Sulfonium ylides are a type of chemical compound characterized by a positively charged sulfur atom bonded to a negatively charged carbon atom. These compounds are often used in organic chemistry for various reactions, including Wittig reactions, where they help form double bonds in organic molecules. The general structure of sulfonium ylides includes a sulfonium ion, which is a sulfur atom surrounded by three organic groups, and a ylide, which is a neutral molecule with a positive and a negative charge. Their unique properties make them valuable intermediates in synthesizing complex organic compounds.