Recent trends and applications of the Cadiot-Chodkiewicz reaction.

The Cadiot-Chodkiewicz reaction offers an elegant strategy for the formation of 1,3-diynes via Cu-catalyzed cross-coupling of alkynyl halides with terminal alkynes in the presence of an amine. Since both unsymmetrical and symmetrical diacetylenes are of considerable interest due to their pharmaceutical, biological and synthetic applications, novel developments in the field of the Cadiot-Chodkiewicz reaction are of great importance. C(sp)-C(sp) coupling plays a central role in the total synthesis of many natural products and polyynes. This review is devoted to the new protocols and applications of the Cadiot-Chodkiewicz cross-coupling reaction that have been developed recently (2015-2019).