NMR Studies of Five-Coordinate Tin Enolate: An Efficient Reagent for Halo Selective Reaction toward. alpha.-Halo Ketone or. alpha.-Halo Imine

…, I Shibata, A Baba, H Matsuda, N Sonoda

Index: Yasuda, Makoto; Katoh, Yasuhiro; Shibata, Ikuya; Baba, Akio; Matsuda, Haruo; Sonoda, Noboru Journal of Organic Chemistry, 1994 , vol. 59, # 16 p. 4386 - 4392

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Citation Number: 47

Abstract

NMR studies of tin enolates 1, in the presence of HMPA, revealed the presence of a five- coordinate 0-stannyl enolate l (h) which contributes to upfield shifts of Sn peaks in the llsSn NMR spectrum and increased coupling constants J (l19Sn-13C), compared with the four- coordinate tin enolate l (e). The tautomeric equilibrium between C-stannyl ketone l (k) and 0- stannyl enolate l (e) was changed by the addition of HMPA, the percentage of enol form ...