Silver organosilver compounds

Kauffmann and coworkers have described the reaction of alkylsilver compounds with cyclohexenone (Scheme 1.6).29 It was found that the alkylsilver derivatives reacted preferentially, and in some cases exclusively, in the (3 position. A significant amount of 3-methylcyclohex-2-enol was observed for the reaction of Me2AgMgBr, which has been attributed to the elimination and subsequent reaction of silver(I) hydride. Silver(I) hydride has been observed in the gas-phase fragmentation of other organosilver compounds.30... 

As is general for organosilver compounds, perfluorophenylsilver is considerably more stable than phenylsilver.55 The first example of a perfluoroarylsilver compound was reported by Miller and Sun in 1970.49 Reaction of perfluorophenyllithium with silver trifluoroacetate, or of perfluorophenyl bromide with perfluoroisopropylsilver, gave perfluorophenylsilver as colorless crystals (Scheme 1.17). The compound was found to be stable up to 150°C, at which temperature it slowly dimerized to give perfluorobiphenyl and metallic silver. Since this initial report a number of syntheses of perfluorophenylsilver from perfluorophenyllithium followed.56,57... 

The use of silver acetylides to effect useful synthetic transformations has been perhaps more widely reported than the use of any other organosilver compound, as previously reviewed by Pale et al.81 and Sladkov et al.82 Their use, however, in comparison to that of other metal acetylides (Na, Cu, Li), has perhaps been limited by their relatively low reactivity and/or solubility. The silver acetylides are, however, generally comparatively more stable than the more commonly used metal acetylides, as they can be... 

Silver acetylides undergo oxidative condensation in the presence of cupric chloride to give diynes.124 Dimerization is a reaction common to a number of organosilver compounds, including both alkyl- and arylsilver derivatives. 

Schmidbaur, H. Bayler, A. Synthesis and uses of organosilver compounds, in The Chemistry of Organic Derivatives of Gold and Silver, Patai, S. Rappoport, Z., eds., Wiley, Chichester, UK, 1999, pp. 211-226. 

Chelation has been used to stabilize organosilver compounds. The compound 2-[(dimethylamino)methyl]-phenyl silver, a chelate involving N and C coordination, melts at 180 °C. The adduct with AgBr is light and air stable for 10 days. The product from LiBr was the first example to contain bridging phenyl groups. It decomposes at 180°C but is air and moisture sensitive. 

The transmetallation reaction between AgBF4 and a tertiary bis(silyl)pyridylmethylh-thium compound afforded the dinuclear alkylsilver species (1), which is stable at room temperature for several days7. Despite the susceptibility of most organosilver compounds to hydrolysis, the argentate complex with a /S-disulphone carbanion (2) can be obtained by the reaction of 1,3-dithiane 1,1,3,3-tetraoxide with silver nitrate in alkaline aqueous solution8. 

A number of review articles dealing with organosilver chemistry have appeared since 19701-4. The present chapter is confined to compounds in which the organic group is bound to silver as one-electron ligand. 

Organosilver complexes with yUde hgands have been prepared in a variety of ways. Most of them are remarkably inert with respect to hydrolysis and thermal decomposition, representing some of the most stable organometaUic compounds of silver. The identity and structure of the compounds have been determined either by X-ray diffraction or by multi-nuclear NMR spectroscopy, where the observation of large C-, H- and P- O /io Ag coupling constants is indicative for a structure with the yhde attached to the metal centre through the carbanionic donor atom. 

Stable organosilver derivahves of chloroferrocene have been prepared by the reaction of the corresponding boronic acid with silver salts in aqueous ammonia solution (equation 32) 2-Silver(dimethylaminomethyl)ferrocene has been obtained by trans-metallation between silver bromide and the corresponding lithium ferrocenyl compound. ... 

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