Azo synthesis meets molecular iodine catalysis
Abstract
A metal-free synthetic protocol for azo compound formation by the direct oxidation of hydrazine HN–NH
bonds to azo group functionality catalyzed by molecular iodine is disclosed. The strengths of this reactivity
include rapid reaction times, low catalyst loadings, use of ambient dioxygen as a stoichiometric oxidant, and
ease of experimental set-up and azo product isolation. Mechanistic studies and density functional theory
computations offering insight into this reactivity, as well as the events leading to azo group formation are
presented. Collectively, this study expands the potential of main-group element iodine as an inexpensive
catalyst, while delivering a useful transformation for forming azo compounds.