Ugi four-component reaction with tandem deprotection, cyclization and pictet-spengler reaction: A concise route to N-fused polycyclic indoledi-ketopiperazine alkaloid analogues

摘要

Aza-fused polycyclic indolediketopiperazine alkaloids are of potential interest due to their broad range of biological activities. Traditionally, a number of methods have been used to generate N-fused polycyclic indolediketopiperazine skeletons, but the need to develop novel, concise methods with which to modify the substitution pattern continues. Herein, we describe the two-step formation of N-fused polycyclic indolediketopiperazine alkaloid analogues by the application of the Ugi four-component reaction with tandem deprotection, cyclization and Pictet-Spengler reaction.