Metal-free Trans-imination Using Iminoiodane

Abstract

Iminoiodanes are useful nitrene precursors and effective oxidants in the reactions with various organic substrates. Most of the known reactions of iminoiodanes are carried in the presence of transition metal catalysts, required for the in-situ generation of active metal-nitrenoid species. Recently, several groups have reported the aziridination of olefines, C-H amination of alkanes, and imination of aldehydes using iminoiodanes under metal-free conditions. However, the imination of sulfides using iminoiodanes under metal-free condition is still unknown. Herein, we report the new reaction of metal free trans-imination reaction of sulfides using iminoiodanes in the presence of catalytic amounts of elemental iodine. The trans-imination reactions of various alkyl or aryl sulfides proceed at room temperature to give the corresponding sulfilimines in low to good yields. The reaction of allyl sulfides under similar conditions proceeds as [2,3]-sigmatropic rearrangement to give the corresponding allyl sulfonamides in good yields. The same condition using triphenyl phosphine instead of sulfides produced iminophosphorane in good yield, and the product was confirmed by X-ray crystallography.