Synthesis of 4‑Substituted 3,5-Dinitro-1,4-dihydropyridines by the Self-Condensation of β‑Formyl-β-nitroenamine
journal contributionposted on 07.03.2014, 00:00 by Yumi Nakaike, Nagatoshi Nishiwaki, Masahiro Ariga, Yoshito Tobe
3,5-Dinitro-1,4-dihydropyridines (DNDHPs) are readily constructed by the acid-promoted self-condensation of β-formyl-β-nitroenamines. In the DNDHPs, one molecule of the nitroenamine serves as a C3N1 building block and the other serves as a C2 block. This synthetic method does not require any special reagents and conditions. When the reaction is conducted in the presence of electron-rich benzene derivatives, arylation at the 4-position of DNDHP is achieved by trapping the 3,5-dinitropyridinium ion intermediate.