γ-Hydroxy-γ-butyrolactams as 1,2-bis-electrophiles in a Brønsted/Lewis acid-free synthesis of condensed nitrogen heterocycles†
Abstract
Here, we describe the one-pot assembly of imidazo[1,2-a]pyridine and quinoxaline heterocyclic cores by the electrophilic tandem cyclization between 3,5-diaryl substituted 5-hydroxy-3-pyrrolin-2-ones and the corresponding nitrogen bis-nucleophiles. This microwave-assisted annulation occurs in superheated water and does not require the addition of any acid.