Aryl gold complexes

Severa] other gold complexes with Au-Au bonding contacts have been prepared and characterized The cyclic structure 51 was proposed on the basis of NMR and Au Mossbauer data Cation 52 was an early bridged aryl-gold complex to receive full X-ray structural characterization The acute Au-C-Au angle and the bond distances are characteristic features of such complexes and very close to those determined for dication 53 ... 

Alkene complexes Alkynyl complexes Ammine complexes Aqueous chemistry Arsine complexes Auranofin Auride ion Aurophilicity Binary compounds Bond lengths acetylacetonate complex alkyls and aryls ammine complexes carboxylates cyanide complexes dialkyl sulphide complexes dithiocarbamates to gold... 

The compound 86 constitutes an interesting compound in which a bis keto-ylide coordinates both a palladium (through an aryl and an ylidic carbon) and a mercuric center (through an yfidic carbon) [89,110]. This C,C,C-terdentate coordination has also been observed with gold complexes. 

Complexes of the type [AuRL] may contain a great variety of organic ligands such as alkyl, aryl, vinyl, or alkynyl, whereas the neutral donor ligand L is most commonly a tertiary phosphine. Also many polynuclear complexes are known which have the C-Au-L moiety with bridging polyfunctional ligands. Alkyl- or aryl-gold(I) complexes are usually synthesized... 

Salts of the type PPN+[C6F5AuC1] can be converted into the acetylacetonate PPN+[C6F5Au(acac)], and finally into the mixed aryl(ethynyl)gold(i) complex using Tl(acac) and C2H2, respectively. The same sequence applies to the 2,4,6-trinitro-phenyl-(picryl) and 2-nitro-phenyl-gold complexes.73... 

Thallium Adducts of Arylplatinum and -gold Complexes 3.08.9.5.1 Platinum aryl complexes... 

A common synthetic method is that of equation (9), where X = MeC02,168 PhS03,169 NO3170 or C104,171 and relies on the precipitation of silver chloride. A variation of this method is the synthesis of the ring complex (5), by the reaction (10).172 In other cases, the synthesis may involve mercury(II) salts or sodium salts (equations 11 and 12).173,174 Another useful synthetic method involves reaction of alkyl- or aryl-gold(I) complexes with carboxylic acids or acid anhydrides (equations 13-15).176,177... 

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... 

Its crystal structure shows a beautiful Au6Ag wheel in which the six gold atoms form a hexagon with the silver atom in the center (Fig. 26). As observed in other aryl bridging complexes,27 83 110 143 145 the planar tris(isopropyl)phenyl groups are nearly perpendicular to the mean plane through the metallic atoms. The Au-C distances, with values between 2.111(7) and 2.200(7) A, are also similar to those in the previously mentioned mesityl complexes. 

It has been noted that metal-carbon triple bonds behave in a similar way as alkynes with respect to jr-complex formation13,15. Various heterometallic gold complexes with bridging carbyne ligands reflect this analogy. Alkylidyne complexes like [W(=CR)(CO)2( 5-C5H5)], [W(=CR)(CO)2( 75-C2B9H9R )] (R = alkyl, aryl, amino R = H, Me) readily... 

Hydroarylation can also be mediated by Au(I) and Au(III) (Scheme 33) (384). In the case of aryl substituted alkynes, the Au(III) Ji complex undergoes electrophilic aromatic substitution with the electron-rich arene to give aLkenyl-Au(III) complex, which is immediately protonated by the H generated upon C C bond formation. For the Au(I)-catalyzed hydroarylation, the cationic gold complex k coordinates the alkyne, with subsequent nucleophilic attack by the arene from the opposite face leading to an alkenyl-gold complex, which is protonated to the desired products. The nature of the reaction causes the regioselectivity of this reaction to be sensitive to electronic rather than steric factors. 

Reductions. Ketones are reduced with trialkoxysilane-histidine complexes. A gold complex (Ph,P)AuCl catalyzes hydrosilylation of the C=0 group. Dibenzenechromium > a preeatalyst in the reduction of aryl carbonyl compounds." A system comprising... 

The popularity of the biphenyl moiety in many ligands is not a mere result of adding bulk. The second aryl ring, twisted at an angle to its partner, may affect the metal directly by coordination, as in the cationic gold complex (Figure 1.10). ° The X-ray structure (anionic counter ion not shown) clearly shows the proximity of the second ring to the metal atom. 

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