<p>The proximity effect, frequently encountered in enzyme catalysis, entails bringing two or more molecules close together, forcing a reaction to occur. The presence of multiple binding sites at the active centre is required to facilitate the preorganization of reactants prior to reaction. We investigate this concept in a main-group compound by accessing a tricoordinate antimony dication, [Tp^Me2Sb]²⁺, where Tp^Me2 = tris(3,5-dimethylpyrazolyl)borate, that is charge balanced by two [B(C₆F₅)₄]⁻ anions. [Tp^Me2Sb]²⁺ readily reacts with anionic (X) and neutral (L) donor ligands, resulting in stable disphenoidal geometry complexes of the types [Tp^Me2SbX]⁺ and [Tp^Me2SbL]²⁺, respectively. Consequently, [Tp^Me2Sb(HNPh₂)]²⁺ was obtained upon the addition of HNPh₂ to the dication. As evidenced by density functional theory calculations, further treatment of [Tp^Me2Sb(HNPh₂)]²⁺ with styrene resulted in a weak van der Waals interaction between the arene ring and the 5<i>s</i> lone pair on the antimony centre, eventually facilitating a hydroamination reaction. Our investigations open avenues for exploring intermolecular processes promoted by low-oxidation-state heavier main-group compounds.</p><p></p>