C-N coupling products derived from proline (26), phenylalanine (28), valine (29) or pipecolic acid (30, 32) were successfully obtained in good to excellent yields. In order to compete favorably with TCPhth, synthetically relevant N-heterocycles bearing free N-H bonds were evaluated. Using proline-derived RAE 22, the corresponding C-N coupling products with a variety of benzimidazoles (26, 40), imidazoles (33, 39, 41), and pyrazoles (31, 32, 35-38) were obtained. Non-symmetrical heterocycles such as benzotriazole (34) could also be accommodated, providing the product in a 5:1 N1/N2 ratio of regioisomers. A range of functional groups with different electronic properties were also tolerated (38, 41, 45). Since the radical process is orthogonal to classical transition metal-catalyzed cross-coupling reactions, different heteroaryl halides (35-37) and heteroaryl boronic esters (31, 32) could be well tolerated. The strategy was successfully applied in the modification of bioactive molecules, such as theophylline (42, 57%, single regioisomer). The successful coupling using thiabendazole (43, 61%) provides another illustrative example of the orthogonal reactivity to transition metals, as the Lewis-basic sites on both starting material and product could inhibit catalysis by binding to a metal center. In the absence of external nucleophiles, the product of decarboxylative amination via formal CO2 extrusion was obtained. For this process, both α-amino RAEs and α-oxo RAEs reacted, giving hemiaminal-type structures such as 44 and 45 in good yields. Overall, this strategy is complementary to the photochemical protocol reported by Fu and co-workers, allowing the use of α-heteroatom RAEs, instead of unbiased alkyl substrates. To shed light into the mechanism, we monitored the catalytic reaction of α-amino RAE 22 by NMR with 10 mol% of bismuthinidene 1 at -40 °C using DMF-d7 as solvent. In this scenario, the pair of rotamers of α-amino alkyl-bismuth(III) intermediate 23 accumulated upon consumption of the RAE, coexisting with bismuthinidene 1. It is important to mention that complex 23 was characterized by reaction of 1 with 22 in a separate stoichiometric experiment (see Supplementary Information for details). The accumulated 23 decays into 1 after 1 h at -20 °C (Fig. , slow Bi(I/II/III) pathway). However, we observed that the consumption of RAE 22 to give decarboxylative-amination product 24 occurs at a faster rate than the former process (for details on kinetic analysis, see Supplementary Information). Thus, an alternative pathway should be considered in which in-cage radical pair 23' reacts through SET, leading to iminium cation 46 upon regeneration of Bi(I) (Fig. , fast Bi(I/II) pathway). Competing radical recombination of 23' leads to some accumulation of 23, which eventually collapses into the reaction product (24) and 1. Overall, the radical oxidative addition appears to be the rate-limiting step of the dominant pathway, as suggested by the continuous presence of 1 throughout the entire course of the reaction.