We demonstrated the light-induced synthesis of the hindered and polyfluorinated dialkyl ethers using congested tertiary alcohols and polyfluorinated alcohols. A wide range of tertiary alcohols bearing active groups or bulky structures were successfully accommodated in this system. Moreover, other nucleophilic coupling partners, including water, benzoic acids, thiols, silanols, and tributyltin hydride, were compatible, highlighting the broad tolerance of this strategy. The gram-scale synthesis and effective incorporation of challenging ether motifs into drug analogues underscored the practical utility of this approach. Moreover, the rapid and modular derivatization of a marketed drug exhibited its potential in expanding the chemical diversity to aid drug discovery efforts. Finally, the mechanistic investigations and DFT studies revealed that the major process involved the photoinduced formation of singlet carbenes followed by metal-free O-H insertion.