Plumbyls reactions with

Lead(IV) trifluoroacetate in TFAH is a very reactive electrophile that is capable of plumbylating less electron-rich arenes. Nonetheless, the use of trifluoroacetate anions in the plumbylation reactions should be avoided, because aryllead(IV) tri-fluoroacetates are unstable compounds that readily decompose to the corresponding aryl trifluoroacetates and biaryls [34—37, 40, 41]. It has been reported [41] that 4-FC6H4ArPb(TFA)3 is reasonably stable and can be isolated from the reaction of Pb(TFA)4/TFAH with fluorobenzene. A mechanistic study [41] indicated an electrophilic substitution path for the plumbylation reaction, which seemed to be substantially more para-selective than mercuration and thallation. For example, the plumbylation of toluene with Pb(OAc)4 in dichloroacetic acid has been reported [41] to occur with >90 % para-selectivity. 

In 1958, Panov and Kocheshkov1216 found another route to the formation of the C—Pb bond, namely the interaction of tetraacyloxyplumbanes with aromatic and heteroaromatic compounds (the plumbylation reaction). They showed that the reaction of thiophene with Pb(OCOPr-i)4 at room temperature during 10 days led to unstable RPb(OCOR/)3 (R = 2-thienyl R = i-Pr), which was disproportionated to R2Pb(OCOR/)2 and Pb(OCOR/)4-... 

Methyl trimethylsilyl tellurium and phenyl trimethylsilyl tellurium exchanged the organyltelluro group for halogen in reactions with silyl, germyl, stannyl and plumbyl halides2. 

Scheme 19 Reactions of stannyl and plumbyl ditbiocarboxylates with amines and sodium metboxide...

Arenetellurolates reacted with triphenyl germyl, stannyl, and plumbyl chlorides12 18, but not with triphenylsilyl chloride or triphenylmethyl chloride16 17. However, reactions of... 

While plumbylation with lead tetraacetate does not occur for thiophene, the presence of electron-withdrawing groups in the acid moiety produces reaction. Thus, with one ligand replaced by dichloroacetate, a 63% yield of 2-thiophenelead triacetate is obtained (74TL853). Another... 

ArPb(OzC-CF3)2 Ar+ + Pb(02C CF3)2]. The aryl cations have been trapped with aromatic compounds to give biaryls [with certain substrates, notably poly-methylbenzenes, high yields (up to 88 %) are obtained], but with reactive aromatic substrates aryl cations are not the precursors to the biaryls and in these cases it is proposed that reaction proceeds via preliminary complex formation between the substrate and a species which contains an aryl-lead bond. Oxidative coupling of methyl-substituted benzenes by the reagent Pb(0Ac)4-CFs C02H to give biaryls and diarylmethane is also considered to involve formation of a radical cation in the primary step. A study has also been made of the plumbylation of monohalogeno-benzenes with Pb(OAc)4-CF3 COsH. ... 

The aryllead(IV) tricarboxylates can be prepared, among several possible routes, the most conveniently by the reaction of aryltri-n-butylstannanes [66], or arylboronic acids [67] with lead(IV) acetate in the presence of mercury(II) trifluoroacetate as the catalyst, or, in the case of electron-rich arenes such as polyalkoxybenzenes, by direct plumbylation with Pb(OAc)4 or its derivatives. Scheme 32. 

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