Enabling technologies for cyclodextrins complexation, funtionalization and material grafting

Synthetic chemists are increasingly paying attention to combinations of enabling technologies with an eye to achieving the double goal of obtaining high efficiency and meeting the green criteria of energy savings and the absence of dangerous or harsh reagents. Microwave (MW), power ultrasound (US), hydrodynamic cavitation ball milling and hybrid flow-reactors are a valid and versatile alternative for process intensification in organic synthesis. We exploited MW and US for the synthesis of cyclodextrin (CDs) derivatives which can be applied in many different fields due to their unique features. The use of new MW reactor with high power (up to 1.5 kW) pressure resistant (up to 200 bar) equipped with separate multiple gas inlets, allowed us the use of a wider range of low-boiling reagents such as allylamine, butylamine and allylamine and butylamine. We also experimented MWs as powerful energy source to graft nanomaterials and fabrics with suitable CD derivatives. Simultaneous MW/US irradiation was used for the mono-functionalization of the 6-monoazido-b-CDs catalyzed by metallic copper. Thank to this procedure new cyanine-b-CD derivatives have been synthesized to be used like “turn on” or “turn off” fluorescent chemical sensors, in which fluorescence intensity is enhanced or decreased by complexation with guest molecules. Ball-milling technique was employed for the formation of CD inclusion complexes to improve the solubility and bioavailability of poorly water-soluble molecules of synthetic and pharmaceutical interest.