A Class of C2 and Pseudo C2 Symmetric Ketone Catalysts for Asymmetric Epoxidation. Conformational Effect on Catalysis
摘要:
A class of C-2 and pseudo C-2 symmetric ketones with one fused ring at each side of the carbonyl group have been prepared from quinic acid and found to be effective catalysts for the asymmetric epoxidation of a variety of olefins. Electron deficient olefins such as enones can be efficiently epoxidized. Encouragingly good enantioselectivity is also obtained for the epoxidation of styrenes. The studies show that the ketone conformation plays an important role in the reactivity and selectivity of the catalyst.