Computed ammonia affinity for evaluating Lewis acidity of organoboronates and organoboronamides

Abstract

Lewis acidity of organoboronates [B(pin), B(neop), B(cat), B(eg), B(nad)] and organoboronamides [B(dan), B(aam), B(mdan)] has been found to be unifiedly evaluated by computed ammonia affinity (AA), while other methods [LUMO energies, global electrophilicity index (GEI), fluoride ion affinity (FIA)] were only partially applicable. The relationships between the AA values and such structural characters including the B–X bond lengths, the X–B–X angles, and the changes in the B–X bond lengths in the formation of the ammonia adducts were also described.