Hydrogenation of PhCH2CHO catalyzed by ruthenium complex containing "polymer-attached" ligand prepared by living ring-opening metathesis polymerization

Various pyridine ligands attached to the polymer chain end could be prepared by the living ring-opening metathesis polymerization (ROMP) using well-defined the Schrock-type molybdenum-alkylidene initiator of Mo(CHCMe2Ph)(N-2,6-(Pr2C6H3)-Pr-i) (OtBu)(2), and the possibility for use of this ligand in catalysis has been examined for hydrogenation of PhCH2CHO in the presence of Ru(acetylacetonato)(3) (Ru(acac)(3)) (in xylene, at H-2 10 atm). Significant increase in the activity was observed if the above polymer was employed as the ligand, although the activity decreased upon the addition of pyridine or 4-methylpyridine instead. The prepared catalyst could be recovered by pouring the reaction mixture into methanol, and could be reused without decrease in the activity. (C) 2002 Elsevier Science B.V. All rights reserved.