Transition metal catalysis in confined spaces

Leenders, Stefan H. A. M.; Gramage‐Doria, Rafael; Bruin, Bas de; Reek, Joost N. H.

doi:10.1039/c4cs00192c

Cited by 579 publications

(304 citation statements)

References 114 publications

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“…The development of host molecules, supramolecules, and polymers that possess a unique confined nano‐space suitable for encapsulating specific guests has been attracting significant attention1 because of their broad applications toward molecular recognition, sensing, separation1c,1g,1j and catalysis,1h,1k,1l,1o,1p as well as electronic and optoelectronic materials 1d. Cyclic host molecules, such as modified cyclodextrins1a,1g and self‐assembled metal–organic cages1f,1h,1i,1l–1n and organic nanocapsules,1c are among the most extensively investigated host molecules.…”

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confidence: 99%

“Helix‐in‐Helix” Superstructure Formation through Encapsulation of Fullerene‐Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

et al. 2016

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A one‐handed 310‐helical hexapeptide is efficiently encapsulated within the helical cavity of st‐PMMA when a fullerene (C60) derivative is introduced at the C‐terminal end of the peptide. The encapsulation is accompanied by induction of a preferred‐handed helical conformation in the st‐PMMA backbone with the same‐handedness as that of the hexapeptide to form a crystalline st‐PMMA/peptide‐C60 inclusion complex with a unique optically active helix‐in‐helix structure. Although the st‐PMMA is unable to encapsulate the 310‐helical peptide without the terminal C60 unit, the helical hollow space of the st‐PMMA is almost filled by the C60‐bound peptides. This result suggests that the C60 moiety can serve as a versatile molecular carrier of specific molecules and polymers in the helical cavity of the st‐PMMA for the formation of an inclusion complex, thus producing unique supramolecular soft materials that cannot be prepared by other methods.

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confidence: 99%

“Helix‐in‐Helix” Superstructure Formation through Encapsulation of Fullerene‐Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

et al. 2016

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“…The IL support effect can be either geometrical and/or electronic but also as a physical barrier controlling the access or removal of reagents, intermediates and products from the catalytically active site. 9 This process looks like flowing liquid(s) (reagents and products) through a chemically active membrane 10 composed of SILP/NPs in confined space 11,12 (Scheme 1), i.e., a nonequilibrium phenomenon. A principal point of this nonequilibrium is that all the chemical transformations as well as the other physico-chemical phenomena occurring with a catalyst in the course of its operation have to be considered as being inherently linked to the main "coupling" reaction.…”

Section: Introductionmentioning

confidence: 99%

Catalytically Active Membranelike Devices: Ionic Liquid Hybrid Organosilicas Decorated with Palladium Nanoparticles

et al. 2016

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Ionic liquid (IL)-hybrid organosilicas based on 1-n-butyl-3-(3-trimethoxysilylpropyl)-imidazolium cations associated with hydrophilic and hydrophobic anions decorated with well dispersed and similar sized (1.8-2.1 nm) Pd nanoparticles (PdNPs) are amongst the most active and selective catalysts for the partial hydrogenation of conjugated dienes to monoenes. The location of the sputter-imprinted Pd-NPs on different supports, as determined by RBS and HS-LEIS analysis, is modulated by the strength of the contact ion pair formed between the imidazolium cation and the anion, rather than the IL-hybrid organosilica pore size and surface area. In contrast, the pore diameter and surface area of the hybrid supports display a direct correlation with the anion hydrophobicity. XPS analysis showed that the Pd(0) surface component decreases with increasing ionic bond strength between the imidazolium cation and the anions (contact ion pair). The finding is corroborated by changes in the coordination number associated with the Pd-Pd scattering in EXAFS measurements. Hence, the interaction of the IL with the metal surface is found to occur via IL contact pairs (or aggregates). The observed selectivities of ≥99% to monoenes at full diene conversion indicate that the selectivity is intrinsic to the electron deficient Pd-metallic surfaces in this "restricted" ionic environment. This suggests that ILhybrid organosilica/Pd-NPs under multiphase conditions ("dynamic asymmetric mixture") operate akin to catalytically active membranes, i.e. far from the thermodynamic equilibrium. Detailed kinetic investigations show that the reaction rate is zero-order with respect to hydrogen and dependent on the fraction of catalyst surfaces covered by either the substrate and/or the product. The reaction proceeds via rapid inclusion and sorption of the diene to the IL/Pd metal surface saturated with H species. This is followed by reversible hydride migration to generate a π-allyl intermediate. The reductive elimination of this intermediate, the formal ratedetermining step (RDS), generates the alkene that is rapidly expelled from the IL phase to the organic phase.

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“…[1～4] 、材料 [5,6] [16,17] 、生物医药 [18,19] 等众多领域具有广泛的应用, 显示出巨大的发展潜力. 唑类化合物是一类重要而特殊的杂环, 包括五元唑杂环(如咪唑类 [20] 、吡唑类 [21] 、噻唑类 [22] 、噁唑类 [23] 、三唑类 [24,25] 、四唑类 [26] 等)及其稠合唑杂环(如苯并噻唑类 [27] 、苯并咪唑类 [28,29] 、苯并三唑类 [30] 、咔唑类 [31,32] 等), 含有氮、氧和/或硫等多个杂原子, 具有芳香性和丰富的电子, 这种奇特结构不仅易通过多种非共价键力如配位键、氢键、范德华力、π-π 堆积、疏水与静电作用等多种非共价键…”

Section: 超分子化学是一个高度交叉的活跃研究领域在化学unclassified

Current Researches and Applications of Azole-BasedSupermolecules as Medicinal Agents

Cheng¹,

Wang²,

Addla³

et al. 2016

Chin. J. Org. Chem.

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Noncovalent bond forces-based supramolecular chemistry grows quite rapidly and has been revealed to have extensively potential applications and huge development values in chemistry, physics, materials and information science, medicine and so on. Azole compounds such as imidazoles, thiazoles, oxazoles, pyrazoles, triazoles, tetrazoles and carbazoles containing special nitrogen aromatic heterocyclic structure, can exert non-covalent forces to form supramolecular complexes with inorganic and/or organic compounds and exhibit broad biological activity. In recent years, heterocyclic azole-based supramolecular complexes have been expeditiously expanding in the field of medicine, and have become a quite hot topic. Combined with our work and referring to other literature in recent 5 years, this paper systematically reviews the researches and applications of azole-based supermolecules as medicinal agents including anticancer, antibacterial, antifungal, antiparasitic, antidiabetic, antihypertensive, anti-inflammatory drugs and other ones. Finally, the perspectives of the future development of azole-based supermolecules as medicinal agents are also presented.

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Transition metal catalysis in confined spaces

Cited by 579 publications

References 114 publications

“Helix‐in‐Helix” Superstructure Formation through Encapsulation of Fullerene‐Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

“Helix‐in‐Helix” Superstructure Formation through Encapsulation of Fullerene‐Bound Helical Peptides within a Helical Poly(methyl methacrylate) Cavity

Catalytically Active Membranelike Devices: Ionic Liquid Hybrid Organosilicas Decorated with Palladium Nanoparticles

Current Researches and Applications of Azole-BasedSupermolecules as Medicinal Agents

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