66888-72-0Relevant articles and documents
Activation of Aptamers with Gain of Function by Small-Molecule-Clipping of Intramolecular Motifs
Huang, Mengjiao,Li, Tingyu,Xu, Yuanfeng,Wei, Xinyu,Song, Jia,Lin, Bingqian,Zhu, Zhi,Song, Yanling,Yang, Chaoyong
supporting information, p. 6021 - 6028 (2021/01/29)
Click reactions have the advantages of high reactivity, excellent orthogonality, and synthetic accessibility. Inspired by click reactions, we propose the concept of “clipped aptamers”, whose binding affinity is regulated by the “clip”-like specific intera
Pd(OAc)2 immobilized on imine-functionalized microporous covalent triazine polymer as efficient heterogeneous catalyst for Mizoroki–Heck cross-coupling reaction
Sadhasivam, Velu,Mathappan, Mariyappan,Harikrishnan, Muniyasamy,Chithiraikumar, Chinnadurai,Murugesan, Sepperumal,Siva, Ayyanar
, p. 2853 - 2866 (2018/02/16)
A template consisting of Pd(OAc)2 immobilized on imine-functionalized microporous covalent triazine polymer network (Pd/TATAE) was synthesized and found to be an efficient and recyclable heterogeneous solid catalyst for Mizoroki–Heck C–C coupling of styrene with substituted aryl halides under mild reaction conditions and without addition of any ligand or additives. Furthermore, Pd/TATAE could be recycled for nine consecutive cycles with minor loss of catalytic activity. Finally, the Pd/TATAE catalyst showed good catalytic activity with excellent yield of 96?% and high turnover number of 3349.
Ultrasonic assisted dimeric cinchona based chiral phase transfer catalysts for highly enanatioselective synthesis of epoxidation of α,β-unsaturated ketones
Sivamani, Jayaraman,Ashokkumar, Veeramanoharan,Sadhasivam, Velu,Duraimurugan, Kumaraguru,Siva, Ayyanar
, p. 60293 - 60299 (2015/02/19)
New types of bis-quaternary ammonium bromide as chiral multisite phase transfer catalysts derived from cinchona alkaloids have been developed and evaluated for the enantioselective epoxidation of chalcones in the presence of lower concentrations of various oxidants, bases and ultrasonic irradiation conditions. Under optimized conditions, excellent chemical yields of up to 98% along with the highest enantioselectivities of about 98% were obtained by using the reported catalysts.
Light-controlled macrocyclization of tetrathiafulvalene with azobenzene: Designing an optoelectronic molecular switch
Azov, Vladimir A.,Cordes, Jens,Schlüter, Dirk,Dülcks, Thomas,B?ckmann, Marcus,Doltsinis, Nikos L.
, p. 11714 - 11721 (2015/02/19)
Macrocyclization between tetrathiafulvalene (TTF) dithiolates and bis-bromomethylazobenzenes/bis-bromomethylstilbenes is investigated under high dilution conditions. We show that macrocycles of different size can be formed depending on whether the (Z)- or (E)-isomers of azobenzene (AB) or stilbene are used. This represents the first example of a light-controllable cyclization reaction. The oxidation potential of the small, structurally rigid TTF-AB macrocycle is found to depend on the conformation of the AB moiety, opening the way for the modulation of redox properties by an optical stimulus. DFT calculations show that the out-of-plane distortion of the TTF moiety in this macrocycle is responsible for the variation of its oxidation potential upon photoisomerization of the neighboring AB bridge.
Homodimeric bis-quaternary heterocyclic ammonium salts as potent acetyl- and butyrylcholinesterase inhibitors: A systematic investigation of the influence of linker and cationic heads over affinity and selectivity
Conejo-García, Ana,Pisani, Leonardo,Del Carmen Nú?ez, Maria,Catto, Marco,Nicolotti, Orazio,Leonetti, Francesco,Campos, Joaquín M.,Gallo, Miguel A.,Espinosa, Antonio,Carotti, Angelo
body text, p. 2627 - 2645 (2011/06/21)
A molecular library of quaternary ammonium salts (QASs), mainly composed of symmetrical bis-quaternary heterocyclic bromides exhibiting choline kinase (ChoK) inhibitory activity, were evaluated for their ability to inhibit acetyl- and butyrylcholinesterase (AChE and BChE, respectively). The molecular framework of QASs consisted of two positively charged heteroaromatic (pyridinium or quinolinium) or sterically hindered aliphatic (quinuclidinium) nitrogen rings kept at an appropriate distance by lipophilic rigid or semirigid linkers. Many homodimeric QASs showed AChE and BChE inhibitory potency in the nanomolar range along with a low enzymatic selectivity. Computational studies on AChE, BChE, and ChoK allowed identification of the key molecular determinants for high affinity and selectivity over either one of the three enzymes and guided the design of a hybrid bis-QAS (56) exhibiting the highest AChE affinity (IC50 = 15 nM) and selectivity over BChE and ChoK (SI = 50 and 562, respectively) and a promising pharmacological potential in myasthenia gravis and neuromuscular blockade.
