A New Modular Indole Synthesis. Construction of the Highly Strained CDEF Parent Tetracycle of Nodulisporic Acids A and B

Construction of the highly strained CDEF parent tetracycle, a structural motif found only in the potent ectoparasiticidal agents (+)-nodulisporic
acids A and B and related congeners, has been achieved via a new modular indole synthesis, exploiting a sequential Stille cross-coupling/Buchwald−Hartwig union/cyclization tactic. The new indole synthesis holds the promise of rapid assembly of diverse, highly substituted
indoles possessing uncommon substitution patterns.

高度应变的CDEF母四环（一种仅在强效外寄生虫杀虫剂（+）-nodulisporic酸A和B及其相关同系物中发现的构象基元）的构建，已通过一种新型的模块化吲哚合成方法实现，该方法利用了Stille交叉偶联/ Buchwald-Hartwig偶联/环化策略的顺序操作。这种新的吲哚合成方法预示着能够迅速组装出具有多种不同取代模式和高度取代的吲哚。