Jump to main content
Jump to site search

Issue 10, 2007
Previous Article Next Article

Heterogeneous vanadium catalysts for racemization and chemoenzymatic dynamic kinetic resolution of benzylic alcohols

Author affiliations

Abstract

Cheap and readily available oxovanadium compounds such as vanadyl sulfate (VOSO4) and vanadium oxide (V2O4) catalyze the racemization of benzylic alcohols in the absence of any additives (e.g., bases or hydrogen mediators) or co-catalysts. The reaction occurs at 80 °C in n-octane as the solvent and does not require anhydrous or oxygen-free conditions. Experiments clearly demonstrated that VOSO4 is a reusable and truly heterogeneous racemization catalyst. Insight into the reaction mechanism was obtained from 18O-labeling experiments, which showed that the formation of carbenium ion intermediates is a key step. The V-catalyzed racemization was combined with a lipase-catalyzed kinetic resolution to give a chemoenzymatic dynamic kinetic resolution of benzylic alcohols. The dynamic kinetic resolution (DKR) proceeds in one pot and does not need additives or specifically designed acyl donors. Under optimized conditions, the DKR process yields the corresponding esters in good chemical yield (>90%) and high optical purity (>99% ee).

Graphical abstract: Heterogeneous vanadium catalysts for racemization and chemoenzymatic dynamic kinetic resolution of benzylic alcohols

Back to tab navigation

Publication details

The article was received on 05 Jan 2007, accepted on 16 May 2007 and first published on 14 Jun 2007


Article type: Paper
DOI: 10.1039/B700187H
Citation: Green Chem., 2007,9, 1104-1108
  •   Request permissions

    Heterogeneous vanadium catalysts for racemization and chemoenzymatic dynamic kinetic resolution of benzylic alcohols

    S. Wuyts, J. Wahlen, P. A. Jacobs and D. E. De Vos, Green Chem., 2007, 9, 1104
    DOI: 10.1039/B700187H

Search articles by author

Spotlight

Advertisements