A stable solid model for protein sulfenyl iodides.

The first simple sulfenyl iodide that is a pure stable crystalline solid is reported. This product, ISCMe(2)CH(NHCbz)CONH-Ph-p-Cl(10), contains linkages that simulate the two peptide linkages vicinal to the -SI moiety in a protein sulfenyl iodide. Unlike typical simple sulfenyl iodides, solid 10 remains unchanged at ambient conditions for more than ten weeks; however, it is quite reactive in solution. Under proper circumstances, therefore, a sulfenyl iodide is proved to be a stable but highly reactive species. The model 10 and related compounds should afford prospects for better understanding of the unusual stabilities of certain protein sulfenyl iodides and of ways in which other such compounds may function in mediating iodination reactions in the thyroid gland.