This compound, with CAS number 220114-01-2, is a chiral ruthenium(II) complex. Its structure features a ruthenium(II) center coordinated to a chiral diphosphine ligand, specifically a derivative of (S)-(-)-2,2'-bis(di(3,5-xylyl)phosphino)-1,1'-binaphthyl (often referred to as a Xyl-SDP derivative), and a chiral diamine ligand, (2S)-(+)-1,1-bis(4-methoxyphenyl)-3-methyl-1,2-butanediamine. The presence of two chloride ligands completes the octahedral coordination sphere. This complex is a highly efficient and enantioselective catalyst primarily used in asymmetric hydrogenation reactions. The combination of the chiral, electron-rich Xyl-SDP phosphine ligand and the chiral diamine ligand creates a well-defined chiral environment around the ruthenium center, enabling the highly selective reduction of specific prochiral substrates, such as ketones and functionalized olefins, to produce chiral alcohols and other valuable intermediates with high enantiomeric excess (ee). Its design is a classic example of Noyori-type catalysts. Due to its specialized and sophisticated structure, it is not a general-purpose reagent but a pre-formed, high-performance catalyst for advanced synthetic chemistry, particularly in the pharmaceutical and fine chemical industries for the production of enantiomerically pure compounds. It is typically handled under inert atmosphere due to air and moisture sensitivity.