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Rajeev Sakhuja - One of the best experts on this subject based on the ideXlab platform.
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reducing agent free convergent synthesis of hydroxyimino decorated tetracyclic fused Cinnolines via rhiii catalyzed annulation using nitroolefins
Journal of Organic Chemistry, 2021Co-Authors: Pidiyara Karishma, Chikkagundagal K Mahesha, Sanjay K Mandal, Rajeev SakhujaAbstract:A mild Rh-catalyzed method was developed for the synthesis of hydroxyimino functionalized indazolo[1,2-a]Cinnolines and phthalazino[2,3-a]Cinnolines by reductive [4 + 2] annulation between 1-arylindazolones and 2-aryl-2,3-dihydrophthalazine-1,4-diones with varied nitroolefins. The targeted oxime decorated tetracyclic fused Cinnolines were synthesized via sequential C-H activation/olefin insertion/reduction under reducing-agent-free conditions.
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ruthenium catalyzed c h acylmethylation of n arylphthalazine 1 4 diones with α carbonyl sulfoxonium ylides highway to diversely functionalized phthalazino fused Cinnolines
Chemistry-an Asian Journal, 2019Co-Authors: Pidiyara Karishma, Sanjay K Mandal, Devesh S Agarwal, Biswajit Laha, Rajeev SakhujaAbstract:A direct ortho-Csp2 -H acylmethylation of 2-aryl-2,3-dihydrophthalazine-1,4-diones with α-carbonyl sulfoxonium ylides is achieved through a RuII -catalyzed C-H bond activation process. The protocol featured high functional group tolerance on the two substrates, including aryl-, heteroaryl-, and alkyl-substituted α-carbonyl sulfoxonium ylides. Thereafter, 2-(ortho-acylmethylaryl)-2,3-dihydrophthalazine-1,4-diones were used as potential starting materials for the expeditious synthesis of 6-arylphthalazino[2,3-a]cinnoline-8,13-diones and 5-acyl-5,6-dihydrophthalazino[2,3-a]cinnoline-8,13-diones under Lawesson's reagent and BF3 ⋅OEt2 mediated conditions, respectively. Of these, the BF3 ⋅OEt2 -mediated cyclization proceeded in DMSO as a solvent and a methylene source via dual C-C and C-N bond formations.
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iridium catalyzed 4 2 annulation of 1 arylindazolones with α diazo carbonyl compounds access to indazolone fused Cinnolines
Organic and Biomolecular Chemistry, 2018Co-Authors: Chikkagundagal K Mahesha, Pidiyara Karishma, Sanjay K Mandal, Devesh S Agarwal, Datta Markad, Rajeev SakhujaAbstract:An efficient one-pot Ir-catalyzed method was developed for the synthesis of indazolone-fused Cinnolines by [4 + 2] annulation of 1-arylindazolones with α-diazo carbonyl compounds via sequential C-H activation/carbene insertion/cyclization in a tandem manner. This method has excellent tolerance towards electron-withdrawing and electron-donating functional groups on 1-arylindazolone. This method was also found to be applicable to cyclic α-diazo carbonyl compounds.
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Additive-Driven Rhodium-Catalyzed [4+1]/[4+2] Annulations of N‑Arylphthalazine-1,4-dione with α‑Diazo Carbonyl Compounds
2018Co-Authors: Pidiyara Karishma, Chikkagundagal K Mahesha, Sanjay K Mandal, Devesh S Agarwal, Rajeev SakhujaAbstract:A Rh(III)-catalyzed strategy involving the [4+1] annulation of 2-arylphthalazine-1,4-diones with α-diazo carbonyl compounds was developed, accessing a series of unprecedented hydroxy-dihydroindazolo-fused phthalazines in good to excellent yields. By varying the additive, phthalazino-fused Cinnolines were synthesized under Rh-catalyzed conditions via [4+2] annulation between the same starting materials. Notably, such two strategies showed a good functional group tolerance and high atom efficiency
Baiquan Wang - One of the best experts on this subject based on the ideXlab platform.
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synthesis of Cinnolines and cinnolinium salt derivatives by rh iii catalyzed cascade oxidative coupling cyclization reactions
Journal of Organic Chemistry, 2018Co-Authors: Yanwei Wang, Baiquan WangAbstract:A novel method for the synthesis of Cinnolines and cinnolinium salt derivatives via Rh(III)-catalyzed cascade oxidative coupling/cyclization reaction from Boc-arylhydrazines and alkynes has been developed. The reactions have a broad substrate scope and high stereoselectivity with readily available starting materials and provides an efficient synthetic route for this kind of compounds. A catalytically competent five-membered rhodacycle has been isolated, thus revealing a key intermediate in the catalytic cycle.
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Synthesis of Cinnolines and Cinnolinium Salt Derivatives by Rh(III)-Catalyzed Cascade Oxidative Coupling/Cyclization Reactions
2018Co-Authors: Yanwei Wang, Baiquan WangAbstract:A novel method for the synthesis of Cinnolines and cinnolinium salt derivatives via Rh(III)-catalyzed cascade oxidative coupling/cyclization reaction from Boc-arylhydrazines and alkynes has been developed. The reactions have a broad substrate scope and high stereoselectivity with readily available starting materials and provides an efficient synthetic route for this kind of compounds. A catalytically competent five-membered rhodacycle has been isolated, thus revealing a key intermediate in the catalytic cycle
Yanwei Wang - One of the best experts on this subject based on the ideXlab platform.
