Dihydrogen Phosphate Anion-Templated Synthesis of Urethane-Based Macrocycle Containing Perfluoroalkyl Chain

The efficient synthesis of macrocycles has been a challenging subject in supramolecular chemistry. This study shows that H2PO4- acts as a template in the synthesis of novel macrocycles containing a long perfluoroalkyl chain in their backbone. Density functional theory (DFT) calculations indicate that H2PO4- preorganizes the reaction intermediate in the transition state through multiple hydrogen-bonding interactions, promoting the cyclization reaction and increasing the yield of the macrocycle. The introduction of the fluoroalkyl chain increases the acidity of the neighboring CH2 group, thereby enhancing the hydrogen-bonding interactions in the intermediate complex.