DEVELOPMENT OF AN ASYMMETRIC PHOSPHINE-CATALYZED UMPOLUNG-ADDITION REACTION AND ITS APPLICATION TO THE SYNTHESIS OF HPI ALKALOIDS

Abstract

The field of phosphine organocatalysis developed rapidly over the last two decades and chiral phosphine organocatalysts have been utilized in a variety of enantioselective transformations. Among all, umpolung gamma-addition reaction is considered to be one of the most conventional reaction modes. This thesis describes the development of a new umpolung gamma-addition reaction mediated by an amino-acid derived bifunctional phosphine organocatalyst. Briefly, this established approach afforded a variety of chiral mixed 3,3′-bisindoles containing an all-carbon quaternary stereogenic center in high yields and with excellent enantioselectivities. Furthermore, the path which led to the formal total synthesis of (+)-chimonanthine, (+)-folicanthine and (-)-calycanthine as well as studies towards the total synthesis of gliocladin C were discussed in detail.