Synthesis of 2‐Substituted 1,3‐Benzoselenazoles from Carboxylic Acids Promoted by Tributylphosphine

Radatz, Cátia S.; Rampon, Daniel S.; Balaguez, Renata A.; Alves, Diego; Schneider, Paulo H.

doi:10.1002/ejoc.201402808

Cited by 32 publications

(22 citation statements)

References 90 publications

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“… The different synthetic approaches toward the preparation of 2‐functionalised benzoselenazole derivatives starting from: a) 2‐selenoanilides (R 1 =Me or aryl; R 2 =Me or Et); b) bis(2‐aminophenyl)diselenide (R 1 =alkyl or aryl); c) 2‐iodoanilides (R 1 =alkyl, aryl or heteroaryl); and d) 2‐iodoaniline (R 1 =aryl or heteroaryl) …”

Section: Resultsmentioning

confidence: 99%

“…Recently, two new synthetic routes toward the preparation of alkyl‐, aryl‐ and heteroaryl‐substituted derivatives have been developed (routes b and d). In route b, bis(2‐aminophenyl)diselenide is reacted with a carbonyl derivative in the presence of a reducing agent, whereas the second approach exploits Woollins’ reagent and 2‐iodoanilides (route c) . Finally, a copper‐catalysed three‐component one‐pot synthesis, limited to the case of aryl and heteroaryl derivatives, has been described very recently (route d) .…”

Section: Resultsmentioning

confidence: 99%

“…Inspired by the synthetic route developed by Christiaens and co-workers, [40] we focused our attentiono nt he dehydra- Scheme1.The different synthetic approaches toward the preparation of 2-functionalised benzoselenazole derivatives startingf rom:a )2-selenoanilides (R 1 = Me or aryl;R 2 = Me or Et); [40] b) bis(2-aminophenyl)diselenide (R 1 = alkyl or aryl); [44,45] c) 2-iodoanilides (R 1 = alkyl, aryl or heteroaryl);and [47] d) 2-iodoaniline (R 1 = aryl or heteroaryl). [48] tive cyclization reaction to preparet he targeted 2-substituted chalcogenazole derivatives.…”

Section: Synthesismentioning

confidence: 99%

See 2 more Smart Citations

Supramolecular Wiring of Benzo‐1,3‐chalcogenazoles through Programmed Chalcogen Bonding Interactions

Kremer

Fermi

Biot

et al. 2016

Chemistry A European J

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112

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The high-yielding synthesis of 2-substituted benzo-1,3-tellurazoles and benzo-1,3-selenazoles through a dehydrative cyclization reaction has been reported, giving access to a large variety of benzo-1,3-chalcogenazoles. Exceptionally, these aromatic heterocycles proved to be very stable and thus very handy to form controlled solid-state organizations in which wire-like polymeric structures are formed through secondary N⋅⋅⋅Y bonding interactions (SBIs) engaging the chalcogen (Y=Se or Te) and nitrogen atoms. In particular, it has been shown that the recognition properties of the chalcogen centre at the solid state could be programmed by selectively barring one of its σ-holes through a combination of electronic and steric effects exerted by the substituent at the 2-position. As predicted by the electrostatic potential surfaces calculated by quantum chemical modelling, the pyridyl groups revealed to be the stronger chalcogen bonding acceptors, and thus the best ligand candidate for programming the molecular organization at the solid state. In contrast, the thiophenyl group is an unsuitable substituent for establishing SBIs in this molecular system as it gives rise to chalcogen-chalcogen repulsion. The weaker chalcogen donor properties of the Se analogues trigger the formation of feeble N⋅⋅⋅Se contacts, which are manifested in similar solid-state polymers featuring longer nitrogen-chalcogen distances.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Synthesismentioning

confidence: 99%

See 1 more Smart Citation

Supramolecular Wiring of Benzo‐1,3‐chalcogenazoles through Programmed Chalcogen Bonding Interactions

Kremer

Fermi

Biot

et al. 2016

Chemistry A European J

115

112

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“…Unfortunately, we were unable to apply the same strategy to prepare the selenium and tellurium analogues because the syntheses of the corresponding 2‐ H ‐1,3‐benzoselenazole36, 37, 56 and 2‐ H ‐1,3‐benzotellurazole56 were characterised by low yields. It is only recently that an efficient synthesis of 2‐ H ‐1,3‐benzoselenazole has appeared in the literature 57…”

