In summary, we have developed a radical oxidative addition of redox-active carbon electrophiles to lowvalent bismuth, based on the SET from a well-defined Bi(I) complex to alkyl RAEs and KS. This process led to a family of alkyl-bismuth(III) complexes, which were found to be in equilibrium with the corresponding in-cage radical pair formed by bismuth(II) and a free alkyl radical. Unbiased alkylbismuth(III) complexes are stable and can be characterized both in solution and in solid state. On the other hand, α-amino alkyl-bismuth(III) intermediates collapse back to bismuth(I) upon releasing iminium cations, which can be trapped by external N-nucleophiles. This led to the development of a bismuth-catalyzed C-N cross-coupling reaction, using complex N-heterocyclic compounds. This new type of radical catalysis is promoted by bismuth in an autonomous manner, through a radical Bi(I/II) or Bi(I/II/III) redox cycle, without the need of a photoredox system, a chemical oxidant, an external base, or an electrochemical set-up. Overall, these findings open up a field of radical couplings by a main-group element and pave the way for the rational design of synthetically relevant transformations based on Bi radical catalysis.