Imino‐λ3‐iodane and Catalytic Amount of I2‐Mediated Synthesis of N‐Allylsulfenamides via [2,3]‐Sigmatropic Rearrangement

A facile metal-free [2,3]-sigmatropic rearrangement reaction of allyl sulfides viaN-sulfilimine intermediates has been developed. Treatment of allyl sulfides with imino-lambda(3)-iodanes in the presence of a catalytic amount of elemental iodine allowed the reaction to proceed under mild conditions and gave the correspondingN-allylsulfenamide compounds in moderate to good yields. SeveralN-allylsulfenamide structures have been confirmed by single-crystal X-ray crystallography. The reaction initially involves the sulfonylimino group transfer reaction between imino-lambda(3)-iodane and the sulfur atom, resulting in the formation ofN-sulfilimine species, followed by [2,3]-sigmatropic rearrangement to form theN-allylsulfenamide.