Synthesis and practical applications of 2-(2-nitroalkyl)pyrroles

Abstract

Two main approaches can be designed for the synthesis of 2-(2-nitroalkyl)pyrroles using nitroalkenes or nitroalkanes in the reaction with pyrrole derivatives. The obtained nitroalkyl pyrroles can be converted into various bioactive compounds.

Synthesis of bacteriochlorins bearing diverse β-substituents

“…While 1 H NMR spectroscopic analysis routinely affords a characteristic ABX pattern of the methylene protons on the carbon adjacent to the stereogenic center, structural analysis of such pyrrole-nitrohexanones has previously been reported for only four compounds, [46][47][48] although compounds containing the 2-(2-nitroethyl)pyrrole moiety are growing in importance. 49 To our surprise, the standard self-condensation conditions 15 afforded 5-unsubstituted BC-1 only in 4.1% yield and was accompanied by 5-methoxybacteriochlorin BC-2 in 1.7% yield. While the origin of the low yield of self-condensation of 13 (compared to other dihydrodipyrrins bearing electronwithdrawing groups 16 ) is unclear, this route was employed to obtain B25 mg of the desired bacteriochlorin BC-1.…”

“…While 1 H NMR spectroscopic analysis routinely affords a characteristic ABX pattern of the methylene protons on the carbon adjacent to the stereogenic center, structural analysis of such pyrrole–nitrohexanones has previously been reported for only four compounds, 46–48 although compounds containing the 2-(2-nitroethyl)pyrrole moiety are growing in importance. 49…”

An Easy Synthesis of Monofluorinated Derivatives of Pyrroles from β-Fluoro-β-Nitrostyrenes

“…Indeed, the introduction of a 2-Nitroalkyl moiety into the pyrrole nucleus has attracted much research interest. 2-(2-Nitroalkyl)pyrroles were demonstrated to be appealing intermediates for the synthesis of bioactive compounds [14].…”

NHC-catalyzed [3 + 3] cycloaddition of α-bromoenals with nitroketene aminals or nitroketene N,S-acetals: synthesis of nitro-containing dihydropyridin-2-ones

“…4 On the other hand, due to the highly electron-withdrawing nature of the nitro group, simple nitro-containing molecules can serve as valuable synthetic intermediates in the synthesis of complex molecules. 5 Despite the tremendous advancements in this field, efficient construction of nitro-containing heterocyclic compounds from readily available starting materials under mild conditions is still highly desirable.…”