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synthesis of Cinnolines and cinnolinium salt derivatives by rh iii catalyzed cascade oxidative coupling cyclization reactions
Journal of Organic Chemistry, 2018Co-Authors: Yanwei Wang, Baiquan WangAbstract:A novel method for the synthesis of Cinnolines and cinnolinium salt derivatives via Rh(III)-catalyzed cascade oxidative coupling/cyclization reaction from Boc-arylhydrazines and alkynes has been developed. The reactions have a broad substrate scope and high stereoselectivity with readily available starting materials and provides an efficient synthetic route for this kind of compounds. A catalytically competent five-membered rhodacycle has been isolated, thus revealing a key intermediate in the catalytic cycle.
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Synthesis of Cinnolines and Cinnolinium Salt Derivatives by Rh(III)-Catalyzed Cascade Oxidative Coupling/Cyclization Reactions
2018Co-Authors: Yanwei Wang, Baiquan WangAbstract:A novel method for the synthesis of Cinnolines and cinnolinium salt derivatives via Rh(III)-catalyzed cascade oxidative coupling/cyclization reaction from Boc-arylhydrazines and alkynes has been developed. The reactions have a broad substrate scope and high stereoselectivity with readily available starting materials and provides an efficient synthetic route for this kind of compounds. A catalytically competent five-membered rhodacycle has been isolated, thus revealing a key intermediate in the catalytic cycle
Pidiyara Karishma - One of the best experts on this subject based on the ideXlab platform.
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reducing agent free convergent synthesis of hydroxyimino decorated tetracyclic fused Cinnolines via rhiii catalyzed annulation using nitroolefins
Journal of Organic Chemistry, 2021Co-Authors: Pidiyara Karishma, Chikkagundagal K Mahesha, Sanjay K Mandal, Rajeev SakhujaAbstract:A mild Rh-catalyzed method was developed for the synthesis of hydroxyimino functionalized indazolo[1,2-a]Cinnolines and phthalazino[2,3-a]Cinnolines by reductive [4 + 2] annulation between 1-arylindazolones and 2-aryl-2,3-dihydrophthalazine-1,4-diones with varied nitroolefins. The targeted oxime decorated tetracyclic fused Cinnolines were synthesized via sequential C-H activation/olefin insertion/reduction under reducing-agent-free conditions.
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ruthenium catalyzed c h acylmethylation of n arylphthalazine 1 4 diones with α carbonyl sulfoxonium ylides highway to diversely functionalized phthalazino fused Cinnolines
Chemistry-an Asian Journal, 2019Co-Authors: Pidiyara Karishma, Sanjay K Mandal, Devesh S Agarwal, Biswajit Laha, Rajeev SakhujaAbstract:A direct ortho-Csp2 -H acylmethylation of 2-aryl-2,3-dihydrophthalazine-1,4-diones with α-carbonyl sulfoxonium ylides is achieved through a RuII -catalyzed C-H bond activation process. The protocol featured high functional group tolerance on the two substrates, including aryl-, heteroaryl-, and alkyl-substituted α-carbonyl sulfoxonium ylides. Thereafter, 2-(ortho-acylmethylaryl)-2,3-dihydrophthalazine-1,4-diones were used as potential starting materials for the expeditious synthesis of 6-arylphthalazino[2,3-a]cinnoline-8,13-diones and 5-acyl-5,6-dihydrophthalazino[2,3-a]cinnoline-8,13-diones under Lawesson's reagent and BF3 ⋅OEt2 mediated conditions, respectively. Of these, the BF3 ⋅OEt2 -mediated cyclization proceeded in DMSO as a solvent and a methylene source via dual C-C and C-N bond formations.
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iridium catalyzed 4 2 annulation of 1 arylindazolones with α diazo carbonyl compounds access to indazolone fused Cinnolines
Organic and Biomolecular Chemistry, 2018Co-Authors: Chikkagundagal K Mahesha, Pidiyara Karishma, Sanjay K Mandal, Devesh S Agarwal, Datta Markad, Rajeev SakhujaAbstract:An efficient one-pot Ir-catalyzed method was developed for the synthesis of indazolone-fused Cinnolines by [4 + 2] annulation of 1-arylindazolones with α-diazo carbonyl compounds via sequential C-H activation/carbene insertion/cyclization in a tandem manner. This method has excellent tolerance towards electron-withdrawing and electron-donating functional groups on 1-arylindazolone. This method was also found to be applicable to cyclic α-diazo carbonyl compounds.
