Scheme 2 Scope of 1,1-disubstituted alkenes. Reaction conditions: 1 (0.50 mmol, 1.0 eq.), 2 (0.75 mmol, 1.5 eq.), [Ir(COD)Cl]2 (0.01 mmol, 2 mol %) in 1,4-dioxane (2.0 mL, 0.25 M) at room temperature for 4 h under N2. Isolated yields. With the establishment of the simple and mild condition, we next sought to investigate its generality towards diverse sulfurinvolving 1,1-disubstituted alkenes (Scheme 2). The reactions of (hetero)aryl allyl sulfides bearing different functional groups were first carried out to probe the efficiency of this catalytic system, all of which went smoothly to afford corresponding hydrosilylated products in good to excellent yields (3a to 3f). Alkyl allyl sulfides could likewise participate in this process, providing the desired products 3j-3k with high efficiency. This Please do not adjust margins Please do not adjust margins protocol is applicable to homoallylic sulfides as well, with the observation of slightly decreased yields (3l to 3n). Besides the methyl group at the  position of alkenes, ethyl and phenyl groups are likewise well tolerated, which allows for the various side-chain decorations in potential polymerization applications (3o to 3r). To reveal the importance of sulfur unit in facilitating this hydrosilylation process, several 1,1-disubstituted alkenes bearing no thioether group were tested under this condition. GC/MS and 1 H NMR analysis (Supplementary Figures ) gave no evidence for the formation of hydrosilylation adducts (3s to 3u). Intriguingly, the mixture of 1u with Et3SiH was also stable in the presence of [Ir(COD)Cl]2 (Supplementary Figure ), which might be due to that the prior coordination of 1u with iridium catalyst prevents its interaction with Et3SiH. To probe the potential application of this protocol in polymer science, we then tested its usability in dihydrosilylation reactions (Scheme 3). In the presence of PhMe2SiH, the dialkenyl-substituted sulfide 1v was converted into dihydrosilylated product 3v in 79% isolated yield. Furthermore, dihydro-substituted silane 2b proved to be effective in modifying and connecting sulfur-containing olefin units (3ab, 3cb and 3ib). These positive results prompted us to investigate the efficiency of this method in hydrosilylation polymerizations (Scheme 4a). 1 H NMR result evidenced the quantitative conversion of monomers (Scheme 4b). GPC analysis illustrated the successful formation of polymer P1 (Mn = 3063 Da, Mw = 5951 Da, PDI = 1.94, Scheme 4c).