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母四环结构基元，该基元仅存在于强大的外寄生虫杀虫剂（+）-nodulisporic酸A和B及其相关同系物中，已通过一种新型模块化吲哚合成法成功构建。该合成法利用了Stille交叉偶联/Buchwald-Hartwig偶联/环化策略的顺序执行。这一新的吲哚合成法预示着能够快速组装出多种具有非常规取代模式的、高度取代的吲哚。