With a streamlined set of conditions in hand for the radical quaternization of olefins and carboxylates, the scope was examined as illustrated in Table . In general, these highly chemoselective conditions tolerate a range of functional groups including carbamates amides, alkyl halides, epoxides, aryl halides, esters, alcohols, nitriles, tertiary amines, ketones, ureas, and electron-rich/deficient heterocycles. It is particularly noteworthy that alkyl bromides, terminal alkynes as well as an alkyl boronate, remain intact during this quartenization despite their notorious reactivity in both transition-metal catalyzed couplings and radical chemistry. Similarly, aryl iodides and electron-deficient aryl chlorides are left untouched despite their common use in radical cross couplings. In the case of olefins, preferential reactivity can be achieved during the RAE-RAE coupling whereas less reactive olefins are spared when employing the RAE-olefin coupling. Stabilized radicals can also be coupled (α-heteroatom, benzylic) derived from a-heteroatom containing acids. In the case of RAE-RAE couplings of such substrates, FeOEP led to a dramatically increased yield. Complex pharmaceutically relevant structures can be coupled efficiently resulting in quaternary center containing analogs 36-40. The direct installation of allcarbon quaternary centers within saturated heterocycles is a particularly challenging motif to construct by conventional polar bond analysis; this quaternization allows an intuitive coupling from readily accessible heterocyclic fragments (10, 11, 12, 15, 16). The reactions described above are extremely simple and practical to perform using inexpensive reagents, a rapid setup time, and are amenable to gram-scale preparation (see 41 and 34). The absence of oxygen in conditions A/B (Schlenk or glovebox conditions are not required, just a simple Ar balloon) allowed facile scaling to gram quantities with no change in yield, and pointed to internal oxidative turnover, i.e. an overall redox neutral process (see Table ). These features bode well for adoption in a parallel/combinatorial synthesis campaign wherein ubiquitous, bench-stable precursors can combine delivering long sought-after complex libraries rich in sp 3 content including quaternary carbons.