Organomercurials reactions with

Organomercury compounds, reaction with NaBH4, 222 Organometallic compound, 345 polarity of, 143... 

Organomercury reagents do not react with ketones or aldehydes but Lewis acids cause reaction with acyl chlorides.187 With alkenyl mercury compounds, the reaction probably proceeds by electrophilic attack on the double bond with the regiochemistry being directed by the stabilization of the (3-carbocation by the mercury.188... 

Other Cyclopropanation Methods. Haloalkylmercury compounds are also useful in synthesis. The addition reactions are usually carried out by heating the organomercury compound with the alkene. Two typical examples are given in Section C of Scheme 10.9. 

Figure 6.28 Photoinduced reaction of an organomercury compound with a dialkyl phosphate salt.

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. 

Perlmutter used an oxymercuration/demercuration of a y-hydroxy alkene as the key transformation in an enantioselective synthesis of the C(8 ) epimeric smaller fragment of lb (and many more pamamycin homologs cf. Fig. 1) [36]. Preparation of substrate 164 for the crucial cyclization event commenced with silylation and reduction of hydroxy ester 158 (85-89% ee) [37] to give aldehyde 159, which was converted to alkenal 162 by (Z)-selective olefination with ylide 160 (dr=89 l 1) and another diisobutylaluminum hydride reduction (Scheme 22). An Oppolzer aldol reaction with boron enolate 163 then provided 164 as the major product. Upon successive treatment of 164 with mercury(II) acetate and sodium chloride, organomercurial compound 165 and a second minor diastereomer (dr=6 l) were formed, which could be easily separated. Reductive demercuration, hydrolytic cleavage of the chiral auxiliary, methyl ester formation, and desilylation eventually led to 166, the C(8 ) epimer of the... 

Pyridyl-phosphorus and -arsenic compounds have also been made by nucleophilic displacement reactions with, for example, 3-pyridinediazonium salts (74HC(14-2)489). Organomercury derivatives can be converted into bromides and iodides by standard methods, e.g. Scheme 147 (59JPR(8)156). 

Treatment of l-(mercaptoalkyl)silatranes with organomercury acetate in chloroform affords the corresponding mercury derivatives in 80-85% yield (equation 148). A related reaction with diorganylmercury results in lower product yields372. 

Bipyridine-derived cycloaurated complexes have also been synthesised through the transmetallation route. Conversion of 6-phenyl-2,2 -bipyridine to its organomercury derivative 58, followed by reaction with Na[AuCl4] gave the cycloaurated complex 59 in 38% yield as its [AuC14] salt.39... 

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