Section: Resultsmentioning

confidence: 99%

Walking Down the Chalcogenic Group of the Periodic Table: From Singlet to Triplet Organic Emitters

Kremer

Aurisicchio

Leo

et al. 2015

Chemistry A European J

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The synthesis, X-ray crystal structures, ground- and excited-state UV/Vis absorption spectra, and luminescence properties of chalcogen-doped organic emitters equipped on both extremities with benzoxa-, benzothia-, benzoselena- and benzotellurazole (1X and 2X ) moieties have been reported for the first time. The insertion of the four different chalcogen atoms within the same molecular skeleton enables the investigation of only the chalcogenic effect on the organisation and photophysical properties of the material. Detailed crystal-structure analyses provide evidence of similar packing for 2O -2Se , in which the benzoazoles are engaged in π-π stacking and, for the heavier atoms, in secondary X⋅⋅⋅X and X⋅⋅⋅N bonding interactions. Detailed computational analysis shows that the arrangement is essentially governed by the interplay of van der Waals and secondary bonding interactions. Progressive quenching of the fluorescence and concomitant onset of phosphorescence features with gradually shorter lifetimes are detected as the atomic weight of the chalcogen heteroatom increases, with the tellurium-doped derivatives exhibiting only emission from the lowest triplet excited state. Notably, the phosphorescence spectra of the selenium and tellurium derivatives can be recorded even at room temperature; this is a very rare finding for fully organic emitters.

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“…In this sense and aiming our continuous interest in the synthesis of chalcogen compounds, − the present study describes a novel methodology involving in situ reduction of elemental selenium to generate a nucleophilic Se 2– species in superbasic media [KOH and dimethylsulfoxide (DMSO)] to produce 2,5-disubstituted photoactive selenophenes. The scope of the methodology was investigated using 1,3-diyne derivatives containing different substituents with electron-donating and electron-withdrawing features in different positions to verify electronic and steric effects.…”

Section: Introductionmentioning

confidence: 99%

Evidence of a Photoinduced Electron-Transfer Mechanism in the Fluorescence Self-quenching of 2,5-Substituted Selenophenes Prepared through In Situ Reduction of Elemental Selenium in Superbasic Media

et al. 2021

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A series of new 2,5-disubstituted selenophene derivatives are described from elemental selenium and 1,3-diynes in superbasic media. The activation of elemental selenium in a KOH/DMSO system allows cyclization with conjugated diynes at room temperature. The cyclization reaction is extended to a broad range of functional groups, for which photophysics were experimentally and theoretically investigated. The selenophene derivatives present absorption maxima in the UV-A region and fluorescence emission in the violet-toblue region. Fluorescence decay profiles were obtained showing a monoexponential decay with fast fluorescence lifetimes (∼0.118 ns), as predicted by the Strickler−Berg relations. In general, in both investigations, no dependence on the solvent polarity on the absorption and emission maxima location was observed. On the other hand, solvents and substituents are shown to play a role in the fluorescence quantum yield values. In addition, a fluorescence selfquenching behavior could be observed, related to a photoinduced electron-transfer mechanism. Theoretical calculations performed at the MP2/ADC(2)/cc-pVDZ level of theory were performed in order to investigate the photophysical features of this series of selenophene derivatives.

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Synthesis of 2‐Substituted 1,3‐Benzoselenazoles from Carboxylic Acids Promoted by Tributylphosphine

Cited by 32 publications

References 90 publications

Supramolecular Wiring of Benzo‐1,3‐chalcogenazoles through Programmed Chalcogen Bonding Interactions

Supramolecular Wiring of Benzo‐1,3‐chalcogenazoles through Programmed Chalcogen Bonding Interactions

Walking Down the Chalcogenic Group of the Periodic Table: From Singlet to Triplet Organic Emitters

Evidence of a Photoinduced Electron-Transfer Mechanism in the Fluorescence Self-quenching of 2,5-Substituted Selenophenes Prepared through In Situ Reduction of Elemental Selenium in Superbasic Media

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