Continuous Production of Bifunctional Platform Chemicals From Plant Oils in Water by Cyclodextrin-Mediated Hydroformylation

Today's cyclodextrin,

today’s cyclodextrin:
CDs supporting the synthesis of renewable chemicals

Cyclodextrin-mediated aqueous biphasic systems are a potent way to recycle homogeneous catalysts, also applicable to producing highly demanded renewable chemical intermediates.

Thomas Seidensticker and his team from TU Dortmund University present the Rh-catalyzed, cyclodextrin-mediated, aqueous biphasic hydroformylation of methyl 10-undecenoate (from castor oil) and methyl 9-decenoate (from rapeseed oil) to produce methyl 12-oxododecanoate and methyl 11-oxoundecanoate, respectively, with high yields and productivity.

Direct Continuous Flow Synthesis of Two Difficult Polypeptides Using β-Cyclodextrins

Today's cyclodextrin,

Direct Continuous Flow Synthesis of Two Difficult Polypeptides Using β-Cyclodextrins

Wonderful paper from Hungary by Szaniszló Szebasztián, Gitta Schlosser, Viktor Farkas and Perczel András

Results show that the use of β-CyD as an additive results in a significant (8–19%) increase in the purity of the crude polypeptide compared to that determined by our reference method.

Direct Continuous Flow Synthesis of Two Difficult Polypeptides Using β-Cyclodextrins | The Journal of Organic Chemistry

The role of cyclodextrins in the acceleration of the reaction rate in a biphasic hydroformylations

Today's cyclodextrin,

Today’s cyclodextrin is some nice, CD-supported chemistry.

Highlights
• Cyclodextrins assist water-based biphasic hydroformylation.
• Examined for the first time using an in-situ image-based boroscopic technology.
• RAME-β cyclodextrins increased the aLL by 84 %
• Kinetic study showed that RAME-β cyclodextrins reduce the rate-limiting effect of the nonanal concentration.
• Increasing RAME-β cyclodextrins concentration decreases the dependency of the reaction rates on the conversion progress.

The role of cyclodextrins in the acceleration of the reaction rate in a biphasic hydroformylations – ScienceDirect

The role of cyclodextrins in the acceleration of the reaction rate in a biphasic hydroformylations

How does cyclodextrin-based catalysis work?

carbohydrates,

Cyclodextrin-based catalysis leverages the unique structure of cyclodextrins, which form inclusion complexes with reactants, intermediates, or catalysts.

Their cavities create sterically restricted, non-polar environments that enhance reaction efficiency and selectivity, protecting unstable intermediates from side reactions. Through covalent or noncovalent modifications, cyclodextrins are combined with metal catalysis, achieving high yields and selectivity in one-pot reactions. These catalysts are also integrated into advanced materials like metal-organic frameworks, supporting unique applications.

As a result, cyclodextrin-based catalysis aligns well with green chemistry principles and offers significant contributions to sustainable chemical processes.

photo credit: 10.1139/v06-039

Mirror-image cyclodextrins

Today's cyclodextrin, ,

today’s cyclodextrin:
Do you often take a good look in the mirror?

Nobel laureate Sir Fraser Stoddard, Daniel W. Armstrong, and their team report the syntheses of three mirror-image CDs—namely, α-, β- and γ-L-CDs, which are composed of six, seven and eight α-1,4-linked L-glucopyranosyl residues, respectively.

The availability of L-CDs has enabled the elucidation of an unprecedented chiral self-sorting of a racemic modification of β-CDs in the solid state and an investigation of the chiral recognition of enantiomeric fenchone by α-L-CD. This research identifies a missing piece of the cyclodextrin jigsaw and sets the stage for scientists to explore the mirror-image world of naturally occurring CDs.

