Enantioselective Bromination of Silyl Enol Ethers with Chiral Pentacarboxycyclopentadienyl Bromide

Abstract Chiral pentacarboxycyclopentadienyl bromide reagents were synthesized to accomplish enantioselective bromination of silyl enol ethers to give corresponding α-bromoketone products in good yields and up to 77% ee. A catalytic version of this reaction was also demonstrated through the combination of Lewis acid activators and diethyl 2,2-dibromomalonate as stoichiometric achiral bromine source.