Dimerizations of nitrile oxides to furoxans are stepwise via dinitrosoalkene diradicals: a density functional theory study.
Density functional theory calculations at the B3LYP/6-31G* level on the dimerization reactions of acetonitrile oxide and para-chlorobenzonitrile oxide to form furoxans indicate that these processes are stepwise involving dinitrosoalkene intermediates that have considerable diradical character. The rate-determining steps for these two reactions correspond to C-C bond formation. The retardation of dimerization in aromatic nitrile oxides arises from the interruption of conjugation between the nitrile oxide and aryl groups in the C-C bond formation step. The present study also suggests that the isomerization of single-ring furoxans occurs via a diradical intermediate mechanism.
Yu
Zhi-Xiang
ZX
Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA.
Caramella
Pierluigi
P
Houk
K N
KN