Amides of sulfonic acids $\ce{RS(=O)2NR'2}$, e.g. $\ce{PhS(=O)2NHCH3}$ N-methylbenzenesulfonamide.
Source: PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1369 [Terms] [Paper]