Due to the inert pair effect of the heavy, organometallic compounds of Bi (III) show Lewis acid properties given the lower ability of the 6s electron pair to mix with molecular orbitals and form σ-bonds. The search for non-toxic equivalents of boronic acids in advancing the Suzuki-Miyaura carbon-carbon coupling reactions and expand the scope of carbon-nitrogen and carbon-oxygen coupling ones turned chemists' attention to organometallic bismuth chemistry. Two catalytic mechanisms were proposed in the C-C bond formation catalyzed by bismuth organometallic compounds. The major difference arises from the rate of the oxidative addition to Pd(0) into a C-Bi bond or C-O one, yielding cycles A and B, respectively (see image).