5459-40-5Relevant academic research and scientific papers
Fast and Regioselective Polymerization of para-Alkoxystyrene by Palladium Catalysts for Precision Production of High-Molecular-Weight Polystyrene Derivatives
Liao, Guangfu,Xiao, Zefan,Chen, Xiaolin,Du, Cheng,Zhong, Liu,Cheung, Chi Shing,Gao, Haiyang
, p. 256 - 266 (2020/01/09)
Polymerization of polar vinyl monomers by a coordination-insertion approach is a topic of fundamental importance to the field of polymer synthesis. Herein, we initially report the coordination-insertion polymerization of para-alkoxystyrene (pAOS) monomers by the dibenzobarrelene-based α-diimine palladium catalysts. The unprecedented polymerization characteristics including rapid initiation, fast chain growth, controlled chain transfer, and high-molecular-weight polymer with a narrow distribution (Mw > 1000 kg/mol, PDI 1.32) reflected previously unrecognized aspects of palladium-catalyzed pAOS polymerization. Chain-end analysis and characterization of palladium intermediates showed that the pAOS monomer was rapidly inserted into the primary palladium species in a full 1,2-regioselectivity, and the chain transfer took place by monomer-assisted β-H abstraction at high monomer concentrations. The resultant polymers showed improved mechanical properties and thermal stabilities and were also attractive candidates of hydrophilic styrenic resin.
Design, synthesis of novel 4,5-dihydroisoxazole-containing benzamide derivatives as highly potent FtsZ inhibitors capable of killing a variety of MDR Staphylococcus aureus
Song, Di,Bi, Fangchao,Zhang, Nan,Qin, Yinhui,Liu, Xingbang,Teng, Yuetai,Ma, Shutao
supporting information, (2020/09/11)
Antibiotic resistance among clinically significant bacterial pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant S. aureus (VRSA) is becoming a prevalent threat to public health, and new antibacterial agents with novel mechanisms of action hence are in an urgent need. As a part of continuing effort to develop antibacterial agents, we rationally designed and synthesized two series of 4,5-dihydroisoxazol-5-yl and 4,5-dihydroisoxazol-3-yl-containing benzamide derivatives that targeted the bacterial cell division protein FtsZ. Evaluation of their activity against a panel of Gram-positive and -negative pathogens revealed that compound A16 possessing the 4,5-dihydroisoxazol-5-yl group showed outstanding antibacterial activity (MIC, ≤0.125–0.5 μg/mL) against various testing strains, including methicillin-resistant, penicillin-resistant and clinical isolated S. aureus strains. Besides, further mouse infection model revealed that A16 could be effective in vivo and non-toxic to Hela cells. Finally, a detailed discussion of structure-activity relationships was conducted, referring to the docking results. It is worth noting that substituting a 4,5-dihydroisoxazole ring for the isoxazole ring not only broadened the antibacterial spectrum but also resulted in a significant increase in antibacterial activity against S. aureus strains. Taken together, these results suggest a promising chemotype for the development of new FtsZ-targeting bactericidal agents.
Electrooxidative 1,2-Bromoesterification of Alkenes with Acids and N-Bromosuccinimide
Wan, Chao,Song, Ren-Jie,Li, Jin-Heng
supporting information, p. 2800 - 2803 (2019/04/30)
A simple three-component 1,2-bromoesterification of alkenes with acids and N-bromosuccinimide under electrochemical oxidative conditions is described. This transformation enables the construction of β-bromoalkyl esters via oxidative C-Br/C-O difunctionalization, where a variety of alkenes, including styrenes and cycloolefins, were well tolerated to react efficiently with a wide range of acids, such as aromatic acids, aliphatic acids, and amino acids.
Coumarin Photocaging Groups Modified with an Electron-Rich Styryl Moiety at the 3-Position: Long-Wavelength Excitation, Rapid Photolysis, and Photobleaching
Lin, Qiuning,Yang, Lipeng,Wang, Zhiqiang,Hua, Yujie,Zhang, Dasheng,Bao, Bingkun,Bao, Chunyan,Gong, Xueqing,Zhu, Linyong
supporting information, p. 3722 - 3726 (2018/03/06)
A new class of coumarin photocaging groups modified with an electron-rich styryl moiety at the 3-position was constructed. The large π-conjugated structure and stabilization of the carbocation intermediates by electron donors endowed the new photocaging groups with excellent long-wavelength absorption, large two-photon absorption cross-sections, and high uncaging quantum yields. Moreover, the new photocaging groups displayed unique photobleaching properties after photocleavage as a result of the intramolecular cyclization rearrangement of a carbocation intermediate to form five-membered ring byproducts and block the styryl conjugation at the 3-position. These superior properties of the new photocaging groups are extremely beneficial for high-concentration samples and thick specimens, thus extending the application of photocaging groups in many fields.
