19008-96-9Relevant academic research and scientific papers
Kinetics of the protodestannvlation of allenyltins
Cochran, John C.,Kuivila, Henry G.
, p. 97 - 103 (2008/10/08)
Rate studies have been carried out on the protodestannylation reaction in methanol-4% water for five allenyltins. Substituents were varied in both positions on the allene skeleton as well as on tin. The reaction involves a competition between SE2 and SE2′ mechanisms leading to allenic and acetylenic hydrocarbon products, respectively. Electrophilic displacements by chlorine, bromine, and 2,4-dinitrobenzenesulfenyl chloride have also been studied. The NMR spectra of a number of allenic and isomeric propargylic derivatives are reported. In the protodestannylation reaction the allenyltins have been shown to be stable with respect to equilibration to the isomeric propargyltin. The SE2′ reactivity of the allenyltins is very similar to the SE2′ reactivity of allyltins. However, in the SE2 reaction the allenyltins are more reactive than comparable vinyltins. Hyperconjugation in the transition state of the SE2 reaction is proposed to account for the increased reactivity of the allenyltins. Also, a modified steric sequence is observed when substituents on tin are varied. This is consistent with an open transition state.
