Oxidized isoquinolinoisoindolinone and benzazepinoisoindolinone alkaloids cores by convergent cyclisation processes: π-aromatic attack of thionium and oxonium species
作者:Till Bousquet、Jean-François Fleury、Adam Daïch、Pierre Netchitaïlo
DOI:10.1016/j.tet.2005.10.017
日期:2006.1
An efficient methodology for synthesis of isoindoloisoquinoline 5a and isoindolobenzazepine 5b in oxidized forms as tetracyclic alkaloids cores are reported from N-bromoethylphthalimide (6) or phthalic anhydride and 2-phenylthioethylamine (8) in a five- or six-step sequence, respectively, in overall very good yields. The key step of this methodology is based on an intramolecular π-cationic cyclization
从N-溴乙基邻苯二甲酰亚胺(6)或邻苯二甲酸酐和2-苯基硫代乙胺(8)分别以五步或六步顺序报告了一种有效的方法,该方法可以合成氧化形式的四环生物碱核心形式的异吲哚异喹啉5a和异吲哚并苯并ze庚因5b。总体产量非常好。该方法的关键步骤是基于硫鎓离子种类的分子内π-阳离子环化。备选地,探索了另外的四步路线,并且该路线的最后一步是基于醛官能团的环脱水作用,醛官能团通过氧鎓离子阳离子在最新策略中用作中间体。