Homogeneous catalysis in water: a remarkable salt effect in the hydrogenation of propionaldehyde with RuCl2(tppts)3 and related complexes [tppts =(m-NaSO3C6H4)3P]

Abstract

New water soluble Ru^II complexes, e.g. RuHl(tppts)₃[tppts =(m-NaSO₃C₆H₄)₃P], exhibit in the presence of various salts an extremely high catalytic activity in the hydrogenation of aldehydes, mechanistic studies indicating clearly that the salt effect occurs both via the cation and the anion in the catalytic cycle; the electrophilic cation favours an unusual type of aldehyde coordination and reaction mechanism as the anion modifies the coordination sphere around the ruthenium atom.