Arylation organomercury compounds

Addition of several organomercury compounds (methyl, aryl, and benzyl) to conjugated dienes in the presence of Pd(II) salts generates the ir-allylpalladium complex 422, which is subjected to further transformations. A secondary amine reacts to give the tertiary allylic amine 423 in a modest yield along with diene 424 and reduced product 425[382,383]. Even the unconjugated diene 426 is converted into the 7r-allyllic palladium complex 427 by the reaction of PhHgCI via the elimination and reverse readdition of H—Pd—Cl[383]. 

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]. 

Organomercury compounds undergo a similar reaction. Alkyl and aryl Grignard reagents can be converted to carboxylic esters with Fe(CO)5 instead of CO. Amides have been prepared by the treatment of trialkyl or triarylboranes with CO and an imine, in the presence of catalytic amounts of cobalt carbonyl ... 

Cappon and Crispin-Smith [59] have described a method for the extraction, clean-up and gas chromatographic determination of alkyl and aryl mercury compounds in sediments. The organomercury compounds are converted to their chloroderivatives and solvent extracted. Inorganic mercury is then isolated as methylmercury upon reaction with tetramethyltin. The initial extract is subjected to a thiosulphate clean-up and the organomercury species are isolated as their bromoderivatives. Total mercury recovery was in the range 75-90% and down to lpg kg-1 of specific compounds can be determined. 

Organomercury compounds undergo a similar reaction.388 Alkyl and aryl Grignard reagents can be converted to carboxylic esters with Fe(CO)s instead of CO.389... 

Over 35 years ago, Richard F. Heck found that olefins can insert into the metal-carbon bond of arylpalladium species generated from organomercury compounds [1], The carbopalladation of olefins, stoichiometric at first, was made catalytic by Tsutomu Mizoroki, who coupled aryl iodides with ethylene under high pressure, in the presence of palladium chloride and sodium carbonate to neutralize the hydroiodic acid formed (Scheme 1) [2], Shortly thereafter, Heck disclosed a more general and practical procedure for this transformation, using palladium acetate as the catalyst and tri-w-butyl amine as the base [3], After investigations on stoichiometric reactions by Fitton et al. [4], it was also Heck who introduced palladium phosphine complexes as catalysts, enabling the decisive extension of the ole-fination reaction to inexpensive aryl bromides [5],... 

The R2Zn compounds may be obtained in several ways (1) by reactions of ZnCl2 with RLi, R2Mg, or R3AI compounds (2) for the aryls especially, the reaction of the metal with an organomercury compound ... 

Organomercury compounds, such as aryl and alkoxy-aryl, have been used in medicine, agriculture, and laboratory research. Their use in fungicides has been greatly reduced or eliminated. 

Organomercury compounds can also be obtained in preparatively useful quantitites by the action of radicals on metallic mercury. For example, aryl-mercuric compounds are formed on decomposition of arenediazonium salts in the presence of metallic mercury 28 and when 3-iodopropionitrile is reduced electrolytically at a mercury cathode, the radicals produced react with the cathode material forming bis-(2-cyanoethyl)mercury.202 Organomercury compounds are also obtained analogously on reduction of ketones at a mercury cathode.203... 

Organomercury compounds 538 have been synthesized by the reaction of barbituric acid or thiobarbituric acid derivatives 67 (X = O, R = H X = S, R = Ph) with aryl mercuric chloride under MWI using basic alumina as a solid support less time (1.5 2 min) and better yields (90 96%) (Scheme 106) were found as compared to the conventional method (99POL2641). 

Mixed-metal catalysts based on 002(00)9 have proved effective In the synthesis of N acyl amlnoaclds, starting with either allylic alcohols, oxiranes (eqn.15) or trifluoropropene. The oxidative carbonylatlon of organomercury compounds Is subject to solvent effects. The Pd catalysed carbonylative cross-coupling of aryl Iodides with triIsobutylaluminium gives secondary benzyl alcohols a variety of functional groups are tolerated.Carbamate esters... 

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... 

A functionalized mercury(II) compound like ethyl (acetoxymercurio)acetate (136) allows an easy approach to prostaglandin endoperoxide analogs (equation 52).204 Several organomercury(II) compounds, RHgCl (R = Me, aryl, benzylic), are able to add to 1,3-dienes in the presence of a stoichiometric amount of a palladium(II) salt and affonl ir-allylpalladium compounds of type (137) in variable yields (equation 53).20S A related intramolecular carbomercuration has been reported by Snider.206 It allows a stercospe-cific approach to the chloromercury compound (138 equation 54). Similar palladium-mediated reactions... 

The synthesis of alkyl(aryl)chlorosilanes, based on the use of metalorganic compounds, can be carried out with the help of organomercury, organoz-inc, organosodium, organolithium, organoaluminum and organomagne-sium compounds. 

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