Carbene complexes of gold

Raubenheimer, H.G., Lindeque, L. and Cronje, S. (1996) Synthesis and characterization of neutral and cationic diamino carbene complexes of gold(I). Journal of Organometallic Chemistry, 511 (1-2), 177-184. 

The interest in functionalised carbene complexes of gold(I) derives not only from the longer known biological applications [21-23], but also from a recent interest in their performance in catalysis [14,15,24,25]. Ray et al. tested a series of nonfunctionalised, hydroxy functionalised and hydroxy/keto difunctionalised NHC ligands in the ROP of L-lactide [14]. There is no significant difference in the activities of the two functionalised NHC... 

Cyclopropanation progressed through a cyclopropyl methyl carbene complex of gold 312, which is active toward further cyclopropanation with an intramolecular alkene unit. Echavarren and coworkers reported that dienyne compounds 311 gave tricyclic cyclopropanes 313 in good yields (Scheme 1.153) [220]. 

Uson, R., Laguna, A., Vicente, J., Garcia, J., Bergareche, B. and Brun, P. (1978) Neutral isocyanide and carbene pentafluorophenyl complexes of gold(l) and gold(lll). Inorganica Chimica Acta, 28 (2), 237-243. 

Desmet, M., Raubenheimer, H.G. and Kruger, G.J. (1997) Synthesis and Characterization of Thienyl Oligomeric, Carbene, and Nitrogen-Donor Complexes of Gold(I). Organometallics, 16(15), 3324-3332. 

A series of dinuclear gold(I)-carbene complexes of imidazolium-linked cydo-phanes and related acyclic bis(imidazolium) salts have been synthesized and their spectroscopic properties were examined by Baker and coworkers [31]. X-ray stmctural analysis of the cation in 1 and 2 (Scheme 5.1) revealed intramolecular Au - Au contacts of 3.5425(6) and 3.0485(3) A respectively. The electronic absorption... 

N==Ca+—Aua which makes the isocyanide ligands susceptible to nucleophilic attack and has led to formation of carbene complexes, iminoalkyl complexes and catalytic conversion of isocyanides to formamidines using alkyl or aryl isocyanide complexes of gold(I).301,402 4(y7-409-415 A review of this significant work has been published.16... 

Gold(I) isonitrile complexes were first reported (131) in 1956, when it was found that they were generally less stable than the isonitrile complexes of other transition metals. This was attributed to the low tendency of gold to form bonds with double bond character. A number of isonitrile complexes have been made, however, and they have been used extensively in the preparation of carbene and imino complexes of gold(I). 

Similar carbene complexes of silver(l) and gold(l) are observed when catechole is used as the scaffold. Synthesis of the bis-imidazohum salt follows the established protocol with bis-iodoethyl catechole and A-(l-naphthylmethyl)-imidazole as the starting materials [214], Reaction with silver(l) oxide and subsequent carbene transfer to copper(l) iodide yields the corresponding silver(l) and copper(l) carbene complexes. 

IV. SYNTHESIS AND PROPERTIES OF ALKENE, ALKYNE, CARBENE AND RELATED COMPLEXES OF GOLD... 

TOWARDS THE SYNTHESIS OF CARBINE COMPLEXES OF GOLD AND COPPER CARBENE COMPLEXES... 

P. Chen Gas-phase synthesis and reactivity of a gold carbene complex a gold benzylidene complex ion was observed, corresponding to the presumed reactive intermediates of a gold-catalyzed cyclopropanation reaction. [220]... 

Organometallic complexes of copper, silver, and gold are ideal precursors for carbene complexes along with some C- and N-coordinated species. Their reactivity pattern, in particular in oxidative addition reactions, was the most comprehensively studied. 

Gold carbene complexes preparation, oxidation, and ligand displacement. Journal of Organometallic Chemistry,... 

Raubenheimer, H.G., Scott, F., Roos, M. and Otte, R. (1990) The synthesis of gold (1) carbene complexes using 4-methylthiazolyllithium. Journal of the Chemical Society, Chemical Communications, (23), 1722-1723. 

Barnard, P.J., Baker, M.V., Bemers-Price, S.J., Skelton, B.W. and White, A.H. (2004) Dinudear gold(I) complexes of bridging bidentate carbene ligands Synthesis, structure and spectroscopic characterisation. Dolton Transactions, 1038-1047. 

Ishii, R., Kaharu, T., Pirio, N., Zhang, S.-W. and Takahashi, S. (1995) Liquid-crystalline gold(I)-carbene complexes. Journal of the Chemical Society, Chemical Communications, (12), 1215-1216. 

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