Phosphine‐catalyzed (3+2) Annulation of Isoindigos with Allenes: Highly Enantioselective Creation of Two Vicinal Quaternary Stereogenic Centers

Construction of contiguous all‐carbon quaternary stereogenic centers is a long‐standing daunting challenge in synthetic organic chemistry. In this report, we introduce a phosphine‐catalyzed enantioselective (3+2) annulation reaction between allenes and isoindigos containing two identical/different oxindole moieties as a powerful strategy for the construction of spirocyclic bisindoline alkaloid core structures. The reported reactions are featured with high chemical yields, excellent enantioselectivities, and very good regioselectivities, and are highly useful for creating structurally challenging natural products.

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