Stereochemistry Controls Dihydrogen Bonding Strengths in Chiral Amine Boranes Adducts

The growing interest in exploiting novel concepts of non‐covalent interactions in catalysts and supramolecular chemistry made us revisit a special kind of hydrogen bonding: the dihydrogen bond (DHB), formed between a classical hydrogen bond donor and a hydridic hydrogen as acceptor. Herein, we investigate how the strength of the N−H(δ+)⋅⋅⋅(δ−)H−B interaction and hence the DHB‐driven self‐aggregation of amine‐borane adducts is governed by steric effects by comparing the structures and binding enthalpies of various chiral derivatives. For a diastereomeric pair of amine‐boranes prepared from a chiral secondary amine, we show that the stereochemistry at the nitrogen has significant influence on the interaction enthalpy. Based on this finding, N‐chiral amine boranes can be envisioned to become interesting building blocks in supramolecular chemistry to fine‐tune the formation dynamics of assemblies.