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Bambusurils are macrocyclic molecules that are known for their high binding affinity and selectivity toward anions. Here, we present the preparation of two bambusurils bearing fluorinated substituents and one carboxylic function. These monofunctionalized bambusurils were conjugated with crown ether and cholesterol units. The resulting conjugates were successfully tested in liquid–liquid extraction of inorganic salts and chloride/bicarbonate transport across lipid bilayers.

An upper-rim functionalized calix[4]arene-based thiourea installed onto the (R,R)-1,2-cyclohexanediamine scaffold was synthesized with a view to investigate its catalytic ability in enantioselective Michael additions. The reactions were found to conveniently proceed under solvent-free conditions, observing good to high enantioselectivities. From this preliminary study, the calix[4]arene unit is likely to play a role in affecting the conversion and to a lesser extent to the stereochemical outcome of the reactions through van der Waals contacts and C–H···π interactions with the substrates.

“Macrocyclization of Cycles with a Macrocycle.” The synthesis of a dinuclear zirconium complex bearing a 1,5-m-xylene-diyl-bridged calix[8]arene ligand and tert-butoxide groups, viaprotonolysis of the calix proligand with two equivalents of zirconium(iv) tert-butoxide, has been accomplished. 1H, 13C and two-dimensional NMR spectroscopy revealed for the complex a conformationally locked solution structure with C2vsymmetry, where the two zirconium atoms lie in close proximity. The elucidated structure has been validated through DFT calculations. The complex has been successfully used as a catalyst in the ring opening polymerization (ROP) of lactones such as rac-lactide (LA), -caprolactone (-CL) and β-butyrolactone (β-BL). The activities for the ROP of LA compares well with those for the so far reported most active group 4 complexes. Interestingly, the MALDI-TOF-MS investigations on the resulting polymer architecture revealed the highly selective formation of cyclic polymers (70–80 mol%). The cooperation of the intramolecular zirconium atoms has been proved comparing the polymerization results with those obtained using a mononuclear zirconium complex featuring a calix[4]arene ligand.