Trofimov Reaction Research Articles

Stereochemical Study of 2-Substituted N-Vinylpyrroles

Stereochemical study of five 2-substituted N-vinylpyrroles obtained via the Trofimov reaction was carried out based on the experimental measurements of their 13C–1H and 13C–13C spin–spin coupling constants substantiated by the high-level ab initio calculations of the parent 2-methyl-N-vinylpyrrole. The title compounds were shown to adopt a predominantly skewed s-trans conformer with a noticeable population (approximately 10%) of the higher-energy skewed s-cis conformation, however, with the exception of 2-tert-butyl-N-vinylpyrrole adopting almost entirely a skewed s-trans conformation.

Dioximes of 1,3‐Diketones in the Trofimov Reaction: New 3‐Substituted Pyrroles.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Synthesis and electrochemical characterization of dipyrroles separated by diphenyleneoxide and diphenylenesulfide spacers via the Trofimov reaction

4,4′-Bis[2-(1-vinylpyrrolyl)]diphenyloxide, 4,4′-bis(2-pyrrolyl)diphenylsulfide, 4-(2-pyrrolyl)-4′-[2-(1-vinylpyrrolyl)]diphenylsulfide and 4,4′-bis[2-(1-vinylpyrrolyl)]diphenylsulfide have been synthesized in a one-pot procedure from oximes of corresponding diacetylphenylenoxide and -sulfide through their reaction with acetylene in the MOH–DMSO systems (M=Li, K) at 80–130 °C under pressure of 10–15 atm, thus illustrating applicability and general character of the reaction of synthesis of diverse dipyrrole–phenylene assemblies and their N-vinyl derivatives. Two of the pipyrroles are promising for creating new conducting polymers with sulfur and oxygen atoms in the conjugation chain and for the study of the influence of the diphenyleneheteroatom moiety on conductivity of final polymer products. For the dipyrroles with the diphenyleneheteroatom moieties and 1,4-phenylene spacer the luminescence characteristics were determined.

Dioximes of 1,3-Diketones in the Trofimov Reaction: New 3-Substituted Pyrroles

Dioximes of 1,3-diketones enter into the Trofimov reaction forming pyrroles containing an acyl or an O-vinyloxime substituent in position 3 of the pyrrole. In the case of sterically hindered dioximes the main reaction products are isoxazoles.

Synthesis of 2-mesityl-3-methylpyrrole via the Trofimov reaction for a new BODIPY with hindered internal rotation

The reaction of E-ethylmesitylketoxime with acetylene in the system KOH/DMSO (the Trofimov reaction) (70–74 °C, 3 h, atmosphere pressure) affords 2-mesityl-3-methylpyrrole (23%), 2-mesityl-3-methyl-1-vinylpyrrole (8%), Z- (5%) and E- (2%) isomers of O-vinylethylmesitylketoxime. Initial ethylmesitylketoxime was prepared in two ways: via very slow oximation of ethylmesitylketone in 30% yield after 8 months, and, more efficiently, by oximation of ethylmesitylketimine hydrochloride derived from bromomesitylene in several steps. 2-Mesityl-3-methylpyrrole was used for the synthesis of 4,4-difluoro-2,6-dimethyl-3,5,8-trimesityl-4-bora-3a,4a-diaza- s-indacene with mesityl substituents having hindered internal rotation and preventing π-stacking at high concentrations. The latter factor enables the fluorescence of crystals of the prepared BODIPY, a feature that was not previously documented for such molecules.

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

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 NH2OH·HCl-NaHCO3 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.

Heterocyclization of Oximes of 3,5‐Dimethyl(1,3,5‐trimethyl)‐2,6‐diphenylpiperid‐4‐ones and N‐Benzylpyrrolid‐3‐ones with Acetylene in a Superbasic Medium.

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A selective synthesis of 2-([2,2]paracyclophan-5-yl)pyrrole from 5-acetyl[2,2]paracyclophane via the Trofimov reaction

Rearrangement of 5-(1-vinyloxyiminoethyl)[2,2]paracyclophane, the key intermediate of the Trofimov reaction (pyrrole formation from ketoximes and acetylene), gives (120°C, 30min, DMSO) 2-([2,2]paracyclophan-5-yl)pyrrole in 74% yield. The intermediate 5-(1-vinyloxyiminoethyl)[2,2]paracyclophane has been synthesised in 78% yield by vinylation of the Cs-derivative of the oxime of 5-acetyl[2,2]paracyclophane with acetylene under pressure in the DMSO–n-pentane two-phase system (70°C, 5min).

