Efficient Entry to the Pyrroloquinoline Core of Martinella Alkaloids via Novel Base-catalyzed Mukaiyama-Mannich Reaction

An efficient enantiocontrolled entry to Martinella alkaloids was achieved based on the unexpected discovery that a catalytic amount of KH/dicyclohexyl-18-crown-6 induced an intramolecular Mukaiyama-Mannich reaction of imine 3, leading to a cascade sequence involving, a novel silyl group migration to furnish the pyrroloquinoline core 6.