Vanadium-Catalyzed Asymmetric Epoxidation: Proline-Derived Hydroxamic Acids Revisited

Abstract

Structural features of ligands and substrates affecting enantioselectivity in vanadium(V)-catalyzed epoxidation of allylic alcohols were investigated. For the hydroxamic acid ligands derived from arylhydroxylamines, 2-aryl-substituted allylic alcohols emerged as the best substrates furnishing good level of enantio­selectivity.

Key words

asymmetric catalysis - epoxidations - homogeneous ­catalysis - ligands - vanadium

References and Notes

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9

Epoxidation of alcohol 1 carried out in H₂O (0 °C, 48 h) using ligand 6a produced epoxide 2 in 65% yield and 51% ee. For the reaction conditions, see ref. 6.