Recent Access to Polycycles via Post-Ugi Reactions
Xiao Tang, Liangliang Song
Abstract
Ugi reactions have been widely studied due to their mild reaction conditions, high structural variability, and wide applications. Ugi adducts have proved to be highly efficient for different kinds of post-transformations by carefully choosing the starting four components. Considering the importance of polycycles, diverse post-Ugi transformations have been employed for the construction of structurally novel polycyclic N-heterocycles. This minireview summarizes the recent developments of post-Ugi reactions for the synthesis of polycycles after the year 2019. Through transition metal catalysis from gold, rhodium, silver, copper, and palladium, as well as transition metal-free approaches, versatile polycycles are constructed in a highly efficient and step-economical manner.