Continuous flow oxidation of alkynes with KMnO4 for the synthesis of 1,2-diketone derivatives

In this study, we report an advanced chemical transformation of both terminal and internal alkynes to 1,2-diketones and keto-carboxylic acids, using KMnO4 as oxidizing reagent and utilizing the efficiency of flow chemistry technology over traditional batch methods. Our continuous flow system, incorporating a sonication bath, prevents MnO2 slurry formation in the reaction coil, avoiding obstruction of the reactor. Noteworthy, the integration of in-line liquid-liquid separation, streamlining seamless work-up for consistently high-purity products (yields: 80-99%). This novel synergy of flow chemistry and liquid-liquid separation not only enhances transformation efficiency but also provides valuable insights for future synthetic methodologies.