Base‐Mediated Four‐Component Intramolecular Cyclization reaction: One‐pot Access to Imidazole‐4‐(2H)‐ones

Advanced Synthesis & Catalysis, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 22, 2025

Abstract A base‐mediated one‐pot, two‐step, four‐component reaction has been developed to synthesize imidazole‐4(2 H )‐ones, utilizing commercially available amino acid esters, aldehydes, alkynes, and alcohols. Control experiments isolation of the intermediate revealed mechanistic details. This proceeds via imine formation, followed by nucleophilic addition alkyne form a propargylamine precursor. Subsequently, precursor under undergoes conversion into 1‐azadiene, in situ ketene formation generate (allylideneamino)prop‐1‐en‐1‐one. The alcohol subsequent intramolecular cyclization provides imidazole‐4 (2 )‐ones exclusively.

Language: Английский

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A Direct Synthesis of Substituted Exocyclic 1H‐pyrrol‐3(2H)‐ones by Base‐Mediated Multicomponent [3+2] Cycloaddition

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 366(3), P. 473 - 479

Published: Dec. 14, 2023

Abstract A one‐pot, three‐component, base‐mediated [3+2] cycloaddition reaction to synthesize 1 H ‐pyrrol‐3(2 )‐ones from readily available amino acid esters, aldehydes, and terminal alkynes was reported. Isolation of the intermediate detailed mechanistic study revealed course reaction. This multi‐component proceeds via imine formation followed by nucleophilic addition alkyne form a propargylamine precursor. Base‐mediated conversion precursor into 1‐azadiene in situ ketene leading that ultimately produces unusual )‐ones.

Language: Английский

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А Quantum‐Chemical Study of the Mechanism of 1‐Azadienes Formation from Aldimines and Arylacetylenes in the KOtBu/DMSO Superbasic Medium

Asian Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 14, 2024

Abstract The mechanism of 1‐azadienes formation from aldimines and arylacetylenes in the KO t Bu/DMSO superbasic medium has been explored theoretically using a DFT approach [B2PLYP(D2)/6‐311+G(d,p)//B3LYP/6‐31+G(d)] sophisticated model taking potassium tert ‐butoxide nearest solvation shell cation explicitly into account. main focus is placed on (i) detailed analysis kinetic thermodynamic characteristics isomerization intermediate propargylamine 1‐azadienes, (ii) factors determining isomeric composition with different substituents starting arylaldimines arylacetylenes. Our findings clearly indicate that mild experimental conditions are accounted for by relatively small activation barrier (Δ G ≠ ≤16.2 kcal/mol) limiting step (ethynylation aldimine arylacetylenes). rapid to 1‐azadiene found be due low barriers ≤9.1 related protons transfer. case various substituted determined solely difference stability 1 E ,2 ‐ Z ‐forms.

Language: Английский

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A [4+2] Annulation Strategy towards Highly Functionalized 2-Pyridones

Synfacts, Journal Year: 2023, Volume and Issue: 20(01), P. 0095 - 0095

Published: Dec. 8, 2023

Language: Английский

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