1707-09-1Relevant academic research and scientific papers
Hydrophosphonylation of Alkynes with Trialkyl Phosphites Catalyzed by Nickel
Islas, Rosa E.,García, Juventino J.
, p. 4125 - 4131 (2017)
The use of simple and inexpensive NiCl2?6 H2O 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)2P(O)H as the species that undergo the addition into the C≡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.
Diastereoselective synthesis of 2-amino-4-phosphonobutanoic acids by conjugate addition of lithiated schoellkopf's bislactim ethers to vinylphosphonates
Ruiz, Maria,Fernandez, M. Carmen,Diaz, Aniana,Quintela, Jose M.,Ojea, Vicente
, p. 7634 - 7645 (2007/10/03)
Conjugate additions of lithiated bislactim ethers derived from cyclo-[Gly-Val] and cyclo-[Ala-Val] to α, β, or α,β -substituted vinylphosphonates allow direct and stereoselective access to a variety of 3- or 4-monosubstituted and 2,3-, 2,4-, or 3,4-disubstituted 2-amino-4-phosphonobutanoic acids (AP4 derivatives) in enantiomerically pure form. The relative stereochemistry was assigned by X-ray diffraction analysis or NMR study of 1,2-oxaphosphorinane derivatives. Competitive eight-membered "compact" and "relaxed" transition-state structures are invoked to rationalize the stereochemical outcome of the conjugate additions.
