Synthesis of Substituted N-Heterocycles via Cascade, Michael Addition, Double Cyclization and Air Oxidation Reaction

Abstract

An efficient synthesis of α-carbolinones (pyridoindolones) and α-carbolines (pyridoindoles) from 2-(2-aminophenyl)acetonitriles and alkyl/arylidene malonates and 2-benzylidene-3-oxopentanoates mediated by Cs2CO3 in excellent yields has been developed. This methodology enables the formation of five-six membered nitrogen heterocyclic compounds via Michael addition, followed by double cyclization, elimination, rearrangement and air oxidation reaction in a cascade fashion. Post-synthetic modification enables the synthesis of pentacyclic nitrogen heterocyclic compounds.