Urea Derivatives as Functional Molecules: Supramolecular Capsules, Supramolecular Polymers, Supramolecular Gels, Artificial Hosts, and Catalysts

Yokoya, Masashi; Kimura, Shinya; Yamanaka, Masamichi

doi:10.1002/chem.202004367

Cited by 77 publications

(53 citation statements)

References 201 publications

(341 reference statements)

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“…The introduction of one or more hydrogen bonding functional group is a typical strategy in LMWG design. A ureido group is a hydrogen bonding functional group commonly found in LMWGs, and many urea derivatives have been reported as LMWGs [15,16] . Urea derivatives, which form ideal intermolecular hydrogen bonds, require only simple structural modifications to function as LMWGs [17–21] .…”

Section: Introductionmentioning

confidence: 99%

Effect of Alkyl Chain Length of N‐Alkyl‐N′‐(2‐benzylphenyl)ureas on Gelation

Komiyama

Harada

Hase

et al. 2021

Chemistry An Asian Journal

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Urea derivatives that were substituted with a 2‐benzylphenyl group and an alkyl group functioned as low molecular weight gelators for various organic solvents and ionic liquids. Urea derivatives with long alkyl chains were effective for the gelation of polar solvents. However, they were not suitable for the gelation of non‐polar solvents, whereas urea derivatives with short alkyl chains were effective. Ionic liquids were similar to polar solvents in that urea derivatives with long alkyl chains were the most effective gelators. The physical properties of the formed supramolecular gels were analyzed by dynamic viscoelasticity measurements using a rheometer.

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Section: Introductionmentioning

confidence: 99%

Effect of Alkyl Chain Length of N‐Alkyl‐N′‐(2‐benzylphenyl)ureas on Gelation

Komiyama

Harada

Hase

et al. 2021

Chemistry An Asian Journal

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“…That is, with an increase in the chain of a substituent in urea derivatives, their reactivity in sulfation reactions with sulfamic acid decreases. The reactivity of urea and its derivatives can also be associated with a change in the content of hydrogen bonds [45][46][47].…”

Section: The Role Of the Activator In The Process Of Sulfation Of Xanthan With Sulfamic Acidmentioning

confidence: 99%

Food Xanthan Polysaccharide Sulfation Process with Sulfamic Acid

Kazachenko

Vasilieva

Borovkova

et al. 2021

Foods

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Xanthan is an important polysaccharide with many beneficial properties. Sulfated xanthan derivatives have anticoagulant and antithrombotic activity. This work proposes a new method for the synthesis of xanthan sulfates using sulfamic acid. Various N-substituted ureas have been investigated as process activators. It was found that urea has the greatest activating ability. BBD of xanthan sulfation process with sulfamic acid in 1,4-dioxane has been carried out. It was shown that the optimal conditions for the sulfation of xanthan (13.1 wt% sulfur content) are: the amount of sulfating complex per 1 g of xanthan is 3.5 mmol, temperature 90 °C, duration 2.3 h. Sulfated xanthan with the maximum sulfur content was analyzed by physicochemical methods. Thus, in the FTIR spectrum of xanthan sulfate, in comparison with the initial xanthanum, absorption bands appear at 1247 cm−1, which corresponds to the vibrations of the sulfate group. It was shown by GPC chromatography that the starting xanthan gum has a bimodal molecular weight distribution of particles, including a high molecular weight fraction with Mw > 1000 kDa and an LMW fraction with Mw < 600 kDa. It was found that the Mw of sulfated xanthan gum has a lower value (~612 kDa) in comparison with the original xanthan gum, and a narrower molecular weight distribution and is characterized by lower PD values. It was shown by thermal analysis that the main decomposition of xanthan sulfate, in contrast to the initial xanthan, occurs in two stages. The DTG curve has two pronounced peaks, with maxima at 226 and 286 °C.

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“…27 Ding et al demonstrated the modulation of protein adsorption, vascular cell selectivity and platelet adhesion by multifunctionality of the poly(dopamine) (PDA) coating for vascular stent applications. 28 Recently, urea derivatives have been shown to be excellent functional groups that facilitate interesting performance in terms of biomimetics to biomolecules, 29 tailorable hydrophilicity and hydrogen bonding, 30 etc. These derivatives impart a structure similar to peptide bonds that could have a better chance of binding to protein molecules and enhancing bioactivity.…”

Section: Introductionmentioning

confidence: 99%