Synthesis of 2-Alkylidenepyrrolidines and Pyrroles by Condensation of 1,3-Dicarbonyl Dianions with α-Azidoketones and Subsequent Intramolecular Staudinger−Aza-Wittig Reaction

Abstract

The condensation of 1,3-dicarbonyl dianions with alpha-azidoketones afforded open-chained condensation products that were transformed into pyrroles by Staudinger-aza-Wittig reactions and the subsequent treatment with trifluoroacetic acid.

Energetics and Molecular Structure of 2,5-Dimethyl-1-phenylpyrrole and 2,5-Dimethyl-1-(4-nitrophenyl)pyrrole

“…The pyrrole molecule is a fundamental building block for biological systems, such as chlorophyll, hemoglobin, and cytochromes. The pyrrole-containing compounds are used in the synthesis of pharmaceuticals, − dyes, , agrochemicals, and other organic compounds. − They also find technological applications such as catalysts, corrosion inhibitors, battery materials, and pacifying layers for semiconductors…”

Synthesis and Consecutive Reactions of α-Azido Ketones: A Review

“…The pyrrole ring appears in a large number of pharmaceutically active natural compounds and wonder drugs (e.g., zomepirac and atorvastatin). Keeping in view the synthetic utility of pyrroles, the condensation reaction between α-azido ketones and 1,3-dicarbonyl dianions was carried out by Freifeld in 2006 [43]. This reaction procedure resulted in the open chain condensed products that were transformed into pyrroles by Staudinger-Aza-Wittig reactions followed by subsequent treatment with trifluoroacetic acid (TFA).…”

Five‐Membered Heterocycles: Pyrrole and Related Systems

“…The procedure could be applied for the preparation of various pyrrole-2-carboxylates bearing aryl, heteroaryl, and alkyl groups [709]. Likewise, pyrrole derivatives have also been constructed by initial reactions of 1,3-dicarbonyl anions with a-azidoketones, and ensuing annulation of the resulting intermediates employing the Staudingeraza-Wittig reaction [710]. Precursors for similar reductive cyclizations may also be assembled from 1,3-bis-silyl enol ethers and 1-azido-2,2-dimethoxyethane in the presence of TMSOTf [711].…”