Iron^III‐catalyzed Chemoselective Cycloaromatization Reactions for the synthesis of 5‐Brominated Benzo[<i>b</i>]fluorenones

Abstract

Abstract A Fe III ‐catalyzed cycloaromatization reaction of acyclic diaryldiyn‐3‐ones has been established. The reaction proceeds under gentle catalytic conditions with good functional group tolerance, to offer a straightforward and chemoselective avenue to 5‐brominated benzo[ b ]fluorenones. An allenoate‐type nine‐membered organoferric cyclic species and an alternative concerted mechanism were proposed in this reaction. magnified image