Cyclopentadienyl and pentamethylcyclopentadienyl ruthenium complexes as catalysts for the total deoxygenation of 1,2-hexanediol and glycerol?

Green Chemistry Pub Date: 2010-12-24 DOI: 10.1039/C0GC00255K

Abstract

The ruthenium aqua complexes [cp*Ru(OH2)(N–N)](OTf) (cp* = η5-pentamethylcyclopentadienyl, N–N = 2,2′-bipyridine, phen = 1,10-phenanthroline, OTf? = trifluoromethanesulfonate) and the acetonitrile complex [cpRu(CH3CN)(bipy)](OTf) (cp = η5-cyclopentadienyl) are water-, acid-, and thermally stable (>200 °C) catalysts for the hydrogenation of aldehydes and ketones in sulfolane solution. In the presence of HOTf as a co-catalyst, they effect the deoxygenation of 1,2-hexanediol to 1-hexanol and hexane. Glycerol is deoxygenated to 1-propanol in up to 18% yield and under more forcing conditions completely deoxygenated to propene. The structure of the acetonitrile pro-catalyst [cpRu(CH3CN)(bipy)](OTf) has been determined by X-ray crystallography (space groupP[1 with combining macron] (a = 9.3778(10) ?; b = 10.7852(10) ?; c = 11.1818(13) ?; α = 101.718(5)°; β = 114.717(4)°; γ = 102.712(5)°; R = 3.95%).

Graphical abstract: Cyclopentadienyl and pentamethylcyclopentadienyl ruthenium complexes as catalysts for the total deoxygenation of 1,2-hexanediol and glycerol
Recommended Literature