The epoxidation of 2-styrylchromones 2a-h using Jacobsen's Mn(III)[salen] complex 1 as catalyst is reported for the first time. Several studies were performed using both hydrogen peroxide and iodosyl-benzene as oxidants, in order to obtain the α,□-epoxy-2-styrylchromones 3a-h regioselectively. Due to the low reactivity of the substrates and the highly unstable character of the formed epoxides, reactions should be interrupted at lower conversions to obtain acceptable yields, especially when hydrogen peroxide is used.
ASJC Scopus subject areas
- Organic Chemistry