221648-03-9Relevant academic research and scientific papers
Base- A nd Catalyst-Induced Orthogonal Site Selectivities in Acylation of Amphiphilic Diols
Ashush, Natali,Dobrovetsky, Roman,Fallek, Amit,Fallek, Reut,Portnoy, Moshe
supporting information, (2020/05/25)
Seeking to selectively functionalize natural and synthetic amphiphiles, we explored acylation of model amphiphilic diols. The use of a nucleophilic catalyst enabled a remarkable shift of the site selectivity from the polar site, preferred in background noncatalyzed or base-promoted reactions, to the apolar site. This tendency was significantly enhanced for organocatalysts comprising an imidazole active site surrounded by long/branched tails. An explanation of these orthogonal modes of selectivity is supported by competitive experiments with monoalcohol substrates.
Effect of dendrimer generation and aglyconic linkers on the binding properties of mannosylated dendrimers prepared by a combined convergent and onion peel approach
Sehad, Celia,Shiao, Tze Chieh,Sallam, Lamyaa M.,Azzouz, Abdelkrim,Roy, René
, (2018/08/17)
An efficient study of carbohydrate-protein interactions was achieved using multivalent glycodendrimer library. Different dendrimers with varied peripheral sugar densities and linkers provided an arsenal of potential novel therapeutic agents that could be
Chemoselectivity Improvement via Partial Shielding of an Imidazole Active Site in Branched/Dendritic Homogeneous Catalysts of the Baylis–Hillman Reaction
Karabline-Kuks, Jeny,Ramesh, Palakuri,Portnoy, Moshe
, p. 3541 - 3554 (2016/11/25)
While comparing analogous polystyrene-supported and homogeneous catalysts for the Baylis–Hillman reaction, we hypothesized that the hydrophobic envelopment of the imidazole catalytic sites of the former is responsible for the significantly better chemoselectivity exhibited by the heterogeneous catalysts compared to their homogeneous counterparts. In order to test this hypothesis, we prepared a series of branched/dendritic homogeneous catalysts, with an imidazole active site near the focal point and flexible tails of various lengths and polarities, capable of providing partial shielding of this site. The design of the catalysts was based on a 5-hydroxyisophthalate scaffold, and they were prepared through a number of multistep synthetic pathways. The comparison of the catalysts under a variety of conditions in a model Baylis–Hillman reaction demonstrated that long hydrophobic tales enhance the chemoselectivity parameter of the catalysis, while reducing the rate of the consumption of the substrates, and that the chemoselectivity is further improved by the presence of a free phenolic moiety in the vicinity of the catalytic imidazole unit. Moreover, in second-generation catalysts, the peripheral long tails could be either hydrophobic or polar, since the dendritic inner backbone itself presumably partially provides the necessary isolation of the catalytic site. Thus, experimental results support our hypothesis. (Figure presented.).
Halogen-bonding for visual chloride ion sensing: A case study using supramolecular poly(aryl ether) dendritic organogel systems
Liu, Zhi-Xiong,Sun, Yihua,Feng, Yu,Chen, Hui,He, Yan-Mei,Fan, Qing-Hua
supporting information, p. 2269 - 2272 (2016/02/18)
A convenient and straightforward method for the visual recognition of chloride ion has been established through a chloride-responsive dendritic organogel. The specificity was largely attributed to the higher binding affinity of the dendritic gelator for c
A systematic study of peripherally multiple aromatic ester-functionalized poly(benzyl ether) dendrons for the fabrication of organogels: Structure-property relationships and thixotropic property
Feng, Yu,Liu, Zhi-Xiong,Chen, Hui,Yan, Zhi-Chao,He, Yan-Mei,Liu, Chen-Yang,Fan, Qing-Hua
supporting information, p. 7069 - 7082 (2014/06/09)
A new class of peripherally multiple aromatic ester-functionalized poly(benzyl ether) dendrons and/or dendrimers with different focal point substituents, surface groups, interior structures, as well as different generations have been synthesized and their structure-property relationships with respect to their gelation ability have been investigated systematically. Most of these dendrons are able to gel organic solvents over a wide polarity range. Evident dendritic effects were observed not only in gelation capability but also in thermotropic, morphological, and rheological characterizations. It was disclosed that subtle changes in peripheral ester functionalities and interior dendritic structures affected the gelation behavior of the dendrons significantly. Among all the dendrons studied, the second- and third-generation dendrons G0G2-Me and G0G3-Me with dimethyl isophthalates (DMIP) as peripheral groups exhibited the best capability in gelation, and stable gels were formed in more than 22 aromatic and polar organic solvents. The lowest critical gelation concentration (CGC) reached 2.0 mg mL-1, indicating that approximately 1.35×104 solvent molecules could be entrapped by one dendritic molecule. Further study on driving forces in gel formation was carried out by using a combination of single-crystal/powder X-ray diffraction (XRD) analysis and concentration- dependent (CD)/temperature-dependent (TD) 1H NMR spectroscopy. The results obtained from these experiments revealed that the multiple π-π stacking of extended π-systems due to the peripheral DMIP rings, cooperatively assisted by non-conventional hydrogen-bonding, is the key contributor in the formation of the highly ordered supramolecular and fibrillar network. In addition, these dendritic organogels exhibited unexpected thixotropic-responsive properties, which make them promising candidates with potential applications in the field of intelligent soft materials. s
Peripherally dimethyl isophthalate-functionalized poly(benzyl ether) dendrons: A new kind of unprecedented highly efficient organogelators
Feng, Yu,Liu, Zi-Tong,Liu, Ji,He, Yan-Mei,Zheng, Qi-Yu,Fan, Qing-Hua
supporting information; experimental part, p. 7950 - 7951 (2009/12/02)
(Figure Presented) A series of poly(benzyl ether) dendrons, up to the fourth generation, decorated in their periphery with dimethyl esters were divergently synthesized and fully characterized. These dendrons were found to be unprecedented highly efficient
Molecular recognition abilities of a new class of water-soluble cyclophanes capable of encompassing a neutral cavity
Inouye, Masahiko,Fujimoto, Kazuhisa,Furusyo, Masaru,Nakazumi, Hiroyuki
, p. 1452 - 1458 (2007/10/03)
We developed a new class of water-soluble cyclophanes, pyrenophanes, capable of encompassing a neutral cavity, in which the hydrophobic area is constructed by aligning two flat polynuclear aromatic rings parallel at an appropriate space that could interpo
