Degradation of the second-generation grubbs metathesis catalyst with primary alcohols and oxygen - Isomerization and hydrogenation activities of monocarbonyl complexes

Reaction of the second-generation Grubbs metathesis catalyst [RuCl2(=CHPh)(H(2)IMes)(PCy3)] (2) (H(2)IMes = 1,3-dimethyl-4,5-di-hydroimidazol-2-ylidene) with primary alcohols in the presence of a base produced the complexes [RuClH(CO)(PCy3)(2)](3) and [RuClH(CO)(H(2)IMes)(PCy3)](5). When benzyl alcohol was used, the ruthenium phenyl complexes [RuClPh(CO)(PCy3)(2)] (4) and [RuClPh(CO)(H2I-Mes)(PCy3)] (7) were formed in addition to 3 and 5. Complex 7, characterised by an X-ray structure analysis, was also formed on exposure of 2 to oxygen. The isomerization and hydrogenation activity of 7 was determined and compared with that of 3 and 4. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.