We posited that a complexation-assisted deprotonation strategy for the catalytic generation of a allenylmetal reagent from an alkyne (Scheme 1D, top left) could enable the desired enantioselective propargylic C-H silylation reaction. Liming Zhang and coworkers previously demonstrated the utility of this approach using bifunctional Au/Brønsted base catalyst for intramolecular coupling of alkyne and aldehydes, 16a while, more recently, our group reported an intermolecular propargylic allylation in the presence of an Ir catalyst (Scheme 1D, bottom left). 16b Given these results, the substantial precedent for Ir-catalyzed silylation chemistry, and the high affinity of Ir toward Si, we hypothesized that an Ir/chiral phosphoramidite system would allow for the stereocontrolled installation of silyl groups at the propargylic position through the interception of an allenyliridium intermediate with a silicon-centered electrophile. In this Communication, we disclose the successful implementation of this strategy using silyl trifluoromethanesulfonate (triflate) reagents as electrophiles, leading to the development of a highly enantioselective and regioselective protocol for the Ir-catalyzed propargylic α-C-H silylation of alkyl aryl, alkyl alkenyl, and dialkyl acetylenes (Scheme 1D, right). In our initial studies, 1-phenyl-1-butyne (1a) was selected as the model alkyne substrate for propargylic silylation. Based on the hypothesis that a cationic Ir species is the active catalyst, 16b a cationic precursor, [Ir(cod)2] + BF4 -(cod = 1,5-cyclooctadiene) was first evaluated. Together with triethylsilyl triflate (TESOTf, 2a) as the silylation reagent, the desired product was obtained with excellent enantioselectivity though in modest yield (Table , entry 1). However, contrary to initial expectations, [Ir(cod)Cl]2 exhibited superior reactivity among commercially available Ir(I) sources (entries 1 to 3). Subsequent experiments demonstrated that, under reaction conditions, the silyl triflate reagent rapidly abstracts Cl -from the phosphoramidite-ligated Ir center to generate the active cationic catalyst (vide infra). A 2:1 ratio of chiral ligand to metal was found to give considerably better catalytic activity compared to a 1:1 ratio (entry 4 vs. entries 3 and 5). In contrast to previously reported Ir-catalyzed C(sp 3 )-H silylation reactions, the hydrosilane Et3SiH was found to be ineffective (entry 6). 17g-i The use of triethylsilyl chloride as the reagent likewise did not afford the product (entry 7). However, when a prestirred mixture of Et3SiH and TfOH was used as the reagent, the silylation product was formed in high yield and excellent enantioselectivity (entry 8), indicating that silyl triflate formed in situ was an effective reagent. Among a range of organic and inorganic bases examined, 2,2,6,6-tetramethylpiperidine (TMPH) was found to be uniquely effective (entry 9 and Supporting Information). Finally, control experiments omitting iridium source, ligand, and base one at a time demonstrated the necessity of each of these components in this transformation (entry 10).