To address these challenges, Baran et al. developed an effective electrochemical strategy in which the carbocations derived from carboxylic acids were subsequently captured by tertiary alcohols to produce the hindered dialkyl ethers. This method had a broad substrate scope, whereas the carboxylic acid synthesis typically involved multiple steps. Alternative approaches, such as C-H functionalization for dialkyl ether synthesis, have been reported, while they show limited applicability to tertiary or polyfluorinated alcohols. Similarly, the hydroalkoxylation of alkenes using the cobalt catalysis can offer an elegant route to the hindered ethers, while it is restricted to simple tertiary alcohols. Another robust method to afford dialkyl ethers involves carbenoid O-H insertion, which requires the activation of diazo esters under transition-metal catalytic conditions to access metal carbenes. However, the hindered alcohols are often impractical for this approach. Recently, Koenigs et al. demonstrated the application of diazo compounds to form ethers with the polyfluorinated alcohols under blue light irradiation, indicating significant advancement. Concurrently, Rovis et al. reported the photocatalytic O-H insertions into the α-stabilized diazo compounds, but limited to primary alcohols. Despite their utility, diazo compounds as common carbene precursors are constrained by the structural limitations, instability, and susceptibility to competing reactions, necessitating diverse and readily available carbene precursors. N-tosylhydrazones have been recognized as significant alternatives to diazo compounds among various carbene precursors and are widely used in the organic synthesis because of their safety, availability, and structural diversity. Concurrently, the photoinduced reactions have offered attractive opportunities for activating and transforming the carbene precursors , particularly Ntosylhydrazones, which traditionally relied on the transition metal catalysis or thermal conditions. Despite this progress, the O-H insertion into N-tosylhydrazones with the hindered or polyfluorinated alcohols remains challenging. We hypothesized that the photoinduced O-H insertions into Ntosylhydrazones could provide a solution to this issue, drawing from our extensive experience in the photochemical activation and transformation of these compounds. The photoinduced activation of N-tosylhydrazones initiates with the formation of an in-situ donor/donor diazo intermediate which further undergoes the O-H insertion either directly into the diazo compounds or into the free carbene following the nitrogen release. And the subsequent proton transfer yields the final product. Building on this method, the hindered alcohols and weakly nucleophilic polyfluorinated alcohols smoothly underwent the O-H insertions to produce the previously challenging ethers under photoinduced conditions (Figure ). In addition to alcohols, various nucleophiles, including phenols, H 2 O, thiols, silanols, and tributyltin hydride, were also compatible with this strategy. Furthermore, our system successfully incorporated the ether groups into various pharmaceutical and natural product analogs. We also demonstrated the gramscale synthesis of the dopamine reuptake inhibitor vanoxerine and natural product derivatives, highlighting the potential of this system. At last, detailed experimental investigations and DFT studies illustrated the reaction mechanism, which was distinct from traditional metal-carbenoid O-H insertions.