A straightforward synthesis of pyrroles from ketones and acetylene: a one-pot version of the Trofimov reaction

Abstract

Alkyl-, aryl-and hetaryl ketones after a one-pot oximation and treatment with acetylene are converted to 2-mono-and 2,3-disubstituted NH-and N-vinylpyrroles with alkyl-, aryl-and hetaryl substituents in good yields. The oximation is effected using a NH 2 OH·HCl-NaHCO 3 system at room temperature. The reaction with acetylene is carried out in the presence of the KOH/DMSO superbase at 100 o C under atmospheric pressure.

Influence of the Introduction of Short Alkyl Chains in Poly(2-(2-Thienyl)-1H-pyrrole) on Its Electrochromic Behavior

“…Also the one-pot three-component version of this reaction (Scheme ) starting directly from ketones, hydroxylamine and acetylene in the KOH/DMSO system elaborated recently has been significantly modified. , …”

Exploring the influence of steric hindrance and electronic nature of substituents in the supramolecular arrangements of 5-(substituted phenyl)-2-formylpyrroles

“…17 However, only a few examples in the literature reported their synthesis, and often just for the simplest aryl derivative, 5-phenyl-2-formylpyrrole. 18 The more general synthetic methods described for 5-aryl-2-formylpyrroles include two-step procedures, [19][20][21] with the most efficient method involving the one-step catalytic regioselective C 5 direct arylation of N-substituted 2-formylpyrroles with aryl bromides. 22 Nevertheless, the final products are usually N-substituted 5-aryl-2-formylpyrroles and not the corresponding NH-analogues.…”

Synthesis of 2-Formylpyrroles from Pyridinium Iodide Salts

“…So far, numerous efficient methodologies have been developed for the synthesis of 2-formylpyrroles. The conventional methods rely on the Vilsmeier–Haack formylation of the preformed parent pyrrole, which is usually synthesized by Hantzsch, Knorr, Paal–Knorr, Barton–Zard, and Trofimov reactions . A sustainable Maillard approach to 2-formylpyrroles from primary amines and sugar was described by Fujimaki, Zhao, Koo, and others .…”

“…The conventional methods rely on the Vilsmeier−Haack formylation of the preformed parent pyrrole, 8 which is usually synthesized by Hantzsch, 9 Knorr, 10 Paal−Knorr, 11 Barton−Zard, 12 and Trofimov reactions. 13 A sustainable Maillard approach to 2formylpyrroles from primary amines and sugar was described by Fujimaki, Zhao, Koo, and others. 14 Padwa and coworkers constructed the 6-phenyl-2-formylpyrrole from 2H-azirine by treating with Grubb's catalyst.…”