Asymmetric Oxidative Rearrangement of Tetrahydro-β-Carbolines Catalyzed by Anionic Stereogenic-at-Cobalt(III) Complexes

Abstract

An asymmetric oxidative rearrangement of tetrahydro-β-carbolines catalyzed by anionic stereogenic-at-cobalt(III) complexes has been developed, providing a distinct cobalt-based catalytic mode for the synthesis of chiral spirooxindoles. A range of products were obtained in good yields with good to high enantioselectivities (25 examples, up to 94.5:5.5 er). The method shows notable compatibility with excess achiral Brønsted acid, and its utility was demonstrated by gram-scale synthesis, conversion to (–)-Coerulescine, and mechanistic studies.