Methods for direct allylic C-H functionalizations are among the most attractive transformations to streamline organic synthesis as it maximizes the step-and atomeconomy to generate stereodefined allylic species amenable to further chemical transformations, thus minimizing the cost and waste. Traditional allylic C-H functionalization reactions generally require the catalysis of transition-metals such as Pd, Cu, and Ir, in which involve the formation of an allyl-metal complex via C-H activation followed by being attacked by an intra-or intermolecular nucleometallation (Fig. ). Recently, the radical cleavage of an allylic C-H bond via hydrogen atom transfer is also developed to generate carbon-centered radical intermediates, which could be involved in following radical processes or transtion-metal catalysis. These two strategies proved to be powerful for organic synthesis and extensively investigated. The stereochemistry outcomes heavily rely on the property of transitionmetals and anchoring ligands and are mostly dominated by thermodynamic control, leading to the formation of C-H functionalizaiton products with more stable Eselectivity. On the contrast, the realization of Z-selective allylic C-H functionalizations is more challenging and remains elusive. On the other hands, organothiathrenium salts could be easily prepared from arenes and alkenes by thianthrenation using stoichiometric thianthrene S-oxide or phenoxathiine 10-oxide as the mediators, which could serve as the precousors for both cross-coupling reactions and radical precesses. This two-step strategy arises potential chemical space for manipulating C-H bond of arenes and alkenes. Recently, Ritter group reported seminal work on selective C-H functionalizations of arenes via thianthrenation, providing access to diverse chemical bonds from aryl C-H bonds (Fig. ). Wang group developed the Pd-catalyzed site-selective C-H borylation and arylation of arenes by employing the same strategy (Fig. ). Recently, Shi group developed the utilization of alkyl thianthrenium salts for C-B and C-C bond formation. Wickens group reported the electrochemical synthesis of 1,2-disubstituted thianthrenium salts from alkenes and thianthrene, which were used as the key intermediates to produce aziridines by C-N formation. In 2020, Ritter group developed elegant examples of C-H functionalizations of alkenes via the isolated vinyl thianthrenium salts, giving alkylation, alkynylation, arylation, halogenation, and trifluorosulfinylation of alkenes (Fig. ). Despite the promising progress, all the above-mentioned C-H functioanlization reactions are restricted to ipso-functionalizations of arenes or alkenes via thianthrenation by replacing the C-S bond in the thiathrenium salts. Yet, no example of C-H functionalization at the allylic position of alkenes was reported. Herein, we reported the metal-free selective allylic C-H functionalizations of alkenes via thianthrenation (Fig. ). The mild conditions allow for the allylic C-H nitrogenation, oxygenation, and carbonation of alkenes at room temperature by the formation of C-O, C-C, and C-N bonds, affording diverse esterifications, thioesterifications, etherifications, aminations, arylation of allylic C-H bonds. Notably, the metal-free C-H functionalizations deliver allylic esters, ethers, amines, ammonium salts, and amides with preferred Z-selectivity.