Modification of the optoelectronic properties of membranes via insertion of amphiphilic phenylenevinylene oligoelectrolytes
Garner, Logan E.,Park, Juhyun,Dyar, Scott M.,Chworos, Arkadiusz,Sumner, James J.,Bazan, Guillermo C.
scheme or table, p. 10042 - 10052 (2010/10/03)
We report on the modification of membranes by incorporation of phenylenevinylene oligoelectrolytes with the goal of tailoring their optical and electronic properties and their applications. A watersoluble distyrylstilbene oligoelectrolyte (DSSN+), capped
Control of the intramolecular [2+2] photocycloaddition in a bis-stilbene macrocycle
Xu, Yuewen,Smith, Mark D.,Krause, Jeanette A.,Shimizu, Linda S.
supporting information; experimental part, p. 4874 - 4877 (2009/09/30)
(Chemical Equation Presented) The intramolecular [2+2] photocyclization of a bis-stilbene macrocycle was studied. The reaction can be controlled by the insertion and removal of urea protecting groups. Upon UV-irradiation in both the solid state and DMSO s
Preparation and photochemistry of dendrimers with isolated stilbene chromophores
Soomro, Shahid A.,Benmouna, Reda,Berger, Ruediger,Meier, Herbert
, p. 3586 - 3593 (2007/10/03)
In addition to the model compounds 4a and 4b, the dendrimers 11 and 14 with trans-stilbene chromophores in the core and on the periphery of the dendrons were prepared and their photochemistry was studied in solution and in neat films. Due to the flexibili
Synthesis and structure of 4,4′-bis(2,3,4,5,6-pentafluorostyryl)stilbene, a self-assembling J aggregate based on aryl-fluoroaryl interactions
Feast,Loevenich,Puschmann,Taliani
, p. 505 - 506 (2007/10/03)
The synthesis and characterisation of 4,4′-bis(2,3,4,5,6-pentafluorostyryl)stilbene is described; this molecule forms a J aggregate by self-assembly based on aryl-fluoroaryl interactions.
Synthesis, molecular modeling, and K+ channel-blocking activity of dequalinium analogues having semirigid linkers
Rosa, Joaquin Campos,Galanakis, Dimitrios,Ganellin, C. Robin,Dunn, Philip M.
, p. 4247 - 4254 (2007/10/03)
Dequalinium [1,1'-(decane-l,10-diyl)bis(2-methyl-4-aminoquinolinium)] is an effective blocker of the small conductance Ca2+activated K+ channel. It has been shown that the number of methylene groups in the alkyl chain linking the two quinolinium rings of this type of molecule is not critical for activity. To further investigate the role of the linker, analogues of dequalinium have been synthesized, in which the alkyl chain has been replaced by CH2XCH2 where X is a rigid or semirigid group containing aromatic rings. The compounds have been tested for blockade of the slow after- hyperpolarization on rat sympathetic neurons. The most potent compounds have X = phenanthryl, fluorenyl, cis-stilbene, and C6H4(CH2)(n)C6H4 where n = 0-4. The conformational preferences of the compounds were investigated using the XED/COSMIC molecular modeling system. Although there is some dependence of the potency of the analogue on the conformational properties of the linker (X), overall, X groups having substantial structural differences are tolerated. It seems that X provides a support for the two quinolinium groups and does not interact with the channel directly. The intramolecular separation between the quinolinium rings, which is provided by rigid groups X, is not critical for activity; this may be attributed to the residual conformational mobility of the heterocycles and to the extensive delocalization of the positive charge. These two factors may permit favorable contacts between the quinolinium groups and the channel over a range of intramolecular separations.
