MPVO Reactions Catalyzed by Mesoporous Materials

Mesoporous materials of the MCM-41 type have also been used in MPVO reactions. Creyghton et al. reported the use of both H- and Na-exchanged activated MCM-41 (Si/Al = 15) in the reduction of 4-te/t-butylcyclohexanone in i-PrOH under reflux [23,24]. After 6 h, conversion to the alcohols was only 10 % the thermodynamically favored trans compound was obtained with 90% selectivity. It was proposed that the activity resides in co-ordinatively unsaturated Al atoms which can react with the alcohol to form an activated alkoxide species. 

Increased activity was found by Anwander et al. who grafted aluminum alkoxide moieties on siliceous mesoporous MCM-41 [25]. These materials were first prepared by a one-step solution impregnation by treating Al(Oi-Pr)3 with partially dehydroxylated MCM-41 in hexane. In a second approach, MCM-41 was reacted 

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