Methylated cycloamyloses (cyclodextrins) and their inclusion properties

Casu, Benito; Reggiani, M.; Sanderson, G. R.

doi:10.1016/0008-6215(79)80006-3

Cited by 100 publications

(39 citation statements)

References 17 publications

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“…However, permethylated a-and f+-cyclodextrins, when used above their melting point or as solutions in polysiloxane (DC-710) in packed columns, gave retention times that were greater for iso-alkanes than for n-alkanes, and this was attributed to the formation of inclusion complexes. [71] In gas-solid chromatography (GSC) a-and P-cyclodextrin polyurethane resins,[721 a-, p-, and y-cycl~dextrins,[~~* 741 hexakis(2,6-di-0-methyl)-a-cyclodextrin, and heptakis(2,6-di-O-methyl)-f+-cyclodextrin[751 were applied for the selective separation of positionally isomeric arenes (e.g., xylene and lutidine isomers); P-cyclodextrin polymers were found to be unsuitable for this purpose. [761 The packed columns used have low efficiencies, and consequently it was not possible to observe separation of enantiomer~.…”

Section: Gas Chromatographic Separation Of Achiral Compoundsmentioning

confidence: 97%

Gas Chromatographic Separation of Enantiomers on Cyclodextrin Derivatives

Schurig

Nowotny

1990

Angew. Chem. Int. Ed. Engl.

406

152

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In investigations concerned with the phenomenon of molecular chirality, the use of gas chromatography for the enantiomeric analysis of stable, volatile compounds is a technique of steadily growing importance. ['] In the last three years an important breakthrough in gas-chromatographic separation of enantiomers has been achieved by using alkylated cyclodextrins (a, p, and y) as chiral stationary phases in high-resolution capillary columns. In academic and commercial practice two different and complementary strategies have been adopted up to now. In the first, alkylated cyclodextrins are diluted with polysiloxanes and coated on glass or fused silica capillary columns. In the second, lipophilic per-n-pentylcyclodextrins and hydrophilic di-n-pentyl-and hydroxyalkylpermethylcyclodextrins are coated directly in the form of liquid phases onto suitably pretreated glass or fused silica surfaces. These techniques permit enantiomer separations not only for polar diols and alcohols, derivatized hydroxycarboxylic acids, amino acids, sugars, and alkyl halides, but also for nonpolar alkenes, cyclic saturated hydrocarbons, and metal 7~ complexes. An important aspect for practical applications is that in many cases the enantiomers can be separated without previous derivatization. Whereas the resolution of racemates of unfunctionalized hydrocarbons is attributed to an enantioselective hostguest inclusion complex, some observations indicate that for polar guest molecules additional enantioselective interactions are also involved. The new chiral stationary phases can be used over a wide range of temperatures (25 to 250 "C). The technique described is likely to become widely adopted as a simple, accurate and highly sensitive method for the enantiomeric analysis of chirdl compounds that can be vaporized without decomposition. It will also stimulate future research aimed at finding universal cyclodextrin phases and elucidating the mechanisms of enantioselectivity.

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Section: Gas Chromatographic Separation Of Achiral Compoundsmentioning

confidence: 97%

Gas Chromatographic Separation of Enantiomers on Cyclodextrin Derivatives

Schurig

Nowotny

1990

Angew. Chem. Int. Ed. Engl.

406

152

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“…The C6-OH groups are the more reactive, and the C3-OH the less reactive in given experimental conditions [41,42,46]. This allows the preparation of several groups of CD derivatives: methylated [45,69,70] (di-, tri-, and random derivatives), hydroxyalkylated [46,71,72] (hydroxyethyl and hydroxypropyl groups), acetylated [73,74], carboxyalkylated [45,46] (carboxymethyl group), aminoalkylated [45,46,58] (diethylaminoethyl group), ether derivatives or branched CDs [45,46,58,68]. Mono-, bi-and poly-functionalized CDs were synthesized [58,68].…”

Section: Cyclodextrinsmentioning

confidence: 99%

Synthesis and applications of adsorbents containing cyclodextrins

Crini¹,

2002

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Synthesis and applications of adsorbents containing cyclodextrinsCyclodextrins (CDs), which possess a hydrophobic cavity, have a remarkable capacity to form inclusion complexes with various molecules through host-guest interactions. It is well known that the usefulness of CDs is due to the combination of the inclusion properties and structural features of these molecules. CDs are used extensively in separation science because CD-complexation phenomena offer a procedure of choice for separation of compounds and extraction processes, and provide a useful and versatile tool for protecting the environment. The present review shows the advantages accruing from the use of adsorbents containing cyclodextrins, in particular in chromatographic separations and in waste water treatment. The main goal of this review is to provide a summary of the information concerning the synthesis of materials containing CDs and to give a general overview of the different possible applications of CDs as sorbents in the field of separation techniques. Recent and continuing interest in these adsorbents is evident from the number of papers that appear each year in the literature.

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“…Per-O-methylated CDs have attracted considerable attention due to their solubility both in water [3] and in organic solvents [4]. On the other hand, inclusion complexes of methylated CDs are usually more stable than the corresponding complexes of unmodified CDs [3]. For these reasons, the controlled chemical synthesis of modified methylated CDs having a few specifically located hydroxyl groups available for the preparation of more elaborate molecular systems represents a true challenge for synthetic chemists [5].…”

mentioning

confidence: 99%

“…They function as host molecules, forming inclusion complexes with a wide variety of hydrophobic guest compounds in aqueous solution [2]. Per-O-methylated CDs have attracted considerable attention due to their solubility both in water [3] and in organic solvents [4]. On the other hand, inclusion complexes of methylated CDs are usually more stable than the corresponding complexes of unmodified CDs [3].…”

mentioning

confidence: 99%