K. Barry Sharpless

2001 — for work on chirally catalyzed oxidation reactions. Sharpless developed the asymmetric epoxidation of allylic alcohols (Ti/tartrate, "Sharpless epoxidation") and the asymmetric dihydroxylation of alkenes with $\ce{OsO4}$ anchored to cinchona ligands, giving chemists general tools for building stereocentres. 2022 — for the development of click chemistry and its use in bioorthogonal chemistry. Sharpless defined click reactions as modular, high-yield couplings such as the Cu-catalyzed azide–alkyne cycloaddition (CuAAC), which click molecular units together even inside living cells.