Alkynyllead triacetates

Alkynyllead triacetates.1 Pb(OAc)4 reacts with a 1-alkynyltrimethyltin to form trimethyltin acetate and an unstable 1-alkynyllead triacetate (a), which can effect alkynylation of (i-dicarbonyl compounds and nitronates. In general yields are highest with R = QH, and lowest with R = H. 

Alkynyllead triacetates can be prepared by tin-lead or by mercury-lead exchange.88,8811 However, more convenient methods were subsequently devised. In situ transmetallation can be directly realized by lithium-lead or zinc-lead exchange. This avoids the isolation of unstable alkynylmetal derivatives. Ikegami et al. found that, if a THF solution of... 

Alkynylation of enolates was used to prepare optically active 13,14-didehydroisocarbacyclin. Preparation of the optically active (Ai-alkynyllead triacetate was compatible with the lithium-lead tetraacetate metal-metal exchange (Scheme 11 and Equation (66)).91... 

Alkynyllead triacetates can be prepared by metal-metal exchange between lead tetraacetate and either dialkynylmercury or alkynyltrimethyltin derivatives. A straightforward and more... 

It was also shown that aryl- and alkynyllead triacetates could be converted to biaryls and diynes in the Pd-catalyzed reaction (Table... 

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