Supported organometallic complexes - Part XXXV. Synthesis, characterization, and catalytic application of a new family of diamine(diphosphine)ruthenium(II) complexes

The novel diamine(dppp)ruthenium(II) complexes 3L(1)-3L(12) have been obtained by reaction of equimolar amounts of Cl2Ru(dppp)(2) (2) with the diamines L-1-L-12 in excellent yields. Within a few minutes one of the diphosphine ligands was quantitatively exchanged by the corresponding diamine. X-ray structural investigations of 3L(1), 3L(2), and 3L(8) show triclinic unit cells with the space groups P (1) over bar (3L(1), 3L(2)) and P 1 (3L(8)). Whereas in solution all these complexes prefer a trans-RuCl2 configuration, in the solid state cis-(3L(1), 3L(2)) and trans-isomers (3L(8)) were observed. With the exception of 3L(5), 3L(6), and 3L(12) all mentioned ruthenium complexes are highly catalytically active in the hydrogenation of the alpha,beta-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 > 99% with high turnover frequencies (TOFs) under mild conditions. (C) 2002 Elsevier Science B.V. All rights reserved.