Borohydride/ethanol reduction of RuCl 3(PMe 2Ph) 3

Abstract

Reaction of mer-RuCl 3(PMe 2Ph) 3 with NaBH 4 in ethanol at 25 °C gives mer-RuH(η 2-BH 4)(PMe 2Ph) 3. In the presence of chloride ion, this reacts with NaBH 4/ethanol at reflux to give a 1:1 mixture of cis,mer-RuH 2CO(PMe 2Ph) 3, 1a, and mer-RuHClCO(PMe 2Ph) 3, 1b, identified by decoupling in the 1H and 31P NMR, IR, and, for 1a, X-ray crystallography. In the absence of chloride ion, pure RuH(BH 4)(PMe 2Ph) 3 in refluxing ethanol still converts to RuH 2CO(PMe 2Ph) 3, 1a, which represents unusually mild conditions for decarbonylation of ethanol. Crystallographic data for RuH 2CO(PMe 2Ph) 3: triclinic, P 1 with (−160 °C): a = 12.752(4) Å, b = 11.759(4), c = 9.487(3), α = 75.96(2)°, β = 107.13(2), γ = 102.25(2) and Z = 2.