Barbero Asunción, Blanco Yolanda, Pulido Francisco J
Departamento de Química Orgánica, Universidad de Valladolid, 47011 Valladolid, Spain.
J Org Chem. 2005 Aug 19;70(17):6876-83. doi: 10.1021/jo0509814.
The silylcupration of allenes and the subsequent capture of the intermediate cuprate with alpha,beta-unsaturated nitriles is reported. The influence of the substitution of the nitrile, the nature of the silylcopper species, and the temperature on the selectivity of the reaction is studied. An interesting diaddition process was observed (1,2-addition and 1,4-addition), leading to oxo compounds which simultaneously have an allylsilane and a vinylsilane group. The different reactivity of these two units has been employed in the intramolecular allylsilane-terminated cyclization of these adducts, where the vinylsilane moiety remains unchanged. To shed some light on the reaction pathway, the behavior of alpha,beta-unsaturatedd imines was also checked and a new and convenient way for cycloheptane annulation presented. In light of the former results a feasible mechanism is proposed.
报道了丙二烯的硅基铜化反应以及随后用α,β-不饱和腈捕获中间体铜酸盐的反应。研究了腈的取代基、硅基铜物种的性质和温度对反应选择性的影响。观察到一个有趣 的双加成过程（1,2-加成和1,4-加成），生成了同时含有烯丙基硅烷和乙烯基硅烷基团的氧代化合物。这两个单元的不同反应活性已被用于这些加合物的分子内烯丙基硅烷终止的环化反应中，其中乙烯基硅烷部分保持不变。为了阐明反应途径，还研究了α,β-不饱和二亚胺的行为，并提出了一种新的、方便的环庚烷环化方法。根据之前的结果，提出了一个可行的机理。
