- Novel bipyrazolo[1,5-: A] pyridine luminogens with aggregation-induced emission enhancement properties
-
A novel 3,3′-bipyrazolo[1,5-a]pyridine molecular scaffold was obtained as a product of serendipity. Both photophysical characterisations and HOMO-LUMO theoretical calculations indicate its potential as a promising fluorophore with notable intramolecular charge transfer. Nonetheless, the emission properties of this compound suffer from the typical aggregation-caused quenching effect. To overcome this situation, we introduced additional diaryl groups onto the skeleton and synthesised a series of 7,7′-diaryl-3,3′-bipyrazolo[1,5-a]pyridines via palladium-catalysed intermolecular C-H/C-H bond cross-coupling reaction in 35-62% yields. This series of tailor-made luminogens with twisted π-structures display aggregation-induced emission enhancement properties.
- Hsiao, Pu-Yen,Chu, Jean-Ho
-
supporting information
p. 12281 - 12284
(2021/11/30)
-
- Pyrido[1',2':1,5]pyrazolo[4,3-b]quinolines as New Fluorescent Heterocyclic Systems for Dye-Sensitized Solar Cells
-
Abstract: New fluorescent heterocyclic compounds pyrido[1',2':1,5]pyrazolo[4,3-b]quinolines have been synthesized by the reaction of 3-nitropyrazolo[1,5-a]pyridine with different arylacetonitriles in high yield. Structural assignments of the new compounds
- Agheli, Z.,Beyramabadi, S. A.,Davoodnia, A.,Pordel, M.
-
p. 1345 - 1350
(2020/08/14)
-
- Synthesis, characterization, optical properties, computational characterizations, QTAIM analysis and cyclic voltammetry of new organic dyes for dye-sensitized solar cells
-
In recent years, dye-sensitized solar cells (DSSCs) have regarded as potential solar cells for the next generation of photovoltaic technologies. Many organic compounds are explored and used in DSSCs to produce low-cost devices and improve the cell efficiency. In this work, three new heterocyclic purple dyes are synthesized from the reaction of 3-nitropyrazolo[1,5-a]pyridine with various arylacetonitriles for dye-sensitized solar cells (DSSCs), exhibiting high molar extinction coefficients and a broad absorption range led to the good photovoltaic performance of 6.95–7.18%. Physical spectral, analytical data and optical properties are established the structures of the new dyes. The optimized geometries and relevant frontier orbitals of the dyes are obtained by density functional theory (DFT) at the level of B3LYP/6-311 + G(d,p). Electrostatic potential maps and electron density maps of the dyes were also obtained by atoms in molecules (AIM) analysis. Cyclic voltammetry measurement was performed to evaluate the electrochemical properties of the dyes and reversible oxidation waves were observed for them.
- Agheli, Zahra,Pordel, Mehdi,Beyramabadi, Safar Ali
-
-
- Regioselective Metalation and Functionalization of the Pyrazolo[1,5- a]pyridine Scaffold Using Mg- and Zn-TMP Bases
-
A regioselective functionalization of the pyrazolo[1,5-a]pyridine scaffold using Mg- and Zn-TMP bases (TMP = 2,2,6,6-tetramethylpiperidyl) in the presence or absence of BF3·OEt2 is described. Also, various functionalized pyrazolo[1,5-a]pyridines bearing an ester function (and an NHBoc or ethyl group) are magnesiated and functionalized, leading to polysubstituted heterocycles. Additionally, a sulfoxide directed ortho-metalation, followed by the transition-metal-free amination of a pyrazolo[1,5-a]pyridine sulfoxide, using a magnesium amide, is reported.
- Balkenhohl, Moritz,Salgues, Bruno,Hirai, Takahiro,Karaghiosoff, Konstantin,Knochel, Paul
-
supporting information
p. 3114 - 3118
(2018/05/28)
-
- Development of Structurally Diverse N-Heterocyclic Carbene Ligands via Palladium-Copper-Catalyzed Decarboxylative Arylation of Pyrazolo[1,5-a]pyridine-3-carboxylic Acid
-
A series of fused non-classical normal N-heterocyclic carbenes, Pyrpy-NHC precursors derived from pyrazolo[1,5-a]pyridines, has been prepared using palladium-copper-catalyzed decarboxylative arylation of pyrazolo[1,5-a]pyridine-3-carboxylic acid. Air-stable palladium and rhodium complexes of these ligands have been synthesized via mild transmetallation of Ag-Pyrpy-NHC. The structural properties of Rh(Pyrpy-NHC)(COD)Cl complexes were determined via X-ray analysis. The measurement of the CO stretching frequencies of dicarbonyl Rh-Pyrpy-NHC complexes revealed that the electron donating strength of Pyrpy-NHC could be tuned by varying the substituents of the aryl group. A catalytic study of the Pd-Pyrpy-NHC complexes revealed promising activity in the Suzuki–Miyaura reaction under ambient atmospheric conditions. (Figure presented.).
