Mercury aryl derivatives

Studies of interactions between tetranitromethane and aryl derivatives of magnesium, tin, and mercury in sulfolane (Shevelyov et al. 1974, 1975) confirm that NO2 radical has some slight activity. For example, the reaction of diarylmercury with tetranitromethane passes through a transient step with the formation of radicals Ar and NO2. These radicals almost do not interact ... 

Nitrogen dioxide plays an important role in the reaction. It is this compound that is responsible for the conversion of mercury aryl nitrates into nitroso derivatives. 

A similar reaction consists of decomposition of the double salt of a diphenyl-halonium salt and a heavy-metal halide by a powdered metal (Reutow). It can be used for synthesis of aryl derivatives of a wide variety of metals such as mercury, tin, antimony, and bismuth.23... 

Solutions of sodium metal in liquid ammonia are blue and have high electrical conductivities the main current carrier of such solutions is the solvated electron. Such solutions are used in both organic and inorganic chemistry as efficient reducing agents. Sodium also forms a number of alkyl and aryl derivatives by reaction with the appropriate mercury compound, e.g. ... 

Galen, a physician whose views outUved him by about a thousand years, died about 200 AD. He beUeved that mercurials were toxic, and did not use any mercury compound therapeutically. However, as a result of Arabian influence, the therapeutic uses of mercury were slowly recognized by Western Europe. In the thirteenth century mercury ointments were prescribed for treating chronic diseases of the skin. Mercury and its compounds, such as mercurous chloride, mercuric oxide, mercuric chloride, and mercuric sulfide, were used widely from the fifteenth to the nineteenth centuries, and to some extent in the twentieth century. During the first half of the twentieth century, the primary therapeutic uses of mercury included bactericidal preparations, such as mercuric chloride, mercuric oxycyanide, and mercuric oxide and diuretics, such as aryl HgX (Novasural) and mercurated ahyl derivatives (14). 

The reaction of heterocyclic lithium derivatives with organic halides to form a C-C bond has been discussed in Section 3.3.3.8.2. This cannot, however, be extended to aryl, alkenyl or heteroaryl halides in which the halogen is attached to an sp2 carbon. Such cross-coupling can be successfully achieved by nickel or palladium-catalyzed reaction of the unsaturated organohalide with a suitable heterocyclic metal derivative. The metal is usually zinc, magnesium, boron or tin occasionally lithium, mercury, copper, and silicon derivatives of thiophene have also found application in such reactions. In addition to this type, the Pd-catalyzed reaction of halogenated heterocycles with suitable alkenes and alkynes, usually referred to as the Heck reaction, is also discussed in this section. 

Electrochemical reduction, though a little-used method, defluorinates aryl fluorides to the corresponding hydrogeno derivatives. 1,3-Difluorobenz.ene is reduced at a mercury cathode to give a mixture of fluorobenzene and benzene,54 while the reduction of perfluorobenzene at an... 

Vinyl substitution occurs with conjugated dienes as well as with alkenes, employing aryl-, vinyl-, methyl-, alkoxycarbonyl- or benzyl-mercury reagents and lithium tetrachloropalladate(II), but the products are usually rr-allylpalladium complexes if the reactions are carried out under mild conditions (equation 8).24,25 The ir-allylic complexes may be decomposed thermally to substituted dienes26 or reacted with nucleophiles to form allylic derivatives of the nucleophile. Secondary amines, for example, react to give tertiary allylic amines in modest yields, along with dienes and reduced dienes (equation 9).25... 

Arylmercuric halides may be used in place of diarylmercurials. Excellent yields, often 90-98%, were obtained in many cases. Table III lists some examples. Oxidative degradation studies of selected products showed that the aryl carbon atom originally attached to mercury was the one that became bonded to the apical carbon atom of the cluster. This reaction was much less useful in the preparation of alkyl derivatives, because of very long reaction times (1-2 weeks) giving at best moderate yields (Table III). The reaction of a-haloalkylmercurials with HCCo3(CO)9 occurred... 

Aromatic fluorinations of other activated rings were also performed. Thus, m-dimethox-yarenes were mono- and di-fluorinated (equation 136)242. Aryl mercury and aryltin derivatives were successfully reacted with CF3OF as well forming the corresponding fluoro derivatives (equation 136)243. 

N—C—O + C—C. The construction of the oxazole ring by the condensation of a-halogeno ketones with primary amides (equation 122) is the Bliimlein-Lewy synthesis (1884/1888). The method succeeds best when the resulting oxazole contains one or more aryl substituents. The use of formamide leads to oxazoles with a free 2-position and in this case it is possible that the reaction proceeds as in equation (113). 2-Aminooxazoles are produced by the action of a-halogeno ketones on urea and its derivatives (equation 123) or on cyanamide (80ZOR2185). The mercury(II) sulfate-catalyzed condensation of alkynic alcohols or their esters with primary amides leads to trisubstituted oxazoles (equation 124). 

Another synthetic route to monoorganothallium compounds is the reaction of aryl or vinyl derivatives of mercury(II) or tin(IV) with TIX3 (X = halide, carboxy-late). Monoalkylthallium derivatives are intermediates m the oxidation of alkenes and alkynes by thallium(III) salts (oxythallation) (see Section 7). 

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