Microwave-Assisted Construction of Pyrrolopyridinone Ring Systems by Using an Ugi/Indole Cyclization Reaction.

A series of pyrrolopyridinones were prepared by using N-Boc-pyrrole-2-carbaldehyde as a starting material in an Ugi reaction followed by an acid-mediated indole cyclization to result in the formation of a new C-C bond. Changes to the other starting materials in this Ugi/indole cyclization reaction sequence extended the scope of this method to include a nucleophilic substitution reaction and an Ugi/deprotection/cyclization (UDC) strategy, which provided access to two new series of heterocyclic compounds. This method represents a facile and efficient one-pot procedure for the preparation of pyrrolopyridinones under acidic conditions. [ABSTRACT FROM AUTHOR]