- Alam, Khyarul,Kim, Seong Min,Kim, Do Joong,Park, Jin Kyoon
-
supporting information
p. 2661 - 2670
(2016/08/31)
-
- Optimized scale up of 3-pyrimidinylpyrazolo[1,5-a]pyridine via Suzuki coupling; A general method of accessing a range of 3-(hetero)arylpyrazolo[1,5-a] pyridines
-
We have developed an improved synthesis of 3-(hetero)aryl pyrazolo[1,5-a]pyridines (such as 3-(2,5-dichloropyrimidin-4-yl)pyrazolo[1,5-a] pyridine (8)) via an optimized synthesis and Suzuki coupling of 3-pyrazolo[1,5-a]pyridine boronic ester 10. These conditions are applicable to both high throughput chemistry and large scale synthesis of these medicinally important compounds. The scope of this chemistry has been further extended to include the synthesis and coupling of a novel boronic ester, 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-6,7-dihydro-5H-pyrazolo[5,1-b] [1,3]oxazine (43).
- Bethel, Paul A.,Campbell, Andrew D.,Goldberg, Frederick W.,Kemmitt, Paul D.,Lamont, Gillian M.,Suleman, Abid
-
p. 5434 - 5444
(2012/09/08)
-
- Azaindole Derivatives with High Affinity for the Dopamine D4 Receptor: Synthesis, Ligand Binding Studies and Comparison of Molecular Electrostatic Potential Maps
-
Piperazinylmethyl substituted pyrazolopyridines and related heterocycles were synthesized and found to recognize selectivity the dopamine D4 receptor. For the most potent derivative 10d a Ki value of 2.0 nM was observed. SAR studies including the comparison of molecular isopotential surfaces were performed.
- Loeber, Stefan,Huebner, Harald,Gmeiner, Peter
-
-
- NITROOLEFINS. I. A NEW AND CONVENIENT ACCESS TO INDOLIZINES AND PYRAZOLOPYRIDINES USING 1-NITRO-2-(PHENYLTHIO>ETHYLENE
-
1-Nitro-2-(phenylthio)ethylene (1) reacts with a variety of N-ylides and N-imines (pyridinium, isoquinolinium, quinolinium, phthalazinium N-ylides and N-imines) in the presence of triethylamine to give the corresponding fused pyrrole and pyrazole derivatives (indolizines, pyrroloisoquinoline, pyrrolophthalazine, pyrazolopyridine, pyrazoloquinoline, and pyrazoloisoquinoline) along with the corresponding 1-nitropyrrolopyridines and 1-nitropyrazolopyridines, respectively, in moderate yields.
- Tominaga, Yoshinori,Ichihara, Yuichi,Hosomi, Akira
-
p. 2345 - 2348
(2007/10/02)
-
- Thermal Rearrangements of Cyclic Amine Ylides. III. Intramolecular Cyclization of 2-Ethynylpyridine N-Imides to 3-Azaindolizine Derivatives
-
Treatment of the N-aminopyridinium salts (5a-e) prepared from 2-ethynylpyridines (4) with potassium carbonate resulted in an intramolecular cyclization to give the corresponding 3-azaindolizines (6) (pyrazolopyridines), presumably via the ionic in
- Tsuchiya, Takashi,Sashida, Haruki,Konoshita, Ari
-
p. 4568 - 4572
(2007/10/02)
-
- 1,3-Dipolar Addition of Pyridine N-Imine to Acetylenes and the Use of C-13 NMR in Several Structural Assignments
-
Addition of pyridine-N-imine to a variety of acetylenic mono- (Scheme I) and di- (Scheme II) carboxylic ester dipolarophiles was carried out.Several of the 3-azapyrrocoline esters obtained were further converted into acids, amides and hydrazides as shown in Schemes I and II.
- Anderson, Paul L.,Hasak, James P,Kahle, Alicia D.,Paolella, Nicholas A.,Shapiro, Michael J.
-
p. 1149 - 1152
(2007/10/02)
-
- Rearrangement of 2-Ethynylpyridinium N-Imides to Pyrazolopyridines
-
Pyrazolopyridines (6) are obtained from the N-amino-2-ethynylpyridinium salts (5) on treatment with base.
- Tsuchiya, Takashi,Sashida, Haruki
-
p. 1109 - 1110
(2007/10/02)
-
