Silylcupration of Allene with the Lower Order Cuprate (<i>t</i>-BuPh<sub>2</sub>Si)CuCNLi and Reaction with α,β-Unsaturated Nitriles. An Unusual Diaddition Process Leading to Disilyl Functionalised Ketones
作者:Francisco Pulido、Asunción Barbero、Yolanda Blanco、Héctor Fernández
DOI:10.1055/s-2004-835643
日期:——
The lower order cuprate (t-BuPh2Si)CuCNLi, prepared by mixing one equivalent of t-butyldiphenylsilyllithium and one equivalent of copper(I) cyanide, reacts with allenes in the presence of α,β-unsaturated nitriles showing a regiochemistry that depends on the electronic nature of the nitrile. Electron-poor nitriles give monoadducts (allylsilane containing nitriles) whereas electron-rich nitriles lead to diadducts (allylsilane-vinylsilane containing ketones), the latter resulting from an unusual diaddition (1,2 and 1,4) process. An explanation is advanced and a reliable mechanism proposed.
低级别铜酸盐(t-BuPh2Si)CuCNLi是通过将一个当量的t-butyldiphenylsilyllithium与一个当量的铜(I)氰化物混合制备的。在α,β-不饱和腈的存在下,与烯丙烯发生反应,其区域化学结构取决于腈的电子性质。电子贫乏的腈生成单加成物(含腈的烯丙基硅烷),而电子丰富的腈则生成双加成物(含酮的烯丙基硅烷-乙烯基硅烷),后者是由一种不寻常的双加成(1,2和1,4)过程导致的。文章提出了一个解释并提出了一个可靠的机制。