Iodine-Catalysed Synthesis of β-Carboline Tethered α-Amino Amidines Through Ugi-Type Multicomponent Reaction

摘要

A simple and efficient iodine catalysed protocol has been unfolded for the synthesis of novel β-carboline C1-linked α-amino amidines via one-pot assembly of 1-formyl β-carbolines (Kumujian C analogues), anilines and isocyanides. This domino strategy proceeds through the formation of three C-N bonds in a single operation. The advantageous features of the developed methodology include one-pot synthesis, operational simplicity, high atom economy, broad substrate scope, multi-component character, easy purification procedure (no column chromatography) and applicability towards gram scale synthesis. The scope of strategy has been demonstrated with the construction of a library of 32 novel β-carboline tethered α-amino amidines having three points of diversity.