In modern synthetic chemistry, arylation reactions serve as indispensable tools for assembling building blocks relevant to medicinal and crop science applications. Consequently, transition metal-catalyzed cross-coupling has emerged as the gold standard for assembling such units, often achieved through the combination of prefunctionalized starting materials, including aryl or alkyl halides and organometallic reagents. While these prefunctionalized fragments offer high chemofidelity, they also come with drawbacks such as low atom economy, high toxicity, and often moisture and air instability. In the industrial preparation of these building blocks, main routes involve the halogenation of either the corresponding olefin with hydrohalic acids or the conversion of the corresponding alcohol (Scheme 1B). To illustrate, considering the introduction of an ethyl unit via conventional cross-coupling, the apparent C2 synthon is bromoethane or species derived from it (e.g., organoboron, organozinc reagents). Intriguingly, bromoethane derives from the hydrobromination of ethylene, which in turn originates from the energy-intensive steam cracking of naturally occurring ethane (Scheme 1C). Consequently, these drawbacks have spurred growing interest within the scientific community in implementing new strategies capable of utilizing more sustainable and abundant alkylating agents, ideally directly from these alkane feedstocks. While the direct introduction of alkyl fragments (C1-4) into aryl halides through C-H activation of light alkanes is theoretically the ideal approach, such transformation remains elusive and restricted to few examples to date, employing limited coupling partners. For instance, the first reported example by Nelson et al. exploited the generation of stabilized aryl cations from β-silylated aryl fluorides, capable of undergoing C-H insertion with methane. In a mechanistically distinct approach from the Chang group, a copper-catalyzed crossdehydrogenative coupling of propane and butane with activated perfluoroarenes led to the introduction of the desirable light alkyl units. However, as a generalization, the utilization of abundant gaseous alkanes as alkylating agents in transition metal catalysis has not seen significant methodological advancement and lags behind more conventional cross-coupling technologies that employ prefunctionalized coupling partners. Motivated by this gap in the literature, we aimed to develop a practical catalytic method to achieve the C(sp 3 )-H arylation of light hydrocarbons, thus providing a synthetic strategy for incorporating light alkyl fragments into (hetero)arenes (Scheme 1D). Specifically, we envisioned that the combination of photoinduced hydrogen atom transfer (HAT), nickel catalysis, and continuous-flow reaction conditions would facilitate the realization of such a C(sp 2 )-C(sp 3 ) cross-coupling platform. The primary advancement presented in this study encompasses the ability to circumvent the use of prefunctionalized alkyl derivatives, often synthesized from the parent alkane via energy-intensive and non-selective processes, which feature low sustainability profiles. Additionally, to address limitations associated with gas-toliquid mass transfer and the safety profile of handling gaseous reagents in conventional reactors, we propose the utilization of flow technology to ensure safe and rapid processing. Furthermore, the integration of high-intensity light sources and micro capillary reactors ensures uniform irradiation and short reaction times, making the overall protocol synthetically useful and scalable. Finally, comprehensive Density Functional Theory (DFT) calculations have been conducted, identifying the oxidative addition step as the most challenging aspect of this reaction blueprint, thereby offering valuable insights for future catalyst development.