Dimerizations of nitrile oxides to furoxans are stepwise via dinitrosoalkene diradicals: a density functional theory study

Zhi-Xiang Yu; Pierluigi Caramella; K N Houk

doi:10.1021/ja037325a

Dimerizations of nitrile oxides to furoxans are stepwise via dinitrosoalkene diradicals: a density functional theory study

J Am Chem Soc. 2003 Dec 17;125(50):15420-5. doi: 10.1021/ja037325a.

Authors

Zhi-Xiang Yu¹, Pierluigi Caramella, K N Houk

Affiliation

¹ Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095-1569, USA.

PMID: 14664587
DOI: 10.1021/ja037325a

Abstract

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.