A Versatile Total Synthesis of Benzo[<i>c</i>]phenanthridine and Protoberberine Alkaloids Using Lithiated Toluamide−Benzonitrile Cycloaddition
作者:Thanh Nguyen Le、Seong Gyoung Gang、Won-Jea Cho
DOI:10.1021/jo035836+
日期:2004.4.1
A new versatile synthesis of benzo[c]phenanthridine and protoberberine alkaloids using lithiated toluamide−benzonitrile cycloaddition was carried out. The coupling reaction between benzonitrile 6 with o-toluamides (8a−c) afforded 3-arylisoquinolines (9a−c) that were transformed to the protoberberines (11a−c) or benzo[c]phenanthridines (14a−c). These compounds were synthesized by ring closure of the
利用锂化的甲苯胺-苄腈环加成法进行了苯并[ c ]菲啶和原小ber碱生物碱的新型通用合成。苄腈6与邻甲苯甲酰胺(8a - c)之间的偶联反应提供了3-芳基异喹啉(9a - c),该3-芳基异喹啉(9a - c)转化为原小ber碱(11a - c)或苯并[ c ]菲啶(14a - c)。这些化合物是通过在3-芳基异喹啉酮(9a - c)。合成了几种取代的苯并[ c ]菲啶生物碱,例如氧山桂碱,氧鸟嘌呤和氧可尼丁,以及原小ber碱,例如8-氧代黄嘌呤,8-氧代伪小ber碱和8-氧代葡多酚。