The synthesis of the novel ionic Ru–alkylidenes [Ru[(4-CO2)(1-CH3)Py+)]2(IMesH2)(CH-2-(2-PrO)-C6H4)][OTf−]2 (1, IMesH2=1,3-dimesitylimidazolin-2-ylidene, Py=pyridine, OTf−=triflate) and [RuCl[(4-CO2)(1-CH3)Py+)](IMesH2)(CH-2-(2-PrO)-C6H4)][OTf−] (2) is reported. Catalysts 1 and 2 were successfully used in various metathesis reactions under biphasic liquid–liquid conditions using 1-butyl-2,3-dimethylimidazolium tetrafluoroborate and heptane as liquid phases. Ruthenium leaching into the heptane phase was very low (<0.4 %), translating into Ru contamination of the products between 0.3 and 2.5 ppm. Both 1 and 2 exhibited comparable reactivity in organic solvents and under biphasic conditions. Catalyst 1 and 2 were also successfully used in the continuous metathesis of methyl oleate and 1,7-octadiene under supported liquid–liquid conditions. Finally, the disproportionation of the monocarboxylato monochloro substituted Ru–alkylidene 2 was traced by 1H NMR analysis at 40 °C, thereby demonstrating the formation of complex 1 and the neutral complex [RuCl2(IMesH2)(CH-2-(2-PrO)-C6H4)].