A Sulfoxide Reagent for One‐Pot, Three‐Component Syntheses of Sulfoxides and Sulfinamides

Sulfoxides and sulfinamides represent versatile sulfur functional groups found in ligands, chiral auxiliaries, and bioactive molecules. Canonical two‐component syntheses, however, rely on substrates with a preinstalled C−S bond and impede efficient and modular access to these sulfur motifs. Herein is presented the application of an easily prepared, bench‐stable sulfoxide reagent for one‐pot, three‐component syntheses of sulfoxides and sulfinamides. The sulfoxide reagent donates the SO unit upon the reaction with a Grignard reagent (RMgX) as a sulfenate anion (RSO(−)). While subsequent trapping reactions of this key intermediate with carbon electrophiles provide sulfoxides, a range of tertiary, secondary, and primary sulfinamides can be prepared by substitution reactions with electrophilic amines. The syntheses of sulfinamide analogs of amide‐ and sulfonamide‐containing drugs illustrate the utility of the method for the rapid preparation of medicinally relevant molecules.