Hydrophosphonylation of Alkynes with Trialkyl Phosphites Catalyzed by Nickel

摘要

The use of simple and inexpensive NiCl2 center dot 6H(2)O as a catalyst precursor for C P bond formation in the presence of commercially available trialkyl phosphites (P(OR)(3), R=Et, iPr, Bu, SiMe3) along with several alkynes is presented. Control experiments showed the in situ formation of (RO)(2)P(O)H as the species that undergo the addition into the C equivalent to C bond at the alkynes to yield the product of P-H addition. The hydrophosphonylation of diphenylacetylene with P(OEt)(3), P(OiPr)(3), and P(OSiMe3)(3) proceeds in high yields (> 92%) without the need of a specific solvent or ligand. This method is useful for the preparation of organophosphonates for both phenylacetylene as a terminal alkyne model and internal alkynes in yields that range from good to modest.