The present disclosure relates to a method for effecting catalytic selective oxidation in liquid phase comprising a perfluorinated solvent and an olefinic compound with molecular oxygen to produce an epoxide. The method may provide enhanced selectivity to the epoxide of greater than 60%. The olefinic compound may be ethylene, propylene, butenes, 1-octene, butadiene, allyl chloride, allyl alcohol, styrene, and the like. The perfluorinated solvent may be perfluoro methyldecalin, perfluorodecalin, perfluoroperhydrophenanthrene, perfluoro (butyltetrahydrofuran), isomers thereof, or a combination thereof. In some embodiments, the method includes catalytically epoxidizing, in a liquid phase comprising a perfluorinated solvent, propylene with molecular oxygen to produce propylene oxide. A system for carrying out the method is also provided, the system comprising a source of a perfluorinated solvent, and a liquid phase reactor fluidly connected with the source, and configured for effecting catalytic selective oxidation, in a liquid phase comprising the perfluorinated solvent, of an olefinic compound with molecular oxygen to produce an epoxide.