Magnesium-Catalyzed Tandem Dehydrogenation-Dehydrocoupling: An Atom Economical Access to Alkynylboranes.

Owing to the unusual reactivity of sterically hindered amine-borane complexes, a catalytic system based on magnesium salts was designed to perform a tandem dehydrogenation-dehydrocoupling between terminal alkynes and boranes. The reaction is providing pure alkynylboranes within few minutes at room temperature, with only two molecules of hydrogen as a byproduct.