Tetrakis(dimethylsulfoxide)dichlororuthenium(II) is a versatile ruthenium(II) complex used as a catalyst in homogeneous catalysis. It is particularly known for facilitating the selective oxidation of primary alcohols to aldehydes and secondary alcohols to ketones under mild conditions, often with co-oxidants like tert-butyl hydroperoxide (TBHP). The complex also enables transfer hydrogenation reactions for reducing carbonyl compounds. Its high solubility in polar solvents, stability, and ease of ligand exchange make it an excellent precursor for synthesizing other ruthenium catalysts employed in C-H activation, cross-coupling, and olefin metathesis processes. This compound is valuable in the synthesis of pharmaceuticals, fine chemicals, and complex organic molecules.