Synthesis of monosubstituted derivatives of cyclodextrins

Katedra organické chemieDepartment of Organic ChemistryPřírodovědecká fakultaFaculty of Scienc

Synthesis and properties of monosubstituted derivatives of cyclodextrins

This Ph.D. thesis deals with synthesis of monosubstituted cyclodextrin derivatives and investigating their properties. Alkylation of -cyclodextrin with allyl or cinnamyl bromide followed by peracetylation of remaining hydroxyl groups and separation of isomers resulted in the set of peracetylated 2I - O-, 3I -O- and 6I -O-alkylated cyclodextrins in up to 27% yields. Oxidative cleaveage of peracetylated allyl or cinnamyl derivatives resulted in a complete set of peracetylated 2I -O-, 3I -O- and 6I -O- formylmethyl or carboxymethyl derivatives which are useful precursors for preparation of regioselectively monosubstituted derivatives of -cyclodextrin. Moreover, a quick method to recognize single 2I -O-, 3I -O- and 6I -O- monosubstituted peracetylated cyclodextrins from each other using only 1 H NMR spectrum has been proposed. Ru-carbene complex catalyzed cross-metathesis of monoallyl -, -, and -cyclodextrins with perfluoroalkylpropenes resulted in the formation of the corresponding perfluoroalkylated cyclodextrins. The reactions proceeded under standard reaction conditions and the desired compounds were obtained in reasonable yields. Dynamic light scattering measurements proved the ability of the prepared compounds to aggregate in water solution forming nanoparticles in the range of tens and..

Synthesis of monosubstituted derivatives of cyclodextrins

1 Synthesis of monosubstituted derivatives of cyclodextrins Abstract This thesis is focused on a preparation of a set of exactly defined monosubstituted derivatives of -CD for subsequent utilization in organic synthesis. Cinnamyl or allyl group is very suitable for the preparation of monosubstituted derivatives of CD, because these groups contain nonaromatic double bond, which can be widely modified. Peracetylated 2I -O-, 3I -O-, and 6I -O-allyl and 2I -O- and 3I -O-cinnamyl derivatives of -CD mentioned in this thesis were prepared in yields 3.7 - 13 %. Position of allyl and cinnamyl group was determined by 2D NMR techniques. Possibility of derivatization of allyl and cinnamyl derivatives was exemplified by transformation of peracetylated 2I -O-, and 6I -O-allyl and 3I -O-cinanmyl derivatives to peracetylated 2I -O-, 3I -O-, and 6I -O-formylmethyl derivatives via reductive ozonolysis. These aldehydes were oxidized by Jones reagent to 2I -O-, 3I -O-, and 6I -O-carboxymethyl derivatives. Keywords: cyclodextrins, monosubstitution, allyl, cinnamyl, formylmethyl, carboxymethy

Synthesis of substituted cyclodextrins

Cyclodextrins are naturally occurring, non-toxic and biodegradable cyclic oligosaccharides. The main feature of cyclodextrins is the ability to encapsulate lipophilic compounds, which has led to many applications. Although many cyclodextrin derivatives have become available on the market, their price is in the range of fine chemicals, and thus, they are still often synthesised in laboratories. The actual number of cyclodextrin derivatives exceeds 11,000, but new cyclodextrin derivatives are still needed for more advanced applications. Therefore, many beginners in cyclodextrin chemistry struggle with a reliable choice of a synthetic route. This review focuses on cyclodextrin derivatives that can be subsequently modified. Indeed, the modification of an already substituted cyclodextrin with a suitable functional group is much easier than the optimisation of the substitution for every new cyclodextrin derivative desired. This review describes the synthesis of different types of cyclodextrin derivatives: persubstituted, randomly substituted, persubstituted at selected positions, selectively substituted and monosubstituted cyclodextrins

Synthesis of monosubstituted derivatives of cyclodextrins

Katedra organické chemieDepartment of Organic ChemistryPřírodovědecká fakultaFaculty of Scienc

Cyclodextrin-Functionalised Nanomaterials for Enantiomeric Recognition

Cyclodextrins, which are glucose-based cyclic oligosaccharides, are materials that can act inherently as chiral selectors, with many reports of the application of cyclodextrins in enantioseparation. However, many studies have encountered the problem of insufficient enantioselective performance of the chiral selector. One of the main reasons is due to low surface concertation's, whereby interaction between the chiral selector and analyte usually occurs at a surface. Thus, scientists have been trying for the last two decades to overcome this problem, with the incorporation of nanomaterials being promising as they possess a large surface area which allows for the accommodation of a higher concentration of the chiral selectors. Herein, we outline nanomaterial-cyclodextrin conjugates that work in tandem to achieve or enhance enantioselectivity through various methods such as chromatography, adsorption, and removal using magnetic nanoparticles, or enantiorecognition using electrochemical techniques