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Boronic acids are a class of intensively explored compounds, which according to their specific properties have been intensively explored in last decades. Among them phenylboronic acids and their derivatives are most frequently examined as receptors for diverse carbohydrates. In turn, there is a large gap in basic research concerning complexation of catecholamines by these compounds. Therefore, we decided to undertake studies on interaction of chosen catecholamines, namely: noradrenaline (norephinephrine), dopamine, L-DOPA, DOPA-P (phosphonic analog of L-DOPA) and catechol, with simple phenyl boronic acid PBA by means of potentiometry and NMR spectroscopy. For comparison, the binding properties of recently synthesized phenylboronic receptor 1 bearing aminophosphonate function in meta-position were investigated and showed promising ability to bind catecholamines. The protonation and stability constants of PBA and receptor 1 complexes were examined by potentiometry. The obtained results demonstrated that PBA binds the catecholamines with the following affinity order: noradrenaline ⩾ dopamine ≈ L-DOPA > catechol > DOPA-P, while its modified analog 1 reveals slightly different preferences: dopamine > noradrenaline > catechol > L-DOPA > DOPA-P.

Two groups of new boronic acids containing aminophosphonate functions were synthesized and characterized by NMR spectroscopy and ESI-MS. Both groups of compounds were obtained by simple reactions of prepared in situ tris(trimethylsilyl) phosphite with a corresponding imine. The synthesized compounds may serve as a potential new class of building blocks, BNCT agents and supramolecular host molecules.

In order to combine the properties of aza-macrocycles and aminophosphonates, a new tetraaminophosponic macrocyclic molecule has been synthesized. This potential receptor for organic molecules as well as for metal cations was obtained by condensation, hydrophosphonylation, and deprotection. The second synthetic step was performed using di(trimethylsilyl) phosphite, which enabled us to obtain the final product in high yield. NMR studies strongly suggested that the α-aminophosphonate macrocycle was reached as a symmetric meso-derivative.