Furthermore, Katritzky salt 4 (Ep/2 = -1.2 V vs Fc 0/+ ) also underwent radical oxidative addition with 1 to give 10. As expected, non-chlorinated phthalimide ester 3 (Ep/2 = -2.0 V vs Fc 0/+ ) remained unreacted when mixed with 1. Besides benzyl groups, the same process occurs with primary (11), or secondary (13) RAEs, leading to stable alkyl-bismuth(III) complexes. Interestingly, the process is orthogonal to classical polar transition-metal oxidative additions, as it could be performed in the presence of an aryl bromide, giving 12 as the sole product in 93% yield (Fig ). This reactivity is a rare example where bismuth, besides emulating the redox behavior of first-row transition metals during oxidative addition, allows the isolation and characterization of the corresponding alkyl-metal species resulting from radical recombination. Furthermore, when 13 was analyzed by EPR spectroscopy a weak but steady signal of the carbon-centered radical could be observed (see Supplementary Materials), which points to 13 being a radical-equilibrium complex. Based on this, the reaction of bismuthinidene 1 with cyclopropylmethyl iodide was monitored by NMR at low temperature in the dark (Fig. ). Complete conversion to cyclopropylmethyl adduct 14 was observed within one hour at -20 °C. When the mixture was warmed to 50 °C, a slow but steady conversion to ring-opening compound 16 was observed (35% after 12 h). This indicates that homolysis of the Bi-C bond in 14 takes place, and the complex is in equilibrium with its corresponding in-cage radical pair (18). ); potential in V vs Fc 0/+ converted from V vs SCE (-2.13 V). c Yields and conversions determined by H NMR, unless noted otherwise. TCPhth = tetrachlorophthalimide.