Facile synthesis of diphosphoryl acetylenes through copper-catalyzed cross coupling

Organic molecules containing 1,2-diphosphonate moiety are of great value in organic synthesis. Diphosphoryl acetylenes (or named as ethyne-1,2-diyldiphosphonates) are a class of molecules utilized for synthesis of diverse phosphorus compounds applicable in multiple fields. However, present stoichiometric methods for the preparation of diphosphoryl acetylenes generally requires multiple steps or harsh conditions. Herein, we report a facile synthesis of diphosphoryl acetylenes, in which the readily available ethynyl phosphonates couple with dialkyl phosphonates through cheap copper catalysis. A series of diphosphoryl acetylenes in symmetric or unsymmetric fashions are facilely prepared. This protocol demonstrates advantages of mild reaction conditions, inert atmosphere-free, cheap catalyst, base-free, and high efficiency to serve as a practical method for synthesis of diphosphoryl acetylenes.