Brønsted Base Mediated Stereoselective Diphosphination of Terminal Alkynes with Diphosphanes

A Brønsted base
mediated stereoselective diphosphination of
terminal alkynes with diphosphanes proceeds to deliver the corresponding
(E)-1,2-diphosphino­ethenes in good yields.
The reaction of aromatic alkynes occurs efficiently in the presence
of a catalytic amount of LiO-t-Bu while MN­(TMS)2 (M = Li or Na) gave better results in the case of aliphatic
substrates. The Brønsted base mediated protocol can offer a good
alternative to precedented transition-metal-catalyzed or radical-promoted
approaches to the 1,2-diphosphino­ethene framework of potent
interest in catalysis and coordination chemistry.