Based on literature and the experimental results, a plausible mechanism is described in Fig. . First, intramolecular attack of sulfur on alkene moiety of vinylthianthrenium salt could deliver the dithianthrenium salt M1, which could further undergo site-selective ring-opening by intermolecular attack by a nucleophile to give an alkylthianthrenium salt intermediate M2. In the presence of a base, M2 would undergo a syn-elimination via TS1 to give the final allylic C-H functionalization product in favor of Z-selectivity. In summary, a unified transition-metal-free protocol for diverse functionalizations of allylic C-H bonds of alkenes by thianthrenation under mild conditions has been demonstrated for the first time. Notably, the reaction features Z-selectivity to afford multi-alkyl substituted allylic esters, thioesters, ethers, primary, secondary, tertiary amines, amides, and arenes in good yields without incorporation of any transitionmetals. One-pot procedure proved efficient to access direct allylic C-H functionalizations from alkenes. The reaction tolerates a wide range of O-, Nnucleophiles with excellent functional group tolerance, and could be applied to latestage functionalizations of natural products, amino acids, and drug-like molecules with excellent chemoselectity.