Synthesis of 1,2-Diamine Derivatives Using a Rhodium Catalyst

Du Bois et al. have reported the 1,2-diamination reactions of alkenes using a rhodium catalyst. According to their results, aziridines 2 are formed from alkenes and a sulfamide 1 by the Rh₂(esp)₂ catalyst and iodobenzene diacetate-promoted aziridination. By adding sodium iodide, the aziridines 2 are cleaved to form the acyclic intermediate 3 and the consequent ring-closing process affords the 5-membered cyclic sulfamides 4. The given sulfamides 4 are hydrolyzed by an aqueous pyridine and converted to the mono Boc-protected 1,2-diamines. In this synthetic process, the tandem ring-opening and ring-closing reactions proceed involving two S_N2 type substitutions. Therefore, when E alkenes are used as starting materials, trans-1,2-diamines are given, and in the case of Z alkenes, cis-1,2-diamine derivatives are given, respectively.