Biphasic aqueous organometallic catalysis promoted by cyclodextrins: Can surface tension measurements explain the efficiency of chemically modified cyclodextrins?

Rhodium Complexes Non‐Covalently Bound to Cyclodextrins: Novel Water‐Soluble Supramolecular Catalysts for the Biphasic Hydroformylation of Higher Olefins

“…Furthermore, tensiometric measurements indicated that this cationic CD adsorbs weakly at the liquid-liquid interface, which is unfavourable to the mass-transfer between the aqueous and organic phases. [11] The aldehyde selectivity in the presence of mono-HTMAP-a-CD was similar to that observed with the non-charged CD derivatives, confirming the protective effect of the CD cavity towards the isomerisation reaction. Indeed, when the olefin is inside the hydrophobic host cavity of the a-CD, the formation of isomerising species leading to internal olefins by b-hydride elimination is prohibited by the steric hindrance.…”

“…As methylation of CD enhances the surface active properties [11] of CD and its affinity [12] for long-chain olefins, we envisaged the synthesis of methylated derivatives of the mono-HTMAP-a-CD and the tetra-HTMAP-a-CD. Initial attempts by adding 2,3-epoxypropyltrimethylammonium chloride to randomly methylated-a-CD (RAME-a-CD) in aqueous basic medium, or in N,N-dimethylformamide containing barium oxide and barium hydroxide, failed due to the poor reactivity of the hydroxy groups of the RAME-a-CD.…”

From Zeolite to Host-Guest Nanocomposite Materials

“…3 represents TEM images of -Cyclodextrin capped Au nanoparticles [16]. Other important applications of CDs involve: supramolecular carrier in organometallic reactions [17] and pharmaceutical applications for drug release [18,19]. To produce HPLC columns allowing chiral enantiomers separation, -cyclodextrins are used [20].…”

Reuse of Cyclodextrin Glycosyltransferase through Immobilization on Magnetic Carriers

“…The most common CDs have six (α-CD), seven (β-CD) and eight (γ-CD) glucose units forming the cone shaped structure, that is able to accommodate hydrophobic molecules within is interior, the diameter of which is approximately 5.2 A˚ (α-CD), 6.6 A˚ (β-CD), and 8.4 A˚ (γ-CD) [1]. Externally, the structure is sufficiently hydrophilic to make CDs water soluble [2]. These cyclic glucose polymers are used in the pharmaceutical, cosmetic and food industries [3].…”