Flow Chemistry Syntheses of Styrenes, Unsymmetrical Stilbenes and Branched Aldehydes
Bourne, Samuel L.,O'Brien, Matthew,Kasinathan, Sivarajan,Koos, Peter,Tolstoy, Paeivi,Hu, Dennis X.,Bates, Roderick W.,Martin, Benjamin,Schenkel, Berthold,Ley, Steven V.
, p. 159 - 172 (2013/03/13)
Two tandem flow chemistry processes have been developed. A single palladium-catalysed Heck reaction with ethylene gas provides an efficient synthesis for functionalised styrenes. Through further elaboration the catalyst becomes multi-functional and performs a second Heck reaction providing a single continuous process for the synthesis of unsymmetrical stilbenes. In addition, the continuous, rhodium-catalysed, hydroformylation of styrene derivatives with syngas affords branched aldehydes with good selectivity. Incorporation of an in-line aqueous wash and liquid-liquid separation allowed for the ethylene Heck reaction to be telescoped into the hydroformylation step such that a single flow synthesis of branched aldehydes directly from aryl iodides was achieved. The tube-in-tube semi-permeable membrane-based gas reactor and liquid-liquid separator both play an essential role in enabling these telescoped flow processes.
Long conjugated 2-nitrobenzyl derivative caged anticancer prodrugs with visible light regulated release: Preparation and functionalizations
Bao, Chunyan,Jin, Ming,Li, Bo,Xu, Yaodong,Jin, Jingyan,Zhu, Linyong
, p. 5238 - 5244 (2012/08/08)
A series of anticancer prodrugs with different chemical functional groups were prepared, in which the styryl conjugated 2-nitrobenzyl derivatives were introduced as the phototrigger to regulate the drug (chlorambucil) release. Compared to the common 4,5-dimethoxy-2-nitrobenzyl caged compounds, most of the prodrugs exhibited large and redshifted one-photon absorption within the visible range. One-photon excitation for the drug release was studied by measuring UV-vis absorption, FT-IR, and HPLC spectra, which suggested that chlorambucil was released effectively and precisely by manipulating external light conditions. And the introduction of different functional groups made this type of prodrug a good platform to further react with some typical drug carriers and to further form excellent visible light responsive drug delivery systems. Moreover, the drug also could be effectively released under the excitation of two-photon at 800 nm with comparable photorelease efficiencies. The Royal Society of Chemistry 2012.
Enhancement of acid photogeneration through a para-to-meta substitution strategy in a sulfonium-based alkoxystilbene designed for two-photon polymerization
Xia, Rongjie,Malval, Jean-Pierre,Jin, Ming,Spangenberg, Arnaud,Wan, Decheng,Pu, Hongting,Vergote, Thomas,Morlet-Savary, Fabrice,Chaumeil, Helene,Baldeck, Patrice,Poizat, Olivier,Soppera, Olivier
experimental part, p. 237 - 244 (2012/05/20)
This contribution reports on the synthesis and the photochemical behavior of two new sulfonium-based photoacid generators (PAGs). We demonstrate that a para-to-meta substitution of a methyl (p-cyanobenzyl) sulfonium group in a 4-alkoxystilbene core strongly influences the photodissociation efficiency of the PAGs and leads to an increase of the quantum yield for acid generation by a factor 2.4. This substantial effect, which was also corroborated by a reactivity enhancement in cationic photopolymerization, is assigned to the modulation of the electronic interaction between two low lying excited states whose energy gap is strongly influenced by this substitution effect. Moreover, it was found that the position of the sulfonium moiety hardly affects the two-photon absorption properties of these push-pull chromophores. By the two-photon fabrication of microstructures, we finally show the potential use of the meta derivative as cationic two-photon initiator.
Styryl conjugated coumarin caged alcohol: Efficient photorelease by either one-photon long wavelength or two-photon NIR excitation
Bao, Chunyan,Fan, Guanshui,Lin, Qiuning,Li, Bo,Cheng, Shuiyu,Huang, Qi,Zhu, Linyong
supporting information; experimental part, p. 572 - 575 (2012/03/26)
The synthesis and photorelease properties of a new phototrigger for alcohols are described. Compared to ester 4 caged by the reported [7-(diethylamino)coumarin-4-yl]methoxycarbonyl (DEACM) phototrigger, the caged ester 3 shows an efficient single-photon photolysis efficiency upon irradiation of long wavelength light (λ = 475 nm) and a stronger two-photon photolysis sensitivity with 800 nm laser light. Its promising properties and the efficient photorelease of adenosine make it very useful as a caging group for biological applications.
