Sulfoximines are of considerable interest for incorporation into medicinal compounds. A convenient synthesis of N-protected sulfoximines is achieved, under mild conditions, by rhodium-catalyzed transfer of carbamates to sulfoxides. The first examples of 4-membered thietane-oximines are prepared. Sulfoximines bearing Boc and Cbz groups are stable to further cross coupling reactions, and readily deprotected. This method may facilitate the preparation of NH-sulfoximines providing improved (global) deprotection strategies, which is illustrated in the synthesis of methionine sulfoxide (MSO).