Styrenes are widely utilized synthetic precursors for a range of polymerization and hydro-/dual-functionalization reactions. Chemists commonly probe the mechanism of these reactions by selectively incorporating deuterium onto the vinyl positions of the styrene derivative. There have been several catalytic methods reported to either completely label the vinyl group or selectively label the β-position with deuterium. An α-selective variant, however, has yet to be developed. This seminar will present a new Brønsted base-catalyzed approach to label the α-position with 100% α:β selectively. Improving access to these useful isotopomers will have significant applications for their use in mechanistic studies and as precursors to medicinally-relevant chiral deuterated benzylic stereocenters, positions frequently prone to in vivo metabolic oxidation.