Novel (2-amino-4-arylimidazolyl)propanoic acids and pyrrolo[1,2-c]imidazoles via the domino reactions of 2-amino-4-arylimidazoles with carbonyl and methylene active compounds

• Victoria V. Lipson,
• Tetiana L. Pavlovska,
• Nataliya V. Svetlichnaya,
• Anna A. Poryvai,
• Nikolay Yu. Gorobets,
• Erik V. Van der Eycken,
• Irina S. Konovalova,
• Svetlana V. Shiskina,
• Alexander V. Borisov,
• Vladimir I. Musatov and
• Alexander V. Mazepa

Beilstein J. Org. Chem. 2019, 15, 1032–1045, doi:10.3762/bjoc.15.101

• ]. Oroidine (V) and other related vinyl 2-aminoimidazoles of this class are monomeric precursors of nagelamide A (VII), mauritiamine (VIII), sceptrin (IX), benzosceptrin A (X), axinellamines (XI) and stylissazole A (XII) alkaloids [1][4][5]. Fused 2-aminoimidazole and azepinone derivatives XIII were isolated

The marine sponge Agelas citrina as a source of the new pyrrole–imidazole alkaloids citrinamines A–D and N-methylagelongine

• Christine Cychon,
• Ellen Lichte and
• Matthias Köck

Beilstein J. Org. Chem. 2015, 11, 2029–2037, doi:10.3762/bjoc.11.220

• alkaloids (PIAs), the citrinamines A–D (1–4) and the bromopyrrole alkaloid N-methylagelongine (5). All citrinamines are dimers of hymenidin (6) which was also isolated from this sponge as the major metabolite. Citrinamines A (1) and B (2) are derivatives of the PIA dimer mauritiamine (7), whereas

• ) which consist of a pyridinium ring and an ester linkage instead of the aminoimidazole moiety and the common amide bond in PIAs. Keywords: Agelas citrina; marine sponges; mauritiamine; NMR; pyrrole–imidazole alkaloids; Introduction The family of pyrrole-imidazole alkaloids (PIAs) represents a

• . The structure of 1 is very similar to mauritiamine (7) [12] and its 2´-debromo derivative nagelamide P (18) [13]. The 1D and 2D 1H and 13C NMR spectra of 1 showed two additional signals for sp2 methines indicating two 3-bromopyrrole carboxamide moieties (Table 1). The similarities of the NMR data of 1