Density functional theory (DFT) was utilized to understand how bismuth(III) salts (BiX₃) achieve greatest activation of organic Lewis bases in a catalytic reaction. It is reported in the literature that the BiX₃ reactivity originates from its low lying Bi−X σ* orbital. In contrast to this belief, we will show here that for BiX₃ to effectively serve as a catalyst, a p orbital of bismuth needs to be involved in activating organic substrates.