167114-16-1Relevant articles and documents
Alkynylcopper(I) complexes with PPh3 ligands. Preparation, structure, and alkynyl ligand transfer to palladium(II) complexes
Osakada, Kohtaro,Takizawa, Tadashi,Yamamoto, Takakazu
, p. 3531 - 3538 (2008/10/09)
Reactions of copper alkoxide complexes Cu(OCH(CF3)2)(PPh3)3, Cu(OCHPh2)(PPH3)3, and [Cu(OPh)(PPh3)2]2 with HC≡CCOOR (R = Me, Et, tBu) give alkynyl copper complexes formulated as Cu2(C≡CCOOR)2(PPh3)3 (1, R = Me; 2, R = Et; 3, R = tBu). The 1H, 13C{1H}, and 31P{1H} NMR spectra agree with the structures containing two bridging alkynyl ligands that are coordinated to Cu(PPh3) and to Cu(PPh3)2 units. The copper alkoxide complexes react with alkynes HC≡CSiMe3, HC≡CPh, and HC≡CC6H4-p-Me to give alkynylcopper(I) complexes [Cu(C=CR′)(PPh3)]4 (4, R′ = SiMe3; 5, R′ = Ph; 6, R′ = C6H4-p-Me). X-ray crystallography of 4·Et2O reveals a molecular structure containing a cubane-like core composed of four copper(I) centers bridged by four alkynyl ligands, each of which is coordinated to three Cu centers as a μ3-η1:η1:η1-ligand. Complex 5 undergoes ligand substitution by HC≡CCOOEt in the presence of PPh3 to give 2. Complexes 1-6 react with PdCl2(PEt3)2 to cause alkynyl ligand transfer from Cu to Pd. Reactions of 1-3 with 0.5 equiv of PdCl2(PEt3)2 in the presence of PPh3 give trans-Pd(C≡CCOOR)2(PEt3)2 accompanied by formation of CuCl(PPh3)3. Complex 4 undergoes alkynyl ligand transfer to give trans-PdCl(C≡CSiMe3)(PEt3)2 exclusively, while similar reactions of 5 and 6 give mixtures of trans-Pd(C≡CAr)2(PEt3)2 and trans-PdCl(C≡CAr)(PEt3)2 (Ar = Ph, C6H4-p-Me).
