Dearomatization of Indoles via a Phenol-Directed Vanadium- Catalyzed Asymmetric Epoxidation and Ring-Opening Cascade

Abstract

An enantioselective dearomatization of indole derivatives was realized by the complexes derived from the vanadium complex VO(acac)2 and C2-symmetric bis-hydroxamic acid (BHA) ligands. The reaction proceeded via asymmetric epoxidation and ring-opening by the linked phenol cascade, affording 5a,6,10b,11-tetrahydrochromeno[2,3-b]indol-10b-ol derivatives in up to 83% yield and 98% ee under mild reaction conditions.