Mercury organo- compounds preparation

In many syntheses activation is not effected by sonochemical preparation of the metal alone but rather by sonication of a mixture of the metal and an organic reagent(s). The first example was published many years ago by Renaud, who reported the beneficial role of sonication in the preparation of organo-lithium, magnesium, and mercury compounds [86]. For many years, these important findings were not followed up but nowadays this approach is very common in sonochemistry. In another early example an ultrasonic probe (25 kHz) was used to accelerate the preparation of radical anions [87]. Unusually for this synthesis of benzoquinoline sodium species (5) the metal was used in the form of a cube attached to the horn and preparation times in diethyl ether were reduced from 48 h (reflux using sodium wire) to 45 min using ultrasound. 

Cognate preparation. 1-Phenylethanol. Use 10.4g (11.5ml, 0.1 mol) of styrene, and carry out the oxymercuration and reduction as described above. The yield of recovered mercury is 17.5 g (87%), and traces continue to separate during the work-up procedure. Distil the final crude product under reduced pressure and collect the 1-phenylethanol at 110-115 °C/25mmHg. Towards the end of the distillation the decomposition of residual organo-mercurial compounds ensues, and co-distillation of mercury contaminates the product collect the contaminated fraction separately. The first fraction, yield 6.2 g (51%), is 92 per cent pure by g.l.c. (retention time 5.33 minutes) the impurity is mainly styrene (tR 2.16 minutes). The mercury-contaminated fraction (3.0 g, 25%) is 85 per cent pure by g.l.c. 

The preparation of organopalladium compounds by exchange reactions of palladium salts and organo-lead, -tin, or -mercury compounds is apparently not the only way that they can be obtained but it does seem to be the most useful way. Convincing evidence is now available to show that direct metalation of aromatic compounds with palladium salts (palladation) can occur. Since the initial report of Cope and Siekman 32> that palladium chloride reacted readily with azobenzene to form an isolable chelated, sigma-bonded arylpalladium compound, several additional chelated arylpalladium compounds have been prepared. 

Tetraaryl tellurium compounds were prepared from tellurium tetrachloride and lithium halide-free organo lithium compounds3 7. Lithium halide-free organic lithium compounds were synthesized from diaryl mercury and lithium8. 

The principal utility of dialkyl- and diaryl-mercury compounds, and a very valuable one, is in the preparation of other organo compounds by interchange, e.g.,... 

In a process that served for the preparation of the first organoaluminum compound (1865),230 the trialkyl and, more so, the triaryl compounds can be conveniently obtained by treating metallic aluminum with the relevant organo-mercury compound.147,231,232 This method is too expensive when large... 

It is expected that endothermic or weakly exothermic organometallic compounds will be the most versatile reagents RM in such reactions. Such compounds are found among the heavy B elements (Hg, Tl, Pb and Bi). Of these the air-stable and readily prepared (though toxic) organo-mercury compounds are the most widely used. Let us consider the heats of reaction between dimethyl mercury and zinc and cadmium ... 

These compounds are the most stable of the three classes of organothal-lium(III) derivatives and have been prepared by a wide variety of classical organometallic procedures. Many exchange reactions of TIX3 (X = Cl, carboxylate) with organo derivatives of boron, mercury, tin, lead, etc., have been shown to result in formation of R2TIX compounds 73, 78), but are of relatively little preparative significance. The most frequently used procedure... 

Commercial products are often unsatisfactory in kinetic studies. Preparation of some commonly used initiators is given elsewhere141. Benzyl sodium is prepared from mercury dibenzyl and metallic sodium123 a similar technique yields barium and strontium salts. Fluorenyl lithium, sodium etc., are conveniently prepared from fluorene and a suitable organo-metallic compound, e.g. 

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