Organomercuric

The reaction of alkenyl mercurials with alkenes forms 7r-allylpalladium intermediates by the rearrangement of Pd via the elimination of H—Pd—Cl and its reverse readdition. Further transformations such as trapping with nucleophiles or elimination form conjugated dienes[379]. The 7r-allylpalladium intermediate 418 formed from 3-butenoic acid reacts intramolecularly with carboxylic acid to yield the 7-vinyl-7-laCtone 4I9[380], The /i,7-titisaturated amide 421 is obtained by the reaction of 4-vinyl-2-azetidinone (420) with an organomercur-ial. Similarly homoallylic alcohols are obtained from vinylic oxetanes[381]. 

The organomercury compounds can be used in situ or isolated as organomercuric halides. 

Organometallic formation may result from a chain mechanism [Eqs. (21)-(23) and (18)—(20)] and/or radical displacement [Eqs. (21)-(23), alone]. The reaction of 13C-labeled mercuric cyclohexanoate with cyclohexylcarbonyl peroxide (1 1) gave mainly unlabeled organomercu-rial, which was derived from radical displacement (122). Decarboxylation by a chain mechanism was reported for the syntheses of organomercuric carboxylates of straight chain alkyls [R = Me(CH2) , n - 0-8, 10, or 15 (123-131)], branched alkyls [R = Me2CH(CH2) , n = 0 or 2 (132) or Me3C(CH2) , n = 0-2 (133)], substituted alkyls [R = cyclopentylmethyl... 

Organomercuric compounds require nucleophilic assistance by soft iodide anions (cf. Section 9.6.3.2.2) for participation in cross-coupling reactions.158 The reaction is useful for aryl-aryl cross-coupling in those cases in which the organomercury species are obtained by direct mercuration of aromatic compounds (38).159... 

When either diacetyl of dibenzoyl peroxide is decomposed in benzene in the presence of metallic mercury an organomercuric salt is obtained.117 The reaction is similar to the mirror removing reaction observed in gas phase experiments. 

This simple, convenient procedure eliminates the use of strong acids which sometimes cause unwanted molecular rearrangements and the isolation and handling of toxic organomercuric halides. It also allows you to apply the borohydride reduction directly to the adduct, without precipitating it as the chloride. The main precursor is any allyl benzene eliminating the need for conversion to a propenyl benzene. 

Mercury(II) acetate is the starting material to prepare many organomercuric compounds. 

Another sort of difficulty occurs in the cleavages of organomercuric halides. Unrelated secondary reactions occur at rates which may be comparable with the rates of proton transfer. An example (Kreevoy and Kretchmer, 1964) is given in equations (47) through (51). The... 

Alkenes can be converted to ethers by the electrophilic addition of mercuric trifluoroacetate, followed by addition of an alcohol. An organomercuric intermediate is obtained that can be reduced with sodium borohydride to yield the ether ... 

Fig. Reaction of 2-methyl-l -propane with aqueous sulphuric acid. The same holds true for the organomercuric synthesis of alcohols ...

Broders [124] isolated from the nitration products an organomercuric compound to which he ascribed the following formula ... 

In closing, important advances have been performed after 1999 on Hg(II) photocatalysis, especially concerning the highly toxic organomercuric compounds. However, and as said in a previous paper (Botta et al., 2002), it is worthwhile to remark that remediation of Hg(II) in aqueous solutions is hard to attain completely, because of the low levels needed to avoid toxicity (in the order of gg L ). Thus, very sensitive analytical tools must be used to control the concentration of species in the solution. The physicochemical properties of the products derived from the treatment also introduce serious difficulties. Although zerovalent mercury can be carefully distilled off by mild heating, trapped and recondensed, or it can be dissolved with nitric... 

Toxicity of CrfVI) versus essentiality of Cr(III) Biomethylation with formation of toxic organomercuric compoimds... 

Diaryl or dialkyl ketones. Organomercuric halides react with nickel carbonyl in DMF or THF al 60-70 (20 hr.) to give ketones in high yield. Thus phcnylmercuiic chloride or bromide is converted into benzophenone in 92 95% yield ... 

The Razuvaev organomercuric synthesis gave us cr-chloromercuri-camphenilone via camphenonoyl peroxide. 

The initial syntheses of [18F] FDOPA were done using direct electrophilic fluorination of DOPA [49], which was soon replaced with methods for regioselective 18F-fluorination of DOPA using organomercuric [50] or organostannane precursors [51] (Figure 14.5). 

This is shown by the first sequence in Scheme 4.4 6 the organomercuric precursor in this case was constructed by a double alkoxymercuration reaction. Addition of sodium chloride caused the formation of the organomercuric chloride this is usually insoluble and merely separated by filtration. An... 

Ketone synthesis. Many organomercuric halides react with dicobalt octacarbonyl in THF solution at room temperature to give symmetrical ketones ... 

Another method of preparation of a cyclometallated complex is through transmetallation, for example, substitution of Li in a lithiated compound, or through organomercuric derivatives [33,34], This reaction led to the first homoleptic bis-cyclometallated complex, Pt(ppy)2 [35]. The reaction sequence is shown in Eq. (2) ... 

---