Synthesis of Tetrazole and Oxadiazole Sulfoximines

Significance

Reported are reasonably efficient syntheses of tetrazole and oxadiazole sulfoximines. The N-cyano sulfoximines 1, which can be prepared from readily available sulfides and cyanamide in two steps or by direct cyanation of the NH-sulfoximines, undergo a [2+3] cycloaddition reaction with NaN₃ to afford tetrazole sulfoximines 2, which upon treatment with TFAA rearrange into 5-substituted oxadiazole sulfoximines 3. The reaction sequence starting from a chiral NH-sulfoximine proceeds without loss of enantiopurity.