Water-Solubilization of Acyclic Cucurbiturils for Arenes and Aromatic Aldehydes and the Promotion for the Generation of Two Hydrazine-Based Macrocycles

Abstract

The promotion of two sulfate or carboxylate-bearing acyclic cucurbiturils for the water-solubility of arenes and aromatic aldehydes is described. 1 H NMR experiments reveals that sulfate-bearing acyclic cucurbituril (acCB-1) signficantly improves the water-solubility of a number of arenes and aldehydes. For 4,4'-dimethylbiphenyl and biphenyl-4,4'dicarbaldehyde, the solubility can be improved to 8.9 and 11.2 mmol/L, respectively. 19 F NMR experiments demonstrate that carboxylate-bearing acyclic cucurbituril can increase the water-solubilities of pentafluorotoluene and hexafluorobenzene to 5.6 and 3.0 mmol/L, respectively. It is also found that the water-solubilization of acCB-1 for aromatic aldehydes can promote their reaction with acylhydrazines to form hydrozone derivatives. By making use of this promotion, two hydrazone-based macrocycles can be formed from the coupling reactions of two aromatic dialdehdes and one diacylhydrazine in water.