Phosphine-gold(I) derivatives of 1,1′-bis(alkynyl)metallocenes: Molecular structures of Fc’(CCX)2 [X = Au(PPh3), SiMe3] and Au4{(CC)2Fc’}2(PPh3)2 [Fc’ = Fe(η-C5H4-)2]

Air‐Stable, Dinuclear and Tetranuclear σ,π‐Acetylide Gold(I) Complexes and Their Catalytic Implications

“…The possibility that s,p-digold alkynide complexes play a key role as active species in the cycloadddition of alkynes [1][2][3][4][5][6][7][8][9] has recently been put forward. [10] Although precedents for the formation of digold-acetylide complexes [11][12][13][14][15][16][17] and gemdiaurated species [18][19][20] can be found in the literature, we were among the first to isolate fluxional complexes with two Au I atoms of bulky biphenylphosphines connected to the C C triple bond of phenylacetylene through the s and p bonds, [21] supporting their involvement in the catalytic intermolecular [2+2] alkyne-alkene cycloaddition reaction (Scheme 1). [21] Simultaneously, Widenhoefer and co-workers succeeded in isolating dinuclear gold(I) s,parylacetylide complexes with bulky, 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene as the co-ligand (Scheme 1).…”

“…When intermediate complex 15 was submitted to hydrolysis, it decomposed to amine-Au I complex 14 and the corresponding ketone (see Scheme 4). Although this intermediate (15) could not be characterized by single-crystal XRD, its presence with very high purity upon addition of 2, 11, and 12 was supported by MALDI-TOF-MS and 31 P, 13 C, and 1 H NMR spectroscopy. Furthermore, 31 P, 13 C, and 1 H NMR spectroscopic data for 15 agree with the peaks observed under the reaction conditions of 11 and 12 promoted by 2.…”

Isolable Tris(alkyne) and Bis(alkyne) Complexes of Gold(I)

“…[9][10][11] Our efforts in this area led to the isolation of gold(I) (mono)alkyne compounds such as [Au(EtCCEt)Cl] and [(N{(C 3 F 7 )C-(Dipp)N} 2 )Au(EtC CEt)]. [18][19][20][21][22][23][24] Wittig and Fischer reported a gold p alkyne complex [Au(coct) 2 Br] in 1972 (coct = cyclooctyne) featuring two alkyne units on a gold center, but structural data are not available. [14][15][16][17] In contrast, molecules with more than one p-bonded alkyne moiety on gold are extremely rare.…”

“…[9] A limited number of structurally characterized gold complexes with more than one alkynyl metal moiety, also commonly referred to as s acetylides, are known, but they represent a different category. [18][19][20][21][22][23][24] Wittig and Fischer reported a gold p alkyne complex [Au(coct) 2 Br] in 1972 (coct = cyclooctyne) featuring two alkyne units on a gold center, but structural data are not available. [25] Hüttel and Forkl also reported some gold adducts possibly involving more than one simple alkyne unit on gold, but the compounds were thermally unstable and poorly characterized.…”

Alkynyl Coinage Metal Clusters and Complexes–Syntheses, Structures, and Strategies

“…However in the presence of CuI, formationo fatetranuclear gold(I) complex [Au 4 {(C C) 2 Fc} 2 (PPh 3 ) 2 ]( 49)i so bserved. [112] Theg old(I)a toms (Au 4 )a re arranged in ar homboidal fashion andA u···Au distances account for typical aurophilic interactions (3.0029(6) to 3.2956 (6) ). The two 1,1'-ferrocenylacetylene ligands coordinate exclusively in m 2 -h 1 h 2 type.…”