CadiotChodkiewicz

The Cadiot-Chodkiewicz coupling is a chemical reaction used to form a new carbon-carbon bond between a terminal alkyne and a haloalkyne. This reaction is a variation of the Glaser coupling and allows for the synthesis of unsymmetrical diynes. The reaction typically involves the use of a copper(I) catalyst, often in the presence of a base such as an amine.

The general mechanism involves the deprotonation of the terminal alkyne by the base, forming a copper(I) acetylide. This acetylide then undergoes oxidative coupling with the haloalkyne. The specific mechanism can vary depending on the exact reaction conditions and catalysts used, but it generally proceeds through a series of copper-mediated steps.

This reaction is particularly useful in organic synthesis when it is desired to couple two different alkyne units together to create more complex molecular structures. It has found applications in the synthesis of natural products, pharmaceuticals, and materials science. The Cadiot-Chodkiewicz coupling offers a regioselective method for forming unsymmetrical diynes, which can be challenging to achieve through other synthetic routes. The reaction conditions are generally mild, making it compatible with a variety of functional groups.