Arylmercury compounds formation

Aryl derivatives of the heavier group 6 derivatives can also serve for the synthesis of arylmercury compounds.52 For instance, treatment of the diaryltellurium complex 30 with HgCl2 leads to the formation of a coordination complex which undergoes a slow dismutation reaction to afford the arylmercury chloride derivative 31 and the corresponding tellurium species (Scheme 3).53... 

MeHg" " is distributed throughout the body, and easily penetrates the blood-brain and blood-placental barriers (Clarkson 1993, Hansen et al. 1989, Suzuki et al. 1984). The transport of MeHg" " into tissues is mediated by the formation of a MeHg-cysteine complex (Aschner and Aschner 1990, Tanaka et al. 1991, Kerper et al. 1992). Soon after application, McHg" " is found in the blood, predominantly in the red cells. In humans, the ratio of MeHg in red blood cells to serum is approximately 20 1 (Kershaw et al. 1980). Short-chain alkyl-mercury compounds such as methylmercury or ethylmercury are rather stable in the body, whereas long-chain alkylmercury or arylmercury compounds such as phenylmercury may be metabolized relatively quickly to Hg " " ions (Roberts et al. 1979) and, therefore, show similar behavior to the Hg " " ion (Pfab et al. 

Alkyl- and arylmercury(II) halides are used for the ketone formation[402]. When active methylene compounds. such as /f-keto esters or malonates are used instead of alcohols, acylated / -keto esters and malonates 546 are produced, For this reaction, dppf is a good ligand[403]. The intramolecular version of the reaction proceeds by trapping the acylpalladium intermediate with eno-late to give five- and six-membered rings smoothly. Formation of 547 by intramolecular trapping with malonate is an example[404]. 

Arylmercury(II) compounds have been shown575 to undergo substitution by Pd(II) salts with subsequent biaryl formation. The following mechanism was suggested ... 

---