Assembly of the Bis(imidazolyl)propene Core of Nagelamides C and S by Double Grignard Reaction
作者:Nicolas Jacobi、Thomas Lindel
DOI:10.1002/ejoc.201000625
日期:——
1-bis(imidazolyl)-propenes were assembled in a facile manner by double Grignard reaction of metalated imidazoles with saturated esters, followed by dehydration. The presence of nitrile functions or acryl esters in the electrophile component leads to competing reactions, whereas propargyl esters are tolerated. Introduction of 2-amino groups was possible via the corresponding dimethylsulfamoyl-protected
作为几种非单体吡咯-咪唑生物碱的特征结构元素,1,1-双(咪唑基)-丙烯通过金属化咪唑与饱和酯的双重格氏反应,然后脱水以简便的方式组装。亲电子试剂组分中腈官能团或丙烯酸酯的存在会导致竞争反应,而炔丙酯是可以容忍的。可以通过相应的二甲基氨磺酰基保护的 2-叠氮基咪唑引入 2-氨基,其在氢化之前必须脱保护。基于 NOESY 的分析揭示了咪唑 5 位朝向丙烯基链的优先取向。