Reactions of N-Phosphorylated Aziridines with Dianions Derived from Ethyl Acetoacetate and 1,3-Diketones: New Route to Substituted Pyrrolines and Pyrrolidines

Osowska-Pacewicka, Krystyna; Zwierzak, A.

doi:10.1080/00397919808005953

Cited by 11 publications

(14 citation statements)

References 8 publications

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“…Finally, the ring-opening of N-(diethoxyphosphoryl)aziridines 64 by the dianion derived from ethyl acetoacetate has been described (Scheme 11, B). 71 According to the authors, the reaction proceeds via transient formation of ketoacid 65, which tautomerizes into enol 66 and then undergoes a subsequent cyclization. The last stage can be considered as intramolecular enamine formation with the amidic nitrogen atom acting as an amine equivalent.…”

Section: Scheme 11 Intramolecular Cyclization Of Phosphoramidatesmentioning

confidence: 99%

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N-Phosphorylated Pyrrolidines: An Overview of Synthetic Approaches

et al. 2020

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Organophosphorus pyrrolidine derivatives possessing P–N bonds are a promising yet underexplored class of compounds. In this short review we overview the general approaches to these compounds described so far, with a special emphasis on their asymmetric synthesis.1 Introduction2 Synthesis of Pyrrolidine-Based P(III) Derivatives3 Synthesis of Pyrrolidine-Based P(V) Derivatives3.1 Phosphorylation of Pyrrolidines with P(V) Acid Chlorides3.2 Phosphorylation of Pyrrolidines with P(V) Acid Esters3.3 Syntheses via the Atherton–Todd Reaction3.4 Oxidation of Pyrrolidine-Based P(III) Derivatives4 Syntheses of N-Phosphorylpyrrolidines from Acyclic Precursors5 Conclusions

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Section: Scheme 11 Intramolecular Cyclization Of Phosphoramidatesmentioning

confidence: 99%

“…The final products, (2-ylidenepyrrolidin-1-yl)phosphonates 67, were obtained in high yields; however, no data on the E/Z isomer ratios was given by the authors. 71…”

Section: Scheme 11 Intramolecular Cyclization Of Phosphoramidatesmentioning

confidence: 99%

N-Phosphorylated Pyrrolidines: An Overview of Synthetic Approaches

et al. 2020

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“…Several reviews have covered the preparation and reactivity of these systems; their use is commonplace in total synthesis and methodology as a reliable tool when three-, four-, or five-carbon-chain extension is required. Alkylation reactions of mono- [4][5][6][7][8] and dienediolates 2,9,10 of β-dicarbonyl compounds with alkyl halides continue to be attractive pathways to substituted ketoesters and diketones as well as novel oxygen- 11,12 and nitrogen-containing 12,13 heterocycles. Epoxides have also been used extensively as alkylating reagents for β-dicarbonyl dianions.…”

Section: Introductionmentioning

confidence: 99%

“…Finally, 1 H and 13 C NMR studies in THF-d 8 and DMSO-d 6 provide structural details of the neutral and anionic species derived from 1-3.…”

Section: Introductionmentioning

confidence: 99%

Ion Pair First and Second Acidities of Some β-Diketones and Aggregation of Their Lithium and Cesium Enediolates in THF

Facchetti

Streitwieser

2004

J. Org. Chem.

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Ion pair pK values were measured for three beta-diketones in THF, 1-3, with lithium and cesium counterions. The results showed variations with concentration indicative of aggregation of the metal enolates to dimers. Similarly, ion pair pK values could be determined for some of these metal enolates going to the corresponding dimetal dienediolates which were also found to form dimers. These equilibria are more complicated to analyze because aggregation affects both sides of the proton transfer equilibria. The results show that all of the species measured exist mostly as dimers at concentrations >0.01 M typical of most organic synthesis reactions and physical measurements. NMR measurements show that the enols of 1 and 2, which can undergo intramolecular hydrogen bonding, predominate in both THF and DMSO solutions, whereas 3, whose enols cannot be so stabilized, is mostly keto in THF but approximately equimolar enol and keto in DMSO. Dimerization of the monolithium salts is rapid on the NMR time scale but that of the dilithium salts is slow.

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“…1 Aziridines undergo ring-opening reactions with a wide range of nucleophiles in the presence of Lewis 1a and Brønsted acids. 2 The majority of examples in the literature involve the ring opening of N-substituted aziridines, equipped with electron-withdrawing substituents such as sulfonyl, 3 phosphoryl, 4 phosphinyl, 5 and acyl, 6 which assist in activating the ring towards opening. The enantioselective versions of these processes have been developed by Jacobsen 7 and by Müller.…”

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confidence: 99%