Three-component solvent-free synthesis of highly substituted bicyclic pyridines containing a ring-junction nitrogenElectronic supplementary information (ESI) available: General procedures and spectroscopic data, including copies of 1H and 13C NMR spectra. CCDC reference number 784140. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c0gc00373e

An efficient one-pot, three-component synthesis of highly substituted bicyclic pyridines containing a ring-junction nitrogen, starting from simple and readily available materials, is described. Cyclocondensation of heterocyclic ketene aminals (HKAs), triethoxymethane, and active methylene compounds by refluxing under solvent-free and catalyst-free conditions, provided bicyclic pyridines in excellent yields. [ABSTRACT FROM AUTHOR]