Castro-Stephens coupling

The Castro-Stephens Coupling is a cross coupling reaction between a Copper(I) acetylide and an aryl halide forming a disubstituted alkyne and a copper(I) halide.


 * [[Image:Castro-Stephens reaction.png|600px|Castro-Stephens reaction]]

The reaction was discovered in 1963 by chemists Casto and Stephens and is used as a tool in the organic synthesis of organic compounds. The reaction has similarities with the much older Rosenmund-von Braun synthesis (1916) between aryl halides and copper(I) cyanide and was itself modified in 1973 with as the Sonogashira coupling by adding a palladium catalyst and preparing the organocopper compound in situ.

A typical reaction is the coupling of iodobenzene with the copper acetylide of phenylacetylene in refluxing pyridine to diphenylacetylene:
 * [[Image:Castro-Stephens application.png|600px|Application of Catsro-Stephens coupling with phenyliodine]]