On this basis, the use of gaseous alkanes as C1-C4 radical donors represents a straightforward and efficient strategy to bypass the need for traditional alkylating agents, which often have low sustainability and generate significant chemical waste in their preparation and subsequent use. This approach could provide a modular platform for the late-stage alkylation of medicinally relevant heteroarenes using readily available, low-cost and atom-efficient feedstocks. However, the high bond dissociation energy (BDE), the limited solubility in common organic solvents, and the gaseous nature of these alkanes still pose challenges to their routine use as chemical reagents. To address these obstacles, our group has recently demonstrated that hydrogen atom transfer (HAT) photocatalysis under continuous-flow conditions offers an effective strategy to generate carbon-centered radicals from abundant and inert volatile alkanes. The use of continuousflow reactors has notably advanced the chemistry of gaseous reagents, improved gas-liquid mass transfer and enhancing the practicality of handling such reagents. Despite these advancements, only a limited number of reaction manifolds currently utilize gaseous hydrocarbons as alkylating agents. While there are some examples in the literature, no general or practical protocol has been established for the direct introduction of C1-C4 alkyl fragments via Minisci-type reactions using light alkanes. With this in mind, we propose that photoinduced iron-catalyzed ligand-to-metal charge transfer (LMCT) could be employed to cleave the strong C(sp 3 -H) bonds of C1-C4 alkanes under mild conditions, enabling efficient and late-stage photocatalytic alkylation of heteroarenes (Figure ). Building on this concept, in this study, we present a modular and robust platform for the introduction of short alkyl fragments into a variety of pharmaceutically relevant heteroarenes using inexpensive carbon-based gaseous feedstocks. Our method was successfully applied to the late-stage modification of marketed drugs, and we demonstrated its scalability using a commercially available continuous-flow photoreactor.