Construction of 3,5-dinitrated 1,4-dihydropyridines modifiable at 1,4-positions by a reaction of β-formyl-β-nitroenamines with aldehydesElectronic supplementary information (ESI) available: Copies of 1H and 13C NMR spectra for new compounds, the details about optimization of reaction conditions, and X-ray crystallographic data (CIF file), ORTEP drawing for 3ab. CCDC 1416840. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5ra19439c

A novel and efficient method for the synthesis of 4-substituted 3,5-dinitro-1,4-dihydropyridines by a reaction of β-formyl-β-nitroenamines with aldehydes was developed. The reaction of nitroenamines with aldehydes leading to 1,4-dihydropyridines and the self-condensation of nitroenamines leading to pyridinium salt intermediate proceed competitively. The obtained 3,4,5-trisubstituted-1,4-dihydropyridines readily transformed into the corresponding pyridines in high yields. A novel and efficient method for the synthesis of 4-substituted 3,5-dinitro-1,4-dihydropyridines by a reaction of β-formyl-β-nitroenamines with aldehydes was developed.