Mirror-image cyclodextrins | Nature Synthesis

Preparation of 6-Monohalo-β-cyclodextrin Derivatives with Selectively Methylated Rims via Diazonium Salts

carbohydrates,

Great cyclodextrin chemistry by Konstantin Lebedinskii and Jindřich Jindřich preparing a series of 6-monohalo (Cl, Br, and I) β-cyclodextrin derivatives with various types of methylations. This new method opens the way for preparing poorly investigated monofunctionalized selectively methylated cyclodextrins.

Preparation of 6-Monohalo-β-cyclodextrin Derivatives with Selectively Methylated Rims via Diazonium Salts | ACS Omega

Reversible Light-Induced Dimerization of Secondary Face Azobenzene-Functionalized β-Cyclodextrin Derivatives

drug delivery,

Fantastic cyclodextrin chemistry by Carmen Ortiz Mellet, Jose Manuel Garcia Fernandez, and Francisco Mendicuti et al.
β-cyclodextrin (βCyD) derivatives equipped with aromatic appendages at the secondary face exhibit tailorable self-assembling capabilities. Supramolecular species can thus form that, at their turn, can engage in further co-assembling with third components in a highly regulated manner; the design of nonviral gene delivery systems is an illustrative example.

See the full article here!

Functional group polarity-modulated formation of liquid crystals of amphiphilic cyclodextrins

Today's cyclodextrin, ,

Today’s cyclodextrin:
At CarboHyde, we also deal with amphiphilic CDs; this application from this Canadian collaboration caught my attention.
Pseudo-face-to-face symmetry in the native CDs represents a distinctive advantage to designing amphiphilic materials capable of self-assembly into liquid crystals. In this work, a new family of amphiphilic β-CD derivatives possessing 14 stearoyl chains (non-polar) and 7 functionalized tetraethylene glycols were synthesized using an improved design and more efficient chemistry, and the synthetic targets showed excellent ability to form stable hexagonal columnar mesophases. Studies of a lithium composite revealed fast local Li-ion exchange processes with very low activation energies, suggesting the benefit of using these materials as potential electrolytes for high ionic conductions. The results from this work can guide the design of future generations of CD-based LC materials for ion conduction.

University of Calgary – Austin Che, Simon Trudel-Lachance, Jayar Espejo, Chang-Chun Ling
University of Alberta – Diganta Sarkar, Vladimir Michaelis
Simon Fraser University – Carson Zellman, Vance Williams

See the full article here: Functional group polarity-modulated formation of liquid crystals of amphiphilic cyclodextrins

Well-Defined Heparin Mimetics Can Inhibit Binding of the Trimeric Spike of SARS-CoV-2 in a Length-Dependent Manner

carbohydrates, ,

Well-defined heparin mimetics that could inhibit the binding of the SARS-CoV-2 spike or RBD to immobilized heparin or to Vero E6 cells. The inhibitory potency increased with increasing chain length, and a compound composed of four sulfated hexasaccharides linked by triazoles had a similar potency as unfractionated heparin. The heparin mimetics exhibit no or reduced binding to antithrombin-III and platelet factor 4, respectively, which are associated with side effects.

Utrecht University – Roosmarijn van der Woude, Robert de Vries et al
The University of Georgia – Lin Liu et al

See the full article here

Cyclodextrin polymers functionalized with histidine and carcinine as chelating therapeutics for copper dyshomeostasis

carbohydrates,

Fascinating breaking application of cyclodextrin polymer proposed by Noemi Bognanni, Francesco Bellia and Graziella Vecchio from Università di Catania. Based on the features of cyclodextrins, they derivatized cross-linked cyclodextrin polymers with histidine or carcinine moieties and found that amylase enzymes do not hydrolyze cyclodextrin polymers. The new polymers can form copper(II) complexes and may act as nanochelators to counteract copper(II) dyshomeostasis-related diseases. Furthermore, the copper(II) complexes show superoxide dismutase activity, similar to free carcinine and histidine complexes. The antioxidant biological activity of the copper(II) complex formed in situ may protect cells from oxidative damage related to #copper dyshomeostasis.

See the full article here