Calothrixins AとBの全合成

抄録

We have demonstrated a new approach to synthesizing calothrixins A and B through the palladium-catalyzed tandem cyclization/cross-coupling reaction of indolylborate by taking advantage of the one-pot generation of the hexatrienes as a key intermediate for constructing indolophenanthridine. In addition, the unprecedented use of CuOTf for 6π-electrocyclization of hexatriene was developed. In another key transformation, indolophenanthridine quinone core of calothrixins was prepared from the indolophenanthridine aldehyde via one-pot Dakin oxidation sequence catalyzed by diphenyldiselenide.