- On the synthesis and structure of monoaryllead and diaryllead acetates RPb(OCOCH3)3 and R2Pb(OCOCH3)2
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Anhydrous monoaryllead triacetates ArPb(OAc)3 (Ar = Ph, p-Tolyl, o-Tolyl, 2,5-Xylyl; OAc = OCOMe) were prepared by arylation of Pb(OAc)4 with ArSn(C4H9-n)3 in the presence of Hg(OCOCF3)2. The procedure was adapted for the synthesis of diaryllead diacetates Ar2Pb(OAc)2 (Ar = Ph, p-Tolyl, o-Tolyl, p-ClC6H4, o-ClC6H4) and afforded products with higher purity than other procedures. The crystal structures of PhPb(OAc)3, Ph2Pb(OAc)2 and (o-Tolyl)2Pb(OAc)2 were determined by X-ray diffraction. PhPb(OAc)3 and (o-Tolyl)2Pb(OAc)2 are monomeric. The pentagonal bipyramid around Pb in PhPb(OAc)3, like the trapezoidal bipyramid around Pb in (o-Tolyl)2Pb(OAc)2, is heavily distorted, the OAc groups being unsymmetrically chelating. Lead in Ph2Pb(OAc)2 is in a distorted octahedral environment. One OAc group is bridging, linking the molecular units to infinite chains, the other OAc group is symmetrically chelating. IR, 1H, 13C and 207Pb NMR spectroscopic data are reported. The structures of p-TolPb(OAc)3, o-TolPb(OAc)3 and 2,5-XylPb(OAc)3 are inferred to be similar to that of PhPb(OAc)3, and the structure of (o-ClC6H4)2Pb(OAc)2 is inferred to be similar to that of (o-Tolyl)2Pb(OAc)2.
- Schuermann, Markus,Huber, Friedo
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p. 121 - 130
(2007/10/03)
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- Reaction of Arylboronic Acids and their Derivatives with Lead Tetra-acetate. The Generation of Aryl-lead Triacetates, and meta- and para-Phenylenebis(lead triacetate), in situ for Electrophilic Arylation
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Arylboronic acids and some of their derivatives have been found to undergo a rapid boron-lead exchange with lead tetra-acetate.In the presence of a catalytic amount of mercury(II) acetate, the reaction produces mainly the aryl-lead triacetate, and it has been developed as a convenient method for in situ generation of these useful electrophilic C-arylating reagents.The reaction allows the generation for the first time of meta- and para-phenylenebis(lead triacetate), compounds which behave as meta- and para-phenylene dication equivalents.
- Morgan, Jacqueline,Pinhey, John T.
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p. 715 - 720
(2007/10/02)
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