Development of hydroxylated cucurbit[n]urils, their derivatives and potential applications

Cucurbit[n]urils (Q[n]s), a relatively new class of macrocyclic hosts with a rigid hydrophobic cavity and two identical carbonyl-fringed portals, have attracted much attention in supramolecular chemistry. Compared to the chemistry of cyclodextrins and calixarenes, the development of cucurbit[n]uril chemistry has been relatively slow, mainly due to the high chemical stability of Q[n]s, which makes them difficult to functionalize. The discovery of the direct oxidation method to yield perhydroxylated cucurbit[n] urils {(HO)(2n)Q[n]s} greatly promoted Q[n] chemistry, since (HO)(2n)Q[n]s can serve as a platform trigger for the synthesis of many other functionalized cucurbit[n]urils. The resulting products have attracted much attention for numerous potential applications. In this review, we summarize developments based on derivatives of cucurbit[n]urils hydroxylated at the equatorial positions, as well as the potential applications of these molecules. (C) 2017 Elsevier B.V. All rights reserved.