Metal-free Lewis acid mediated dehydrocoupling of phosphines and concurrent hydrogenation

The stoichiometric reaction of trityl cation with two equivalents of Ph2PH affords the phosphine stabilized phosphenium salt [Ph-2(H)PPPh2][B(C6F5)(4)] via hydride abstraction, while catalytic amounts of B(p-HC6F4)(3) effects catalytic phosphine dehydrocoupling with the liberation of H-2. This reaction is accelerated by the presence of olefin or imine, effecting concurrent hydrogenation.