With optimized reaction conditions established, the scope of the transformation was investigated. Using commercially available trimethylsilyl (TMS) and triethylsilyl triflates as the silyl source, a diverse collection of aryl alkyl acetylenes were first examined (Table ). Substrates bearing electron withdrawing and donating aryl groups (1b-1f) provided the desired products (3b-3f) in moderate to good yield and excellent enantioselectivity, as did an ortho-substituted substrate (1c). In addition, substrates bearing a number of functional groups could all be successfully employed to deliver the desired products, including those with esters (3d, 3u), a tertiary amide (3m), a tertiary arylamine (3l), an imide (3n), a diaryl ketone (3t), and a sulfonamide (3i). Moreover, a variety of heterocycles were well tolerated in this transformation, including benzofurans (3g, 3h), thiophenes (3j, 3k), a pyrazole (3o), a carbazole (3p), an indole (3q), a phenothiazine (3r), and a quinoline (3s). In all cases examined, the protocol delivered propargylic silanes with excellent levels of stereocontrol (≥95% ee). Structurally distinct conjugated enynes (1v, 1w) and dialkyl acetylenes (1x, 1y) were also successful substrates, delivering products (3v, 3w, 3x and 3y) in moderate to high yield and good to excellent enantioselectivity (≥85% ee). Remarkably, unsymmetrical acetylene (1y) bearing two primary alkyl substituents (ethyl and phenethyl) still provided silylation product with synthetically useful regioselectivity (8.3:1 rr) for the less substituted position(3y). The regioselectivity of this transformation was examined further by subjecting methyl alkyl acetylenes to the standard reaction conditions. In the cases, silylation took place cleanly (>20:1 rr) at the terminal methyl position to give achiral propargylic silanes 4. Regioselectivity was unaffected by the presence of nitrogen or oxygen substituents on the alkyl chain. The incorporation of fragments based on bioactive molecules and pharmaceuticals, including nortriptyline (3za), sertraline (3zb), cholesterol (3zc), fenofibric acid (4f), probenecid (4g), and adapalene (4h), highlights the broad scope and functional group compatibility of this silylation protocol. We then briefly investigated the scope of silyl triflate reagents suitable for this transformation (Table ). In the case of reagents that were not available commercially (2aa-2af), we found that they could be conveniently generated by the protonolysis of the corresponding allyl-or arylsilanes with TfOH and used in situ without purification. In all cases examined, propargylic silylation products (5a-5f) were obtained in moderate to excellent yield and uniformly excellent enantiocontrol (≥94% ee). Notably, a chiral racemic silyl triflate could be used to give 5f with high levels of enantiocontrol at the propargylic position, though as a mixture of diastereomers at silicon.