Functionalized hollow double-shelled polymeric nano-bowls as effective heterogeneous organocatalysts for enhanced catalytic activity in asymmetric Michael addition

Zhao, Zhiwei; Feng, Dandan; Xie, Guangxin; Ma, Xuebing

doi:10.1016/j.jcat.2017.12.019

Cited by 34 publications

(9 citation statements)

References 60 publications

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“…Michael addition is also a classical and important reaction, and the abundant products attract interest of researchers due to their great commercial value. Numerous supported catalysts modified on laponite, cellulose ionomer, polymeric nanomaterials, and so forth have been developed to promote Michael addition. There are some advantages of mild reaction condition and good recycle ability of these supported catalysts, however, the problems of toxic solvents and long reaction time are still not solved.…”

Section: Results and Discussionmentioning

confidence: 99%

Quaternary Ammonium-Based Functionalized Polyacrylonitrile Fibers with Polarity Tunable Inner Surface Microenvironment for C–C Bond Forming Reactions under Continuous Flow Conditions

Wang

Xiao

et al. 2019

Ind. Eng. Chem. Res.

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A series of quaternary ammonium-based (QAB) functionalized polyacrylonitrile fibers as superbase catalysts for CC bond forming reactions in water were prepared. Alkyl with different chain lengths and benzyl were used to tune the hydrophobicity/hydrophilicity and polarity of the inner surface microenvironment of the QAB functionalized fiber catalysts, and the different microenvironment and the active site synergistically promote the completion of the reaction. The mechanism of the influence of different hydrophilic/hydrophobic catalysts on catalytic activity was proposed. The quaternary ammonium-based functionalized fibers with eight carbon alkyl chains (PANQAB‑8F) as the optimal catalyst performed excellently in green water solvent with specific advantages of low catalyst dosage, mild conditions, high efficiency, and extensive substrate adaptation. Furthermore, the PANQAB‑8F catalyst is very suitable for the continuous flow process, and more than 86% yield was obtained even after the continuous reaction for 160 h; the fiber can be recovered easily and recycled more than 10 times in the continuous-flow system.

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Section: Results and Discussionmentioning

confidence: 99%

Quaternary Ammonium-Based Functionalized Polyacrylonitrile Fibers with Polarity Tunable Inner Surface Microenvironment for C–C Bond Forming Reactions under Continuous Flow Conditions

Wang

Xiao

et al. 2019

Ind. Eng. Chem. Res.

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“…Very recently, the hollow material also has attracted extensive attention on account of its large surface area and low density compared with the other solid materials, and this distinctive structure makes it present some significant application prospects in catalysis, [10] energy, separation, purification, [11,12] and the drug sustained and controlled release. [13] In combination with the hollow material and the MIT, some shortcomings of MIP including the slow mass transfer and the poor selectivity could be solved.…”

Section: Introductionmentioning

confidence: 99%

Preparation and Properties of Hollow Magnetic Liquid Crystal Molecularly Imprinted Polymers as Silybin Sustained‐release Carriers

Tan

Chen

et al. 2021

ChemistrySelect

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In this work, a new drug carrier, the hollow magnetic silybin liquid crystal molecular imprinted polymer (HMS@LC-MIP) was prepared through the reverse atom radical transfer polymerization(RATRP) method. In order to decrease the degree of cross-linker, the liquid crystal ingredient methylphenyl dicyclohexyl ethylene, a kind of physical cross-linker, being able to replace the chemical cross-linker partly, was introduced into the synthetic system. The characterizations of HMS@LC-MIPs were investigated by FT-IR, VSM, TEM and so on. A series of adsorption experiments showed the maximum adsorption capacity and the adsorption equilibrium time of HMS@LC-MIP were 18.53 mg g À 1 and 180 min, respectively, and the relative selectivity factor β = 2.06 implied HMS@LC-MIP had the high selectivity to the template. The in-vitro release experiments exhibited HMS@LC-MIP possessed the good responsiveness to pH values and the desirable slow release performance with 48 h of sustaining time. In short, the HMS@LC-MIP should be of a potential as drug sustained-release agent in the future.

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“…The nanobowls are then obtained by the removal of the immiscible liquid. In the third technique, nanobowls are obtained from collapsed vesicles, which are formed on either soft templates (immiscible liquid droplets) or hard templates (sacrificial nanospheres). − Inspired by the formation of liposomes, the addition of water to colloidal solutions of amphiphilic copolymers has also been demonstrated to produce nanobowls. − The evaporation of the organic solvent from the colloidal nanoparticles results in the “collapse” of the particles into a bowl shape. Nanobowls can also be prepared through lyophilization.…”

Section: Introductionmentioning

confidence: 99%

Bowl-Shaped Polydopamine Nanocapsules: Control of Morphology via Template-Free Synthesis

Sun

Davis

2020

Langmuir

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Synthesis of hollow polydopamine bowl-shaped nanoparticles (nanobowls), as small as 80 nm in diameter, via a one-pot template-free rapid method is reported. Addition of dopamine to a solution of 0.606 mg/mL tris(hydroxymethyl)aminomethane in an ethanol/water mixed solvent resulted in the formation of hollow spherical nanocapsules within 2 h. At longer reaction times, the formation of conventional solid nanospheres dominated the reaction. The wall thickness of the nanocapsules increased with increasing dopamine concentration in the reaction medium. Wall thickness was also influenced by oxygen availability during the reaction. Nanocapsules with thin walls were prone to collapse. When dried, over 90% of the nanocapsules with wall thickness on the order of 11 nm collapsed. Also, the degree of collapse of individual nanoparticles changed from complete to partial to no collapse as the wall thickness was increased. Varying the ethanol content affected the cavity size and overall dimension of the nanocapsules produced but did not result in a significant change to the wall thickness. A mechanism describing the formation of the nanocapsules and their subsequent collapse into nanobowls is presented. The shape-tunable nanobowls prepared through this green, rapid, and affordable method are expected to have applications in the biomedical, electrochemical, and catalytic fields.

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Functionalized hollow double-shelled polymeric nano-bowls as effective heterogeneous organocatalysts for enhanced catalytic activity in asymmetric Michael addition

Cited by 34 publications

References 60 publications

Quaternary Ammonium-Based Functionalized Polyacrylonitrile Fibers with Polarity Tunable Inner Surface Microenvironment for C–C Bond Forming Reactions under Continuous Flow Conditions

Quaternary Ammonium-Based Functionalized Polyacrylonitrile Fibers with Polarity Tunable Inner Surface Microenvironment for C–C Bond Forming Reactions under Continuous Flow Conditions

Preparation and Properties of Hollow Magnetic Liquid Crystal Molecularly Imprinted Polymers as Silybin Sustained‐release Carriers

Bowl-Shaped Polydopamine Nanocapsules: Control of Morphology via Template-Free Synthesis

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