A new protocol for in situ dioxirane reactions: stoichiometric in oxone and catalytic in fluorinated acetophenones.

[reaction: see text] Dioxiranes made in situ from the commercially available tetrafluoroacetophenones (7, 8) and pentafluoroacetophenone (9) are reported for highly efficient epoxidation of olefins for the first time. Studies showed that ketone 7, 8, or 9 can be used in catalytic amount (0.2 equiv) with only 0.6 equiv of Oxone (equal to 1.2 equiv of peroxymonosulfate) to selectively oxidize diene 1 to epoxide 2. The epoxidation reactions of dioxiranes of fluoroacetophenones are compared with the recently described complementary aliphatic acyclic fluorinated ketones.