Acceleration of a dipolar cycloaddition by a simple bisamide receptor

A bisamide receptor has been synthesized which is capable of binding and, hence, polarizing maleimide. The hydrogen bonds formed between the receptor and maleimide alter its inherent reactivity. Full kinetic investigations, performed using 1H NMR spectroscopy and computer-based simulation, reveal that the formation of the 1:1 complex increases the rate of the cycloaddition between maleimide and diphenylnitrone fivefold.