Ru-MCM-41 catalysts for diastereoselective hydrogenation

RuMCM-41 catalysts were prepared by deposition of several complexes from th eir solvents: of Ru acetylacetonate from its ether solution, of cis-dichlor obis(2,2 ' -bipyridine) Ru in chloroform, of di-mu chlorobis((p-cymene)chlo ro Ru(II)) in chloroform and of dichloro(l,5-cyclooctadiene) Ru(II) dissolv ed in pyridine. The catalysts were characterized as prepared and after seve ral reactions cycles by: adsorption-desorption isotherms of N-2 at 77 K, XR D, FTIR, and XPS. The above catalysts were used in the liquid phase hydroge nation of a F prostaglandin intermediate. A strong leaching of Ru was obser ved, but after four cycles the catalysts remained unchanged in activity and diastereoselectivity. The stereoselectivity was found to be influenced by the nature of the precursor complex. In the presence of the catalyst prepar ed from di-mu chlorobis((p-cymene)chloro Ru(II)) the natural-like product w as obtained. (C) 2001 Elsevier Science B.V. All rights reserved.