Prochiral selectivity and deuterium kinetic isotope effect in the oxidation of benzyl alcohol catalyzed by chloroperoxidase

Abstract

The chloroperoxidase-catalyzed oxidation of benzyl alcohol exhibits a very high prochiral selectivity, involving only the cleavage of the pro-S C–H bond.

References

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3. Actually, k^R_cat/k^S_cat is a measure of the intrinsic deuterium isotope effect only if the rate of release of the product from the enzyme–product complex is not kinetically significant. If this condition does not hold, the intrinsic deuterium isotope effect is expected to be larger than k^R_cat/k^S_cat(ref. 4).
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5. However, a concerted oxygen insertion, as suggested by the use of radical probe substrates [ref. 1(j), (k)], might also be compatible with the observed intrinsic k_H/k_D values.
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7. (±)-1-d was reacted with SO₄^–(from Ti^III/K₂S₂O₈ or γ-radiolysis/K₂S₂O₈) in H₂O at pH 6 (0.1 M phosphate buffer). From the molar ratio between PhCDO and PhCHO produced in the reaction, measured by GC-MS, a k_H/k_D value of 1.8 was calculated.
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