(p-Cymene)bis(mesitylcarboxylato)ruthenium(II)

Experimental procedure¹⁾:
A mixture of [Ru(MesCO₂)₂(p-cymene)] (15.0 mg, 0.027 mmol), K₂CO₃ (1.04 mmol, 2.0 eq.), 2 (96.2 mg, 0.52 mmol) and 3 (282 mg, 1.43 mmol) in dioxane (2 mL) is stirred under N₂ for 20 h at 100 °C. EtOAc (50 mL) and H₂O (50 mL) are added to the reaction mixture at ambient temperature. The separated aqueous phase is extracted with EtOAc (2 × 50 mL). The combined organic layers are washed with brine (50 mL), dried over Na₂SO₄ and concentrated in vacuo. The residue is purified by silica gel column chromatography (hexane:EtOAc = 9:1) to yield 4 (108 mg, 71%) as a colorless oil.