Owing to the wide range of oxidation states in which first-row metals can exist, their reactivity towards radical intermediates allows them to forge bonds from easy-to-access radical precursors. For the sake of illustration, consider a general C(sp 2 )-C(sp ) linkage. Following conventional retrosynthetic analysis along the lines of polar bond disconnections would lead to powerful cross-coupling tactics such as Suzuki, Kumada-Corriu, Negishi, and Stille most often mediated by a palladium catalyst (Figure ). In such cases, the nucleophilic component is either introduced as a C(sp 2 ) anion equivalent (organomagnesium, organozinc, organoboron, etc.) which can impact chemoselectivity and functional group compatibility. Alternatively, a C(sp ) electrophile in the presence of an exogenous can be used in a cross-electrophile coupling. In contrast, following a radical disconnection leads the practitioner to building blocks such as carboxylic acids and alkyl esters pioneered by Baran and MacMillan as well as alkyl halides popularized by Weix, Gong, and Molander. While the emergence of radical-based cross couplings has expanded the range of chemical space accessible in the synthesis of fine chemicals, there yet lie limitations. Whether following a polar or radical disconnection, the use of thermally driven crosscouplings relies on the energy needed for the reaction being a core component of the starting materials. However, the high reactivity of starting materials can be detrimental to the overall functional group compatibility of the process and strongly influence synthetic design necessitating unattractive protecting group strategies. A similar limitation can be found in widely employed C-heteroatom cross-coupling reactions (Figure ). Ullman, Buchwald-Hartwig, and Chan-Evans-Lam remain powerful synthetic tools, yet the harsh conditions needed for challenging elementary steps compromise overall functional group compatibility in the pursuit of densely functionalized architectures. The merger of transition metal catalysis with photochemical and electrochemical modulation has become a popular strategy to overcome such limitations (Figure ). By either oxidizing or reducing a metal catalyst, a photo-or electrocatalyst can coax reactivity towards otherwise reluctant functionality with tight control of chemoselectivity. In addition, the redox perturbation of a metal catalyst's oxidation state can permit entry to elusive catalytic cycles and lower the energy barriers to challenging elementary steps. Combining the reactivity properties of redox control with broad access to radical intermediates has expanded the toolkit of the modern chemist to access valuable chemical space from simple, safe, and often readily available starting materials. Specifically, photochemistry and electrochemistry both have had profound impacts on C(sp 2 )-C(sp 3 ), C(sp 3 )-C(sp 3 ), and C-Heteroatom cross-coupling. In addition to these tactics, the use of metallic reductants such as Zn and Mn to drive reductive crosscoupling has emerged as an alternative answer to such challenges. While such reactions have similar mechanistic features and practical advantages, they are outside the scope of our labs' work and will not be discussed.