ChemInform Abstract: Heterocycles from α‐Nitroolefins. Part 12. 3‐Acetyl‐4,5‐dihydro‐5‐(methylenamino)furans and 3‐Acylpyrroles from α‐Nitroolefins and β‐Diketones.

Abstract

166ChemInform Abstract The α-nitroolefins (I) react with the 1,3-diketones (II) in the presence of bases, yielding the dihydrofurans (IV). These are cleaved by hydrolysis to form the 3-acylpyrroles (V) and the triones (VI). Hydrogenolysis of (IV) produces the N-substituted pyrroles (VII). (IR-, 1H-NMR-, MS-data).

One‐pot three‐component synthesis of tetrasubstituted N—H pyrroles from secondary propargylic alcohols, 1,3‐dicarbonyl compounds and tert‐butyl carbamate

“…THF (0.5 mL), complex 1 (0.049 g, 0.05 mmol), and TFA (37 μL, 0.5 mmol) were then added at room temperature, and the resulting solution was heated at 75°C for 24 h. After elimination of the solvent under reduced pressure, the crude reaction mixture was purified by column chromatography over silica gel using an ethyl acetate/hexane mixture (1:10 v/v) as eluent. 1 H and 13 C{ 1 H} NMR spectra, as well as melting points, obtained for compounds 3a [9], 3b [16], 3d [8], 3e [9], 4a [16], 4c [16], 5a [17], and 5b [18] were in complete accord with those described in the literature. Characterization data for the novel pyrroles 3c and 4b , d are as follows:…”