β-Cyclodextrin as Supramolecular Catalyst in Organic Synthesis

Introduction

By the end of the 1960s, the methods for the laboratory-scale preparation of cyclodextrins, their structure, physical and chemical properties had been discovered. Literature survey reveals that cyclodextrins are very interesting, promising molecules in supramolecular chemistry as well as for their industrial importance. In recent years cyclodextrins have been used as catalysts in organic reactions. In this spotlight the use of cyclodextrin in organic reactions as a supramolecular catalyst is highlighted.

Cyclodextrins (CDs) are cyclic oligomers of d-glucose and are named α-, β- and γ-CD for hexamer, heptamer and octamer, respectively. [1] They have a toroidal cyclic structure with secondary hydroxyl glucose C-2 and C-3 on their more open face and the primary C-6 hydroxyl on the opposite secondary face. [2] Their ability to bind organic molecules in the hydrophobic central cavity has provided a basis for the construction of receptor models. [3] It is ­widely accepted that the binding forces involved in the ­inclusion-complex formation are van der Waals inter­actions, hydrophobic interactions, hydrogen bonding and electrostatic interactions between charged parts of guest molecule and CDs. [4]

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