A highly efficient manganese-catalysed hydroperoxidation of carbon–carbon double bonds of enynes as well as styrene derivatives using N-hydroxyphthalimide, N-hydroxybenzotriazole or N-hydroxysuccinimide was developed. This reaction proceeded at room temperature through the direct incorporation of molecular oxygen present in air. The required catalytic loading of manganese(III) acetylacetonate is extremely low (generally 0.02–0.5 mol%, and a minimum of 0.001 mol%).