Palladium-Catalyzed Double Phosphorylation of Alkynes

Significance

In previous work, the authors have reported the nickel-catalyzed addition of hydrogen phosphonates to alkynes (J. Am. Chem. Soc. 2004, 126, 5080). In the present study an unprecedented dehydrogenative cis double phosphorylation reaction catalyzed by a divalent palladium(II) complex is disclosed. Importantly, use of the reactive cyclic H-phosphonate 1 as well as addition of methyl acrylate to serve as a hydrogen scavenger was necessary to obtain a diverse range of cis-phosphorylated alkenes in good yields. Interestingly, implementation of zerovalent palladium(0) complexes predominatly gave monophosphorylated alkene products.