Design and synthesis of binaphthol-derived chiral ketone catalysts for dioxirane-mediated asymmetric epoxidation of olefins

Binaphthol-derived chiral ketones 1a-c were synthesized and were shown to serve as active catalysts for asymmetric epoxidation of olefins using Oxone®, although their enantioselectivities were not high. However, very interestingly, the stereochemical outcome of the resulting epoxides implicates that in the epoxidation using 1a-c, the planar transition state may be more favorable than the spiro transition state.