Effect of sulfonyl protecting groups on the neighboring group participation ability of sulfonamide nitrogen

The addition of elemental bromide dissolved in C[H.sub.2][Cl.sub.2] to para-disubstituted benzodiaocines, where X is the same (H, C[H.sub.3], Br, OMe, N[O.sub.2]) or a different substituent as X and Y (C[H.sub.3], Br; OMe, N[O.sub.2]) has proceeded with competition between two pathways. The regio- and stereoselectivities have established the capability of sulfonamide nitrogen centers to engage in neighboring group participation.