Synthetic Application of Cyclodextrins in Combination with Metal Ions, Complexes, and Metal Particles

Abstract

Cyclodextrins are green, environmentally benign products available through the enzymatic degradation of starch for a multitude of varied applications. This review attempts to collect useful information with respect to catalytic studies performed with the use of cyclodextrin and modified cyclodextrin preparations applied in combination of or loaded with varied catalytically active species including metal ions, complexes, and metal particles. Major sections are about their use in hydrogenation, reduction, oxidation, hydroformylation and coupling reactions. Additional sections include their utilization in ring formation and ring opening as well as degradation of pollutants. In the last part, examples about ester hydrolysis, hydroboration and hydrosilylation, as well as hydrogen production are treated. Data collected and analyzed indicate the importance and high potential of cyclodextrin-based catalysts in sustainable chemistry.

Synthesis of Mono-Amino Substituted γ-CD: Host–Guest Complexation and In Vitro Cytotoxicity Investigation

“…In particular, the hydrophobic cavity of CDs enables them to encapsulate hydrophobic molecules of suitable sizes and generate inclusion complexes [ 4 ], which is called host–guest complexation [ 5 ]. This remarkable property of encapsulation of guest molecules is applied in many fields, including medicine, materials science, food, and agricultural industries [ 6 , 7 , 8 , 9 ]. The natural β-CD is the most commonly used CD in industrial products.…”

An atomistic view on the uptake of aromatic compounds by cyclodextrin immobilized on mesoporous silica

“…Their hydrophilic outer surface renders them soluble in water, while the hydrophobic interior can accommodate hydrophobic compounds. Therefore, they are employed in the removal of pollutants from aqueous media [1,2], as chiral selectors [3] or in (asymmetric) supramolecular catalysis [4][5][6][7][8][9][10] among many other fields of applications including the use of cyclodextrins as drug delivery agents or as building blocks in the design of dynamic and adaptive materials [11,12]. By tuning the size and shape of the hydrophobic cavity through derivatization of the native cyclodextrins the selectivity towards the target compounds can be increased [13].…”

Cu2O−CD nanosuperstructures as a Biomimetic Catalyst for Oxidation of Benzylic sp3 C−H bonds and Secondary Amines using Molecular Oxygen: First Total Synthesis of proposed Swerilactone O

“…This novel protocol provides facile access to a diverse array of fascinating nanoforms of metal‐supramolecular nanosuperstructures which are proven to show good catalytic activity for propargyl amination reaction. Additionally, this protocol utilizes cyclodextrins that are inexpensive, benign, cyclic oligosaccharides that are known to show host‐guest interactions and are recently explored to synthesize interesting structural motifs/complexes involving metals and nanoparticles [52–56] . Developing such self‐assembled metal‐supramolecular nanosuperstructures is an upcoming area of research owing to several advantages such as ease of synthesis using simple, benign, and inexpensive starting materials under mild reaction conditions [57–61] .…”

“…Additionally, this protocol utilizes cyclodextrins that are inexpensive, benign, cyclic oligosaccharides that are known to show host-guest interactions and are recently explored to synthesize interesting structural motifs/ complexes involving metals and nanoparticles. [52][53][54][55][56] Developing such self-assembled metal-supramolecular nanosuperstructures is an upcoming area of research owing to several advantages such as ease of synthesis using simple, benign, and inexpensive starting materials under mild reaction conditions. [57][58][59][60][61] Henceforth, with a view to amalgamate the use of green oxidant molecular oxygen and heterogeneous copper catalysis, in this work, we demonstrate the combination of molecular oxygen and Cu 2 OÀ CD nanosuperstructures along with co-oxidant NHPI as a sustainable, heterogeneous catalytic system for the oxidation of benzylic substrates and secondary amines.…”