Suzuki–Miyaura cross-coupling, followed by a regioselective reduction employing LiDBB. Starting from 6-iodoindole, the sequence needs nine steps and provided (±)-raputindole A in 6.6% overall yield. The absolute configuration of the natural product (+)-raputindole A was determined by quantum chemical calculation of the ECD spectrum.
据报道,从芸苔植物Raputia simulans中首次合成了双
吲哚生物碱RaputindoleA 。关键步骤是Au(I)催化的环化反应,该反应由6烷基化的
吲哚啉前体组装成环戊[ f ]
吲哚三环。
异丁烯基侧链通过Suzuki-Miyaura交叉偶联安装,然后使用Li
DBB进行区域选择性还原。从6-
碘吲哚开始,该序列需要九个步骤,并以6.6%的总收率提供了(±)-raputindoleA。
天然产物(+)-raputindole A的绝对构型是通过
ECD光谱的量子
化学计算确定的。