Phenylmercurials

The isoflavone 406 is prepared by the indirect a-phenylation of a ketone by reaction of phenylmercury(II) chloride with the enol acetate 405, prepared from 4-chromanone[371]. A simple synthesis of pterocarpin (409) has been achieved based on the oxypalladation of the oriho-mercurated phenol derivative 408 with the cyclic alkene 407[372,373]. 

Pd(II) salts promote the carbonylation of organomercury compounds. Reaction of phenylmercury chloride and PdCh under CO pressure affords benzophenone (429)[387]. Both esters and ketones are obtained by the carbonylation of furylmercury(Il) chloride in alcohol[388]. Although the yields are not satisfactory, esters are obtained by the carbonylation of aryl- and alkylmercuryfll) chlorides[389,390]. One-pot catalytic carbonylation of thiophene, furan, and pyrrole (430) takes place at the 2-position via mercuration and transmetallation by the use of PdCb, Hg(N03), and CuCl2[391]. 

Acetoxymercurioxazoles (74AHC(17)99) and acetoxymercuriothiazoles with halogens give the corresponding halogenooxazoles in good yield. 4-Acetoxymercuriopyrazoles show many of the reactions of phenylmercury(II) acetate removal by HCI, conversion to Br by bromine, and to SCHjPh by (SCN)2/PhCH2CI. 

Dimethylpyrazole (L) reacts with mercury(II) chloride to give complexes of the structure L2(HgCl2)3. In connection with metallotropy (Section 4.04.1.5.1) the behaviour of compounds (295) has been described. These phenylmercury derivatives were synthesized by the action of phenylmercury hydroxide on the appropriate pyrazole (71MI40400). 

Phenylmercury halides give the corresponding phenylmercury derivative, CgH5HgC(CF3)3 (61%) [156], and perfluorocyclobutene gives the corresponding cyclobutyl derivative [156], Mechanistically, the reaction could be interpreted as formation of the fluorocarbanion via nucleophilic addition of fluoride ion to the fluoroolefin followed by capture of the intermediate fluorocarbanion by the mercury salt [156]. The regiochemistry of the reaction is consistent with this mechanism [156] (equation 119). 

Phenylmercury derivatives of 3-aminomethylene-l-methyloxindols have also been investigated (79KGS65). For studies of the effect of substituents on the electronic structure of silver and potassium salts of 3-(aryl)imi-nooxindole see 76MI2. The keto-enol and imino-enamine tautomerism of compounds of type 127 (with 128 and 129) has been investigated (85KGS921). 

Degenerate rearrangements of the l-phenylmercury-3,5-dimethylpyr-azoles 31 are apparently the first example of metallotropy in the series of azoles (71DOK110) (Scheme 15). 

The use of organotin compounds for the preparation of organometallics and organometalloids appears to be quite versatile.9 For example, alkyltetrafluorophosphoranes have been obtained from tetraalkyltin compounds and phosphorus(Y) fluoride,10 phenylmercury(II) chloride from tetraphenyltin and mercury(II) chloride,11 and divinylbromoarsine from ( -C4H9)2-Sn(CH=CH2)2 and arsenic (III) bromide.12... 

For bromide and iodide, the nature of the countercation influences the structure of the anionic complex. In fact, when the [(18-C-6)-K]Br and [(18-G-6)-K]I salts are used, the anionic complexes ([ 163—X]—, X = Br, I) remain mononuclear and adopt a T-shaped structure (Figure 11). In both cases, the Hg-X bonds are shorter than those observed in the corresponding dinuclear complexes in agreement with the terminal location of the anion. The reaction of bis(pentafluoro)phenylmercury 164 with [(18-C-6)-K]Br and [(18-C-6)-K]I also afford T-shaped complexes [164-Br] and [164-1]. The Hg-Br (2.93 A) and Hg-I (3.12 A) bonds found in these complexes are longer than those observed in [163-Br] and [ 163—1] indicating that 164 is a weaker Lewis acid than 163.206... 

Heck obtained 4-phenyI-3-acetoxy-l-butene (126) by the reaction of butadiene, phenylmercury acetate, and lead tetraacetate in the presence of a catalytic amount of Pd(OAc)2 (112) ... 

Preindustrial levels Lake contaminated with phenylmercury until 1967 0.18-0.33 FW 61... 

Kimura and Miller [28] collected and determined vapours produced by the decomposition in soil of phenyl alkylmercury compounds. They found that the air above soil containing phenylmercury acetate contained mercury vapour and traces of phenylmercury acetate. 

Kimura and Miller [29] have described a procedure for the determination of organomercury (methylmercury, ethylmercury and phenylmercury compounds) and inorganic mercury in soil. In this method the sample is digested in a steam bath with sulphuric acid (0.9M) containing hydroxy ammonium sulphate, sodium chloride and, if high concentrations of organic matter are present, potassium dichromate solution. Then, 50% hydrogen... 

Total mercury is determined in soils containing phenylmercury acetate and or ethylmercury acetate using the method described by Polley and Miller [31]. Total mercury is determined in soils containing methylmercury chloride and methylmercury dicyanamide by the method described by Kimura and Miller [32], Kimura and Miller [30] present chemical data on the nature of residual mercurials in soil and in the atmosphere surrounding the treated soil to further elucidate the phenomena of degradation in soil. 

They showed that metallic mercury vapour and trace amounts of phenylmercury acetate were present in the air surrounding phenylmercury acetate-treated soil. About equal amounts of the vapours... 

Table 13.9 Analyses of phenylmercury acetate (PMA)-treated soil... 

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