New 4-fluoroalkyl substituted N-phenylpyrazoles: Synthesis promoted by DAST and multinuclear NMR analysis

Bonacorso, Hélio G.; Pittaluga, Everton P.; Porte, Liliane M. F.; Junges, Andrizia F.; Libero, Francieli M.; Zanatta, Nilo; Martins, Marcos A. P.

doi:10.1016/j.jfluchem.2015.05.010

Cited by 5 publications

(4 citation statements)

References 35 publications

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“…Other studies toward unique difluoromethyl-substituted pyrazoles via the deoxofluorination strategy that have appeared in recent years are also worth mentioning. 169,170 In 2019, our group reported practical deoxofluorinations of aliphatic 171 and (hetero)aromatic carboxylic acids 172 to give the trifluoromethyl-substituted derivatives using sulfur tetrafluoride (SF 4 ). In that project, pyrazoles 93, 434, and 435 were easily synthesized on a 10−30 g scale from the corresponding pyrazolecarboxylic acids (Scheme 73).…”

Section: Other Heterocyclizationsmentioning

confidence: 99%

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Fluorinated Pyrazoles: From Synthesis to Applications

2020

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Fluorinated pyrazoles play an important role in medicinal chemistry, drug discovery, agrochemistry, coordination chemistry, and organometallic chemistry. Since the early 1990s, their popularity has grown exponentially. Moreover, more than 50% of all contributions on the topic have been published in the last 5 years. In this review, analysis of novel synthetic approaches to fluorinated pyrazoles that appeared in recent years is performed. A particular emphasis is devoted to a detailed consideration of reaction mechanisms. In addition, the reasons that have led to the ever-increasing popularity of fluorinated pyrazoles in various areas of science are discussed. At the end of the review, several potentially interesting but yet mostly unknown classes of fluorinated pyrazoles are outlined.

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Section: Other Heterocyclizationsmentioning

confidence: 99%

“…Other studies toward unique difluoromethyl-substituted pyrazoles via the deoxofluorination strategy that have appeared in recent years are also worth mentioning. , …”

Section: Preparation Of Fluoroalkyl-substituted Pyrazolesmentioning

confidence: 99%

Fluorinated Pyrazoles: From Synthesis to Applications

2020

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“…demonstrated an ANRORC rearrangement in 2‐trifluoromethyl‐tetrahydro‐2 H ‐chromenones 151 when treated with hydrazine hydrate 54 for the synthesis of 4‐functionalized 3(5)‐trifluoromethyl‐1 H ‐pyrazoles 152 in good yields (Scheme 43). [131] S N (ANRORC) degenerate ring transformation was rationalized through the initial removal of the most acidic proton of the chromenones 151 by the hydrazine hydrate 54 , followed by simultaneous opening of pyran ring with generation of two 1,3‐dicarbonyl compounds linked to each other by a methylaryl unit in the intermediates ( 151 A – B ). Pyrazole formation involved the nucleophilic attack of the hydrazine 54 on the more reactive COCF 3 of the intermediate 151 B followed by intramolecular cyclization.…”

Section: Trifluoromethyl‐β‐dicarbonyls Based Synthesis Of Heterocyclesmentioning

confidence: 99%

Trifluoromethyl‐β‐dicarbonyls as Versatile Synthons in Synthesis of Heterocycles

Sumran,

Jain,

Kumar

et al. 2024

Chemistry A European J

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Trifluoromethyl group relishes a privileged position in the realm of medicinal chemistry because its incorporation into organic molecules often enhances the bioactivity by altering pharmacological profile of molecule. Trifluoromethyl‐β‐dicarbonyls have emerged as pivotal building blocks in synthetic organic chemistry due to their facile accessibility, stability and remarkable versatility. Owing to presence of nucleophilic and electrophilic sites, they offer multifunctional sites for the reaction. This review covers a meticulous exploration of their multifaceted role, encompassing an in‐depth analysis of mechanism, extensive scope, limitations and wide‐ranging applications in diverse organic synthesis, covering the literature from the 21st century. This comprehensive review encapsulates the applications of trifluoromethyl‐β‐dicarbonyls and their synthetic equivalents as precursors of complex and diverse heterocyclic scaffolds, fused heterocycles and spirocyclic compounds having medicinal and material importance. Their potent synthetic utility in cyclocondenation reactions with binucleophiles, cycloaddition reactions, C‐C bond formations, asymmetric multicomponent reactions using classical/solvent‐free/catalytic synthesis have been presented. Influence of unsymmetrical trifluoromethyl‐β‐diketones on regioselectivity of transformation is also reviewed. This review will benefit the synthetic and pharmaceutical communities to explore trifluoromethyl‐β‐dicarbonyls as trifluoromethyl building blocks for fabrication of heterocyclic scaffolds having implementation into drug discovery programs in the imminent future.

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“…The important biological properties of sydnones were reviewed recently [ 25 ]. On the other hand, 1-phenylpyrazoles generated by 1,3-dipolar cycloaddition between sydnones as dipoles and dimethylacetylene dicarboxylate as alkyne dipolarophile are also important bioactive scaffolds [ 26 , 27 ]…”

Section: Introductionmentioning

confidence: 99%

Synthesis of 1-(2-Fluorophenyl)pyrazoles by 1,3-Dipolar Cycloaddition of the Corresponding Sydnones

et al. 2021

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3-Arylsydnones bearing fluorine and bromine atoms on the benzene ring were synthesized from N-nitroso-2-fluorophenylglycines and characterized by NMR spectroscopy. These were employed further in synthesis of the corresponding 1-(2-fluorophenyl)pyrazoles by 1,3-dipolar cycloaddition reaction with dimethyl acetylenedicarboxylate (DMAD) as activated dipolarophile. The sydnones as reaction intermediates were characterized by single crystal X-ray diffraction analysis showing interesting features such as halogen bonding as an important interaction in modeling the crystal structure.

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New 4-fluoroalkyl substituted N-phenylpyrazoles: Synthesis promoted by DAST and multinuclear NMR analysis

Cited by 5 publications

References 35 publications

Fluorinated Pyrazoles: From Synthesis to Applications

Fluorinated Pyrazoles: From Synthesis to Applications

Trifluoromethyl‐β‐dicarbonyls as Versatile Synthons in Synthesis of Heterocycles

Synthesis of 1-(2-Fluorophenyl)pyrazoles by 1,3-Dipolar Cycloaddition of the Corresponding Sydnones

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