New Polymer-Supported Mono- and Bis-<i>Cinchona</i>Alkaloid Derivatives: Synthesis and Use in Asymmetric Organocatalyzed Reactions
作者:Ravindra P. Jumde、Anila Di Pietro、Antonella Manariti、Alessandro Mandoli
DOI:10.1002/asia.201402924
日期:2015.2
Chinchona alkaloids and their application in the asymmetric dimerization of ketenes is reported. Six different immobilized derivatives, consisting of three dimeric and two monomeric 9‐O ethers, were prepared by “click” anchoring of soluble alkaloid precursors on to azidomethyl resins. The resulting insoluble polymer‐bound (IPB) organocatalysts were employed for promoting the dimerization of in‐situ
聚苯乙烯负载的简单的合成金鸡报道生物碱和它们在烯酮的二聚化非对称应用。通过将可溶性生物碱前体“点击”固定在叠氮甲基树脂上,制备了由三种二聚体和两种单体9- O醚组成的六种不同的固定化衍生物。所得的不溶性聚合物结合(IPB)有机催化剂用于促进原位生成的烯酮的二聚作用。用N,O-二甲基羟胺打开烯酮二聚体中间体后,最终获得了有价值的Weinreb酰胺,收率很高(高达81%),对映体纯度也很高(ee高达96%))。所有IPB催化剂都可以有效地回收利用,而不会显着降低活性和对映选择性。还简要讨论了对其他不对称转变的扩展(内消旋酸酐的不对称化和2-氧吲哚的α-胺化)。