phosphorus ylide

chemical compound

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July 23, 2026

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A phosphorus ylide is a type of organic phosphorus compound discovered by Georg Wittig. These compounds are crucial intermediates in the Wittig reaction, a valuable method for synthesizing complex organic molecules like vitamins and steroids.1

Phosphorus ylides are distinct from phosphides, which are inorganic compounds formed between phosphorus and a metal. Phosphides have varied properties and structures, with some exhibiting metallic characteristics. Another related compound is phosphorus oxychloride (also known as phosphoryl chloride), a fuming liquid used in making phosphoric esters. Phosphine (PH₃) is a toxic gas related to ammonia, and its organic derivatives are called phosphines.2345

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organosulfur compound
Sulfonium and oxosulfonium salts; sulfur ylides
…sulfur ylides, by analogy with phosphorus ylides employed in the Wittig reaction. The structures of sulfonium ylides and oxosulfonium ylides are analogous to those of sulfoxides and sulfones, respectively. Stabilization of the negative charge on carbon is primarily due to the high polarizability of sulfur. While phosphorus ylides react with…
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…sulfur ylides, by analogy with phosphorus ylides employed in the Wittig reaction. The structures of sulfonium ylides and oxosulfonium ylides are analogous to those of sulfoxides and sulfones, respectively. Stabilization of the negative charge on carbon is primarily due to the high polarizability of sulfur. While phosphorus ylides react with…
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