- Thiolate-Initiated Synthesis of Dibenzothiophenes from 2,2′-Bis(methylthio)-1,1′-Biaryl Derivatives through Cleavage of Two Carbon-Sulfur Bonds
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A catalytic reaction involving the cleavage of two carbon-sulfur bonds in 2,2′-bis(methylthio)-1,1′-biaryl derivatives is reported. This reaction does not require a transition-metal catalyst and is promoted by a thiolate anion. Notably, based on DFT calculations, the product-forming cyclization step is shown to proceed through a concerted nucleophilic aromatic substitution (CS N Ar) mechanism.
- Chatani, Naoto,Kawashima, Yuki,Kodama, Takuya,Masuya, Yoshihiro,Tobisu, Mamoru
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p. 1995 - 1999
(2019/10/22)
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- Synthesis of functionalized dibenzothiophenes- An efficient three-step approach based on Pd-catalyzed C-C and C-S bond formations
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A novel and efficient three-step protocol for synthesizing functionalized dibenzothiophenes (DBTs) from common starting materials and by using palladium-catalyzed carbon-carbon and carbon-sulfur bond formations is presented. The reaction conditions offer significantly improved functional-group tolerance and regioselectivity as compared to previously reported methods. A flexible and concise three-step protocol for the synthesis of functionalized dibenzothiophenes DBTs from readily available starting materials is presented. The method is based on two palladium-catalyzed reactions to prepare the masked thiophenols 4followed by deprotection and in situ cyclization to form the DBT skeleton. This approach offers improved functional-group tolerance as well as regiocontrol in the synthesis of functionalized DBTs as compared to previously reported methods.
- Jepsen, Tue Heesgaard,Larsen, Mogens,Jorgensen, Morten,Solanko, Katarzyna A.,Bond, Andrew D.,Kadziola, Anders,Nielsen, Mogens Brondsted
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- CARBAZOLE-CONTAINING MATERIALS IN PHOSPHORESCENT LIGHT EMITTING DIODES
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Carbazole-containing compounds are provided. In particular, the compounds are oligocarbazole-containing compounds having an unsymmetrical structure. The compounds may be useful in organic light emitting devices, in particular as hosts in the emissive layer of such devices.
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- Synthesis and evaluation of isosteres of N-methyl indolo[3,2-b]-quinoline (cryptolepine) as new antiinfective agents
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Isosteres of cryptolepine (1) were synthesized and evaluated for their antiinfective activities. Overall, the sulfur isostere, 5-methyl benzothieno[3,2-b]quinolinium salt (5b), was equipotent to 1 and has shown no cytotoxicity at 23.8 μg/mL. Compound 5b was also found to have a broad spectrum of activity. Both the carbon and oxygen isosteres were less potent than cryptolepine. A limited library of 2-substituted analogs of 5b has been synthesized and evaluated in antifungal screens but did not show increase in potency compared to the unsubstituted 5b. Similarly, evaluation of tricyclic benzothieno[3,2-b]pyridines while showing promise in individual screens did not produce an overall increase in potency. Overall, the evaluation of the activities of 5b compared with standard antifungal/anti-protozoal agents suggests that the benzothienoquinoline scaffold could serve as a lead for optimization.
- Zhu, Xue Y.,Mardenborough, Leroy G.,Li, Shouming,Khan, Abdul,Zhang, Wang,Fan, Pincheng,Jacob, Melissa,Khan, Shabana,Walker, Larry,Ablordeppey, Seth Y.
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p. 686 - 695
(2007/10/03)
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- New entry to benzo[b]thieno[2,3-b]- and benzo[b]thieno-[3,2-b]-pyridines using 2- and 3-azidobenzo[b]thiophene as the nitrogen precursors
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N-(3-Benzo[b]thienyl)- and N-(2-benzo[b]thienyl)-iminotriphenylphosphorane - prepared from the corresponding azidobenzo[b]thiophenes - react with α,β-unsaturated aldehydes under mild conditions to give directly benzo-[b]thieno[3,2-b]- and benzo[b]thieno[2
- Degl'Innocenti, Alessandro,Funicello, Maria,Scafato, Patrizia,Spagnolo, Piero,Zanirato, Paolo
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p. 2561 - 2563
(2007/10/03)
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