Regioselective N-arylation of N-Acylsulfenamides Enabled by o-Quinone Diimides.

The functionalization of N-acylsulfenamides is a research focus in organosulfur chemistry, as the N-S array has unique properties and versatile applications. Although great progress has been made in S-functionalization, the N-functionalization, especially the N-arylation of N-acylsulfenamides, has rarely been explored because of the lower nucleophilicity of the N-site. Herein, we report a Brønsted acid-catalyzed regioselective N-arylation reaction of N-acylsulfenamides with o-quinone diimides. Under mild and metal-free conditions, a wide range of N-arylated N-acylsulfenamides have been prepared in good yields with excellent regioselectivity. The ease of gram-scale synthesis and transformations into useful sulfonamides demonstrates their synthetic practicality.