Synthesis of novel pyrazoles via [2+3]-dipolar cycloaddition using alkyne surrogates

Dadiboyena, Sureshbabu; Valente, E.; Hamme, Ashton T.

doi:10.1016/j.tetlet.2010.01.017

Cited by 49 publications

(9 citation statements)

References 22 publications

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“…[219][220][221] It is a selective COX-II inhibitor established by Pzer company and sold under the brand name of Celebrex®. [222][223][224] Various approaches were reported for the formation of pyrazoles mostly based on 1,3-dipolar cycloadditions [225][226][227][228][229][230][231] or condensation reactions [232][233][234][235][236] as a key stage. It can be prepared by a reaction of 4-methyl-acetophenone 178 with N-(triuoroacetyl)imidazole 179 in the presence of sodium bis(trimethylsilyl) amide to give the 4,4,4-triuoro-1-(p-tolyl)butane-1,3-dione 180.…”

Section: Five-membered Heterocyclesmentioning

confidence: 99%

Prescribed drugs containing nitrogen heterocycles: an overview

2020

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Section: Five-membered Heterocyclesmentioning

confidence: 99%

Prescribed drugs containing nitrogen heterocycles: an overview

2020

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“…This orientation is a function of the electron distribution of 1,3-dipolar and alkene (Scheme 3). [18] Since the rigid and conjugated structure of synthesized compounds makes them extremely fluorescent, we decided to investigate their photophysical properties. Therefore, the UV absorption and fluorescence emission spectra of all synthesized chromeno[4,3-b]pyrazolo[3,4-d]pyridin-4(3H)-ones were explored in EtOH as a convenient solvent and except for 4 d, large Stokes shifts were observed for them.…”

Section: Resultsmentioning

confidence: 99%

Design and Synthesis of Coumarin‐Based Pyrazolopyridines as Biocompatible Fluorescence Dyes for Live‐Cell Imaging

et al. 2020

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An unprecedented strategy for the synthesis of highly fluorescent chromeno[4,3-b]pyrazolo[3,4-d]pyridin-4(3H)-ones via a 1,3-dipolar cycloaddition reaction/ring closure in the presence of NH 4 OAc/air oxidation in a one-pot procedure is described. The molecular structures were characterized by IR spectrophotometry, mass spectrometry, NMR spectroscopy, and single-crystal X-ray analysis. Furthermore, the photophysical properties of synthesized compounds were studied by absorption and fluorescence spectroscopy. All of the compounds exhibited almost similar spectra due to their resembling molecular structures. Therefore, one of the synthesized coumarin-based pyrazolopyridines was selected to evaluate its application as a live-cell imaging agent by an inverted phasecontrast microscope. The result reveals that synthesized chromeno[4,3-b]pyrazolo[3,4-d]pyridin-4(3H)-one has acceptable photostability, low cytotoxicity, satisfactory fluorescence efficiency (Φ f : 0.53), and excellent capability to penetrate into the intracellular space. Accordingly, it can be rendered as a promising dye in fluorescence bioimaging. Chemoselectivity, simple and available starting materials, operational simplicity, and good yields are other outstanding advantages of this reaction.

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“…In 2010, the synthesis of tetrasubstituted pyrazoles 74 in high yields was proposed through the regioselective 1,3‐dipolar cycloaddition of 3‐aryl‐2‐bromo‐propenal to C ‐aryl‐ N ‐phenylnitriles ( 73 ; Scheme ) …”

Section: Pyrazoles Pyrazolines and Pyrazolidinesmentioning

confidence: 99%

Synthesis of Diheteroatomic Five‐Membered Heterocyclic Compounds from α,β‐Unsaturated Aldehydes

Keiko

Вчисло

2016

Asian J Org Chem

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The recent increasei ni nterest in the chemistry of azoles has been owing to their paramount importance in several essential fields of research, such as pharmacology, medicine, biology, the organic synthesis of fine chemicals, agriculturalc hemistry, and the chemical industry.T his Focus Review summarizes and highlights recently developed methods for the synthesis of five-membered N,N-, N,O-, andN ,Sheterocycles based on the transformations of 2-alkenals. Over the last 15 years, these reactions, which often differ from reactions involving other a,b-unsaturatedc arbonyl compoundsi nt erms of methoda nd results, have gathered significant momentum. The multitude of catalytic and tech-nological novelties discussed in this Focus Review,s uch as asymmetricm etal-and organocatalysis,o ne-pot multicomponent reactions that proceed through domino, cascade, or tandem sequences, and microwave activation,p romote the formation of ad iverse range of target products, the structures of which becomec lear from the mechanistic schemes given in this Focus Review.T he mechanisms discussed reflect great advances in the chemo-, regio-, and stereoselectivity of the reactions of 2-alkenals, which allows new azoles and related compounds (imidazoles, pyrazoles, oxazoles, thiazoles, and their hydrogenatedd erivatives) to be synthesized.[a] Prof.The ORCID identification number(s) for the author(s) of this articlecan be found under http://dx.Scheme2.One-potsynthesis of imidazoles 8 and tentativemechanism of the reaction.T s= 4-toluenesulfonyl, TMS = tert-butyltrimethylsilyl, Bn = benzyl, Lg = leaving group.Scheme3.Enantioselective synthesiso f3-hydroxyalkyl and 3-aminoalkyli midazo[1,2-a]pyridines (9)through an asymmetricorganocatalytic [3+ +2] annulation strategy.Alk = alkyl.Scheme4.One-potsynthesis of imidazole-containingc ondensed heterocycles by the reaction of 2-alkoxypropenalswith N-binucleophiles.Scheme9.Aroute to 2-(1'-alkoxyvinyl)imidazolidines 27 through the condensation of alkoxy propenals.

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Synthesis of novel pyrazoles via [2+3]-dipolar cycloaddition using alkyne surrogates

Cited by 49 publications

References 22 publications

Prescribed drugs containing nitrogen heterocycles: an overview

Prescribed drugs containing nitrogen heterocycles: an overview

Design and Synthesis of Coumarin‐Based Pyrazolopyridines as Biocompatible Fluorescence Dyes for Live‐Cell Imaging

Synthesis of Diheteroatomic Five‐Membered Heterocyclic Compounds from α,β‐Unsaturated Aldehydes

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