Enantioselective intramolecular Pictet-Spengler type annulation of indole-linked 3-methyleneisoindolin-1-ones

An enantioselective intramolecular Pictet-Spengler type annulation of indole-linked 3-methyleneisoindolin-1-ones was developed by using a chiral phosphoric acid as a catalyst. This method enabled the construction of a series of chiral isoindolinone fused tetrahydro beta-carbolines in moderate to good yields (up to 97%) with moderate to good enantioselectivities (up to 96% ee). Furthermore, an alpha(1)-AR antagonist was prepared by the reduction of one product. Thus a convenient procedure was provided to construct bioactive tetrahydro beta-carbolines.

Automated summary

A chiral phosphoric acid-catalyzed enantioselective intramolecular Pictet-Spengler type annulation was developed for the synthesis of a series of chiral isoindolinone fused tetrahydro beta-carbolines, which exhibited moderate to good yields (up to 97%) and moderate to good enantioselectivities (up to 96% ee). An alpha(1)-AR antagonist was prepared by reducing one of the products, providing a convenient procedure for constructing biologically active tetrahydro beta-carbolines.