Trofimov Reaction with Oximes Derived from Ketosteroids: Steroid—Pyrrole Structures.

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Heterocyclization of Oximes of 3,5-Dimethyl(1,3,5-trimethyl)-2,6-diphenylpiperid-4-ones and N-Benzylpyrrolid-3-ones with Acetylene in a Superbasic Medium

It has been established that on heterocyclization of 3,5-dimethyl-2,6-diphenylpiperid-4-one oxime with acetylene in a superbasic medium migration of the 3a-CH3 group to the anionic nitrogen atom occurs, leading to the formation of 5,7-dimethyl-4,6-diphenyl-4,5,6,7-tetrahydropyrrolo[3,2-c]pyridine. The formation of the N-anion causes aromatization of the tetrahydropyridine ring. Tetrahydropyrrolo[1,2-c]pyrimidines are formed in the Trofimov reaction as a result of decomposition of the intermediate 3H-pyrrole in a retro-Mannich reaction.

Trofimov Reaction with Oximes Derived from Ketosteroids: Steroid-Pyrrole Structures

Steroidal ketone oximes, namely pregnenolone oxime, Δ5-cholesten-3-one oxime, and progesterone dioxime react with acetylene in superbasic systems (Trofimov reaction) to afford steroid-pyrrole assemblies. The process is accompanied by prototropic migration of double bonds in the steroid fragment and vinylation of hydroxy groups in sterols with acetylene. The O-vinyl group can readily be removed by methanolysis.

Anellation of the Pyrrole to the Steroid Skeleton Using the Trofimov Reaction.

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First Example of Construction of a Pyrrole Ring Bonded to a Steroid System by the Trofimov Reaction.

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Annelation of the Pyrrole to the Steroid Skeleton Using the Trofimov Reaction

The product of annelation of the N-vinyl pyrrole ring with steroid skeleton of 5-cholestene was obtained in a single regioselective step by the reaction of 5-cholesten-3-one oxime with acetylene in KOH-DMSO by the Trofimov reaction.

ChemInform Abstract: Unexpected Formation of 1‐Vinyl‐2‐[2′‐(6′‐methylpyridyl)]pyrrole (III) from Dimethylglyoxime and Acetylene in the Trofimov Reaction.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

First Example of Construction of a Pyrrole Ring Bonded to a Steroid System by the Trofimov Reaction

The oxime of Δ5-pregnen-3β-ol-20-one reacts with acetylene in the KOH-DMSO system to form a mixture of products containing 3β-vinyloxy-17β-(1-vinyl-2-pyrrolyl)-Δ5-androstene as the major product (63% yield) and also the O-vinyloxime of 3β-vinyloxy-Δ5-pregnen-20-one (10%), 3β-vinyloxy-17α- and 3β-vinyloxy-17β-Δ5-pregnen-20-one (25%, 1:4 ratio).

Unexpected formation of 1-vinyl-2-[2′-(6′-methylpyridyl)]pyrrole from dimethylglyoxime and acetylene in the Trofimov reaction

Dimethylglyoxime reacts with acetylene under pressure in the KOH–DMSO system to give 1-vinyl-2-[2′-(6′-methylpyridyl)]- pyrrole along with the expected products of the Trofimov reaction (O-vinyloxime, pyrrole and dipyrrole).

ChemInform Abstract: Synthesis of 1H‐ and 1‐Vinyl‐2‐pyridylpyrroles by the Trofimov Reaction.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis of 1 H- and 1-vinyl-2-pyridylpyrroles by the Trofimov reaction

A one-pot synthesis of 2-(2-pyridyl)-1H-pyrrole and 1-vinyl-2-(2-pyridyl)-, 1-vinyl-2-(3-pyridyl)- and 1-vinyl-2-(4-pyridyl)-pyrroles from oximes of 2-acetyl-, 3-acetyl- and 4-acetylpyridine and acetylene under pressure (16-25 atm) in a KOH/DMSO system has been carried out (105-120 °C, 3 h) to reveal for the first time the applicability of the Trofimov reaction for the preparation of alkaloids of the nicotine series.

ChemInform Abstract: Electrophilic Rearrangement of N‐H‐Tetrahydro‐3H‐pyrrolo(3,2‐c) pyridine to N‐Methyltetrahydropyrrolo(3,2‐c)pyridine under Conditions of the Trofimov Reaction.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.