Supported organometallic complexes Part 34: synthesis and structures of an array of diamine(ether–phosphine)ruthenium(II) complexes and their application in the catalytic hydrogenation of trans-4-phenyl-3-butene-2-one

The novel diamine–bis(ether–phosphine)ruthenium(II) complexes Cl2Ru(η1-Ph2PCH2CH2OCH3)2(diamine)2(3L1–3L11) have been obtained by reaction of equimolar amounts of Cl2Ru(P∩O)2 (2) with the respective diamines L1–L11 in good yields. X-ray structural investigations of 3L2 and 3L8 show monoclinic unit cells with the space group P21/c. The octahedrally coordinated ruthenium atoms have each two trans-chlorides and cis-phosphines which is in agreement with NMR studies in solution. With the exception of 3L4 all mentioned ruthenium complexes are highly catalytically active in the hydrogenation of the α,β-unsaturated ketone trans-4-phenyl-3-butene-2-one. In most cases the conversions and selectivities toward the formation of the unsaturated alcohol trans-4-phenyl-3-butene-2-ol were 100% with high turnover frequencies under mild conditions.