Sulfonium compounds are a class of chemical compounds that contain a positively charged sulfur atom bonded to three organic groups. They are often represented by the general formula R₃S⁺, where R represents the organic groups. These compounds are known for their role in various chemical reactions, including as intermediates in organic synthesis and as reagents in the formation of other compounds. One common example of a sulfonium compound is trimethylsulfonium chloride, which is used in organic chemistry for methylation reactions. Sulfonium compounds can also participate in nucleophilic substitution reactions, making them valuable in the development of pharmaceuticals and other chemical products.