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Additive-Driven Rhodium-Catalyzed [4+1]/[4+2] Annulations of N‑Arylphthalazine-1,4-dione with α‑Diazo Carbonyl Compounds
2018Co-Authors: Pidiyara Karishma, Chikkagundagal K Mahesha, Sanjay K Mandal, Devesh S Agarwal, Rajeev SakhujaAbstract:A Rh(III)-catalyzed strategy involving the [4+1] annulation of 2-arylphthalazine-1,4-diones with α-diazo carbonyl compounds was developed, accessing a series of unprecedented hydroxy-dihydroindazolo-fused phthalazines in good to excellent yields. By varying the additive, phthalazino-fused Cinnolines were synthesized under Rh-catalyzed conditions via [4+2] annulation between the same starting materials. Notably, such two strategies showed a good functional group tolerance and high atom efficiency
Jyhchien Chen - One of the best experts on this subject based on the ideXlab platform.
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uv irradiation enhanced photoluminescence emission of polyfluorenes containing heterocyclic benzo c cinnoline moieties
Macromolecules, 2015Co-Authors: Jyhchien Chen, Hongze LinAbstract:Polyfluorenes (PFO) derivatives, containing different ratios of heterocyclic, electron-withdrawing benzo[c]cinnoline moieties, BF10, BF25, and BF50 were synthesized by Suzuki coupling reaction. Photoluminescence (PL) spectra showed red-shifted emission peaks at around 500 nm for dilute polymer solutions and at around 530 nm for film samples. The PL quantum yields of polymer dilute solutions decreased as the ratios of benzo[c]cinnoline moieties in main chain increased. By UV irradiation (352 nm), the PL intensity of dilute polymer solutions was enhanced. The PL emission enhancement was attributed to the shorter conjugated length and the reduced donor–acceptor interaction caused by oxygen-containing groups that were formed on fluorene moieties by UV irradiation. The enhanced emission could be quenched further by the addition of proton donors such as trifluoroacetic acid. The completely alternating polymer BF50 consisting of fluorene and benzo[c]cinnoline moieties in dilute THF solution showed a linear relat...
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UV-Irradiation-Enhanced Photoluminescence Emission of Polyfluorenes Containing Heterocyclic Benzo[c]cinnoline Moieties
2015Co-Authors: Jyhchien Chen, Hongze LinAbstract:Polyfluorenes (PFO) derivatives, containing different ratios of heterocyclic, electron-withdrawing benzo[c]cinnoline moieties, BF10, BF25, and BF50 were synthesized by Suzuki coupling reaction. Photoluminescence (PL) spectra showed red-shifted emission peaks at around 500 nm for dilute polymer solutions and at around 530 nm for film samples. The PL quantum yields of polymer dilute solutions decreased as the ratios of benzo[c]cinnoline moieties in main chain increased. By UV irradiation (352 nm), the PL intensity of dilute polymer solutions was enhanced. The PL emission enhancement was attributed to the shorter conjugated length and the reduced donor–acceptor interaction caused by oxygen-containing groups that were formed on fluorene moieties by UV irradiation. The enhanced emission could be quenched further by the addition of proton donors such as trifluoroacetic acid. The completely alternating polymer BF50 consisting of fluorene and benzo[c]cinnoline moieties in dilute THF solution showed a linear relationship between UV doses and PL quantum yields after UV irradiation. It exhibited good potential for UV-sensing applications
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synthesis and properties of air stable n channel semiconductors based on meh ppv derivatives containing benzo c cinnoline moieties
Journal of Materials Chemistry C, 2014Co-Authors: Jyhchien Chen, Chijui Chiang, Tuo Chen, Li XingAbstract:In this study we synthesized three novel poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) derivatives that differ in terms of their ratios of heterocyclic benzo[c]cinnoline moieties: P50 containing only MEH-PPV/benzo[c]cinnolinevinylene (BZCV) alternating segments and P25 and P10 containing both MEH-PPV/BZCV alternating segments and MEH-PPV block segments. UV-Vis and PL spectra of these polymers revealed values of λUVmax and λPLmax that ranged from 440 to 489 and from 492 to 551 nm, respectively; these wavelengths blue-shifted upon incorporating additional benzo[c]cinnoline moieties. We also observed energy transfer from the MEH-PPV/BZCV alternating segments to the MEH-PPV block segments. P50, which featured an alternating structure in its main chain, displayed a solvatochromic effect, emitting green light in non-polar solvents and yellow light in polar solvents. The HOMO and LUMO energy levels of these polymers, measured using cyclic voltammetry, ranged from −5.11 to −5.62 and from −3.08 to −3.31 eV, respectively. The incorporation of electron-withdrawing benzo[c]cinnoline moieties enhanced the electron affinity and improved the oxidative stability of the polymers. A bottom-gate, top-contact organic field-effect transistor (OFET) based on P50 exhibited n-channel behavior under ambient conditions, with an electron mobility of 7.8 × 10−3 cm2 V−1 s−1 and an on/off ratio greater than 104. No significant variation in electron mobility can be observed after this OEFT was stored under ambient conditions up to 30 days. To the best of our knowledge, this is the first time that air-stable n-channel MEH-PPV derivatives have ever been reported. It indicated that p-type MEH-PPV can be transformed into n-type materials upon incorporation of benzo[c]cinnoline moieties.