A dimethylsulfonium methylide mediated highly regioselective olefination of conjugated polyolefin 1,1-dioates to conjugated polyene-2-yl-malonates and their applications in Diels–Alder reactions
作者:Rekha Singh、Sunil K. Ghosh
DOI:10.1016/j.tet.2010.02.013
日期:2010.3
dienophile generation led to quick assembly of precursors for type 2 intramolecular Diels–Alder reaction. Syntheses of functionalized bicyclo[n.3.1] alkenes (n=5 or 6) with the double bond at the bridgehead position have been achieved via the IMDA. An asymmetric version of this reaction has been developed using a MacMillan's imidazolidinone catalyst, which provided a bicyclo[5.3.1] alkene with very
在特定条件下,二甲基s甲基化物与1,3-二烯-或1,3,5-三烯-1,1-二酸酯之间的反应可实现高度区域选择性的串联内酯加成-消除烯烃化反应,从而提供1,3-丁二烯-2-基-或1,3,5-己三烯-2-基丙二酸酯。1,3-丁二烯-2-基丙二酸在丙二酸次甲基碳上的烷基化与合适的具有内置功能的烷基卤化物可用于生成亲二烯体,可快速组装用于2型分子内Diels-Alder反应的前体。官能化的双环[ n .3.1]烯烃的合成(n= 5或6)通过IMDA实现了在桥头位置的双键连接。该反应的不对称形式是使用MacMillan的咪唑烷酮催化剂开发的,该催化剂可提供具有很高对映选择性的双环[5.3.1]烯烃。1,3,5-己三烯-2-基丙二酸在丙二酸次甲基碳上进行原位甲基化,然后与N-甲基马来酰亚胺进行分子间Diels-Alder反应,为环加合物提供了完全的区域控制和非对映选择性。