ChemInform Abstract: Heterogeneous SnCl2/SiO2 versus Homogeneous SnCl2 Acid Catalysis in the Benzo[N,N]‐heterocyclic Condensation.

Darabi, Hossein Reza; Aghapoor, Kioumars; Mohsenzadeh, Farshid; Jalali, Mohammad Reza; Talebian, Shiva; Ebadinia, Leila; Khatamifar, Ehsan; Aghaee, Ali

doi:10.1002/chin.201122178

Cited by 2 publications

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“…Bis(hexyloxy)triphenylamine bromide was prepared according to literature procedures. 53 Diethyl 2,3-dioxosuccinate, 54 dimethyl 4,4′-oxalyldibenzoate, 55 and the SnCl 2 / SiO 2 solid support catalyst 43 were prepared according to literature procedures. Thin-layer chromatography (TLC) was visualized with UV.…”

Section: ■ Conclusionmentioning

confidence: 99%

“…36,41,42 Condensation with electron-rich 4,4′-dimethoxybenzil required alternate conditions involving a SnCl 2 /SiO 2 solid support Lewis acid catalyst to give appreciable amounts of 4d (44%). 43 Finally, the TPz D−A−D dyes (TPz−Et, TPz−CO 2 Et, TPz−Ph, TPz−PhOMe, TPz−PhCO 2 Me) were obtained by Pd-catalyzed direct C−H arylation reaction of 4a−4e in yields ranging from 68%−35% with the use of X-Phos 38 or PtBu 3 39 as ligand. The palladiumcatalyzed C−H activation conditions were optimized with TPz−Et.…”

Section: ■ Introductionmentioning

confidence: 99%

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Donor–Acceptor–Donor Thienopyrazines via Pd-Catalyzed C–H Activation as NIR Fluorescent Materials

et al. 2015

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A series of thienopyrazine-based donor–acceptor–donor (D–A–D) near-infrared (NIR) fluorescent compounds were synthesized through a rapid, palladium-catalyzed C–H activation route. The dyes were studied through computational analysis, electrochemical properties analysis, and characterization of their photophysical properties. Large Stokes shifts of approximately 175 nm were observed, which led to near-infrared emission. Computational evaluation shows that the origin of this large Stokes shift is a significant molecular reorganization particularly about the D–A bond. The series exhibits quantum yields of up to φ = >4%, with emission maxima ranging from 725 to 820 nm. The emission is strong in solution, in thin films, and also in isolation at the single-molecule level. Their stable emission at the single-molecule level makes these compounds good candidates for single-molecule photon sources in the near-infrared.

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Section: ■ Conclusionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Donor–Acceptor–Donor Thienopyrazines via Pd-Catalyzed C–H Activation as NIR Fluorescent Materials

et al. 2015

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“…As part of our research program on silica-supported Lewis acids for the acid-catalyzed reactions (Darabi et al 2009(Darabi et al , 2011, herein, we introduce silica-supported antimony(III) chloride (SbCl 3 /SiO 2 ) as a novel mild heterogeneous catalyst for the Paal-Knorr pyrrole cyclocondensation reaction (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

Silica-supported antimony(III) chloride as a mild and reusable catalyst for the Paal–Knorr pyrrole synthesis

et al. 2011

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Heterogeneous catalysts are used for control of environmental pollution. Heterogeneous catalysts are easily separated from the reaction mixture, thus allowing their recovery and re-use. There is a need for catalysts that are efficient under mild conditions. Here, we show that silicasupported antimony(III) chloride (SbCl 3 /SiO 2 ) acts as a highly efficient heterogeneous Lewis acid catalyst for the Paal-Knorr pyrrole synthesis at room temperature. We found that condensation of hexane-2,5-dione with aromatic and aliphatic primary amines in hexane using SbCl 3 /SiO 2 with 7.6 wt% SbCl 3 was the best reaction condition. The silica support facilitated the workup of the reaction mixture and provided a reusable catalyst at least for 7 runs without significant loss in activity. Indeed, the yield was 98% for the first run and 84% for the 7th run. We conclude that low catalyst loading, operational simplicity, practicability and applicability to various substrates make this reaction an interesting alternative to previously applied procedures. From the environmental standpoint, this eco-friendly catalyst is stable, highly active, easy to prepare and handle.

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ChemInform Abstract: Heterogeneous SnCl₂/SiO₂ versus Homogeneous SnCl₂ Acid Catalysis in the Benzo[N,N]‐heterocyclic Condensation.

Cited by 2 publications

References 1 publication

Donor–Acceptor–Donor Thienopyrazines via Pd-Catalyzed C–H Activation as NIR Fluorescent Materials

Donor–Acceptor–Donor Thienopyrazines via Pd-Catalyzed C–H Activation as NIR Fluorescent Materials

Silica-supported antimony(III) chloride as a mild and reusable catalyst for the Paal–Knorr pyrrole synthesis

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