The generation and reactions of sulfenate anions. An update

Sulfenate anions (RSO-) represent the conjugate base of sulfenic acids (RSOH) and are known predominately for their S-nucleophilicity. In the early stages of sulfenate research this often meant the formation of a benzyl or methyl sulfoxide, often to confirm the intermediacy of a sulfenate. Many recent contributions have demonstrated the diversity of functionalization of sulfenates, and those new investigations form the basis of this review. This synopsis begins by describing the predominant methods to generate sulfenates and aspects of their structure. The sections addressing sulfenate reaction chemistry focus on stereoselective S-functionalization chemistry, transition metal catalyzed S–C bond formation (cross-coupling) and bond cleavage, and the discovery of particularly novel reactions and applications. This latter area includes a description of the organocatalytic roles played by sulfenates and some new metal-free sulfenate coupling chemistry. The literature is covered to early 2022.