Synthesis of Aminodiborane through the Reaction of Ammonia Borane with Acids

A facile method for the synthesis of aminodiborane (NH2B2H5, ADB) has been developed through the reaction of ammonia borane (NH3BH3, AB) with an ether solution of hydrogen chloride (HCl·Et2O) at room temperature. In addition, N-alkyl substituted ADB derivatives were synthesized by reacting N-alkyl substituted AB with HCl·Et2O at 50 °C. The mechanistic studies indicated that the nucleophilic substitution reaction of the B–H bonding pair electrons and the dihydrogen bonding interaction play an important role. This work paves an alternative way to prepare amine borane compounds.