we propose the same order of reactivity in solution. The coupling reaction of phenyl radical with 1 is an exothermic process with nonactivation energy in the gas phase. Any energy barrier in solution is here ascribed to desolvation of the anion. The regiochemistry of the coupling of radicals with ambident nucleophiles such as 1, phenoxide, or phenylamide anions is also explained on a theoretical basis.