Theoretical calculation-based ammonia affinity: A unified method for evaluating Lewis acidity of organoboronic acid derivatives

Theoretical calculation-based ammonia affinity (AA) has been found to unifiedly evaluate Lewis acidity of organoboronic acid derivatives [boronates: B(pin), B(neop), B(cat), B(eg), B(nad); boronamides: B(dan), B(aam), B(mdan)], while other methods [LUMO energies, global electrophilicity index (GEI), fluoride ion affinity (FIA)] were only partially applicable. The AA analysis estimated that the Lewis acidity of the B(mdan) moiety was sufficiently diminished but stronger than the B(dan) moiety; this was experimentally demonstrated by excellent stability toward hydrolysis and direct cross-coupling with a weak base.