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.
Key words
alkaloids - Ugi reaction - tandem reactions - deprotection - cyclization - Pictet–Spengler
reaction