Synthesis pathways to Mn(V) compounds have traditionally relied on solid-state reactions at temperatures about 1000 °C, but for the last decade, syntheses down to 250 °C have been made possible by using aqueous precipitation in highly alkaline solutions, and by developing hydroflux approaches. In its common occurrence, a hydroflux is a mixture of alkali hydroxide with small amounts of water that enables a dramatic decrease of the melting point compared to the pure hydroxide melt. The hygroscopic salt retains water even at elevated temperatures, so that the water vapor pressure is also well below that achieved in hydrothermal conditions. Therefore, a hydroflux retains some of the properties of the parent molten hydroxide, like its high basicity and ability to dissolve a wide range of oxides, but the use of controlled amounts of water provides additional versatility, especially the possibility to tune the acid-base properties of the medium, hence possibly the concentration of reactive species, their speciation and product selection.