Novel Redox-Active Cyclophanes Based on 3,3‘-Biindolizines: Synthesis and Chirality
作者:Helmut Sonnenschein、Thomas Kreher、Egon Gründemann、Ralph-Peter Krüger、Annamarie Kunath、Volker Zabel
DOI:10.1021/jo951419o
日期:1996.1.1
dehydrocyclization of bridged indolizines of type 1. The bridged dipyridino-compounds 2a and 2b obtained by reaction of 2 mol of lithiated alpha-picolines with dihalides were used as starting materials. Subsequent treatment of 2a,b with 2 mol of alpha-bromo ketones gave quaternary pyridinium halides. Ring closure in an alkaline medium (Chichibabin reaction) yielded the starting material for the synthesis of the macrocycles
通过对1型桥连吲哚嗪进行脱氢环化反应,制备了一系列新的氧化还原活性环烷的首批化合物。以2 mol锂化α-甲基吡啶与二卤化物反应制得的桥联双吡啶化合物2a和2b为起始原料。随后用2mol的α-溴代酮处理2a,b,得到季吡啶鎓卤化物。在碱性介质中闭环(Chichibabin反应)产生了合成大环化合物的原料。氧化CC偶合得到3型非对映体环烷。在所有情况下,过量获得一对对映体。简历研究表明,主要产品是可逆氧化还原系统。为了阐明它们的构象,对化合物3c,3d / 1和3d / 2进行X射线分析。