During the past twenty years, cyclodextrins (CDs) have proven to be very effective in aqueous biphasic catalysis. They could act as molecular receptors for numerous organic substrates and favour their conversion at the aqueous/organic interface. Recently, new applications have been found for CDs in aqueous catalysis. CDs can now be defined as polyfunctional entities between the substrate-containing phase and the catalyst-containing phase. In this paper, we highlight the latest breakthroughs in the use of CDs in catalysis through several examples from the literature.
During these last years, cyclodextrins have greatly contributed to the development of catalytic processes in water. These cyclic oligosaccharides composed of 6(α), 7(β) or 8(γ) glucopyranose units improve the mass transfer in aqueous-organic two-phase systems and are useful compounds to design new catalysts. Thus, chemically modified cyclodextrins can be used to: (1) significantly increase the rate and selectivity of reactions catalyzed by water-soluble organometallic complexes; (2) design new water-soluble ligands for aqueous organometallic catalysis; (3) stabilize catalytically active noble metal nanoparticles in water; (4) facilitate reactions catalyzed by supported metals or metallic powder in water.