Acyl vs Sulfonyl Transfer in N-Acyl β-Sultams and 3-Oxo-β-sultams

(Matrix presented) N-Acylsulfonamides usually react with nucleophiles by acyl transfer and C-N bond fission. However, the hydrolysis of N-acyl β-sultams is a sulfonyl transfer reaction that occurs with S-N fission and opening of the four-membered ring. Similar to other β-sultams, the N-acyl derivatives are at least 10⁶-fold more reactive than N-acyl sulfonamides. 3-Oxo-β-sultams are both β-lactams and β-sultams but also hydrolyze with preferential S-N bond fission.