Synthesis of Isoquinuclidines via Dearomative Diels–Alder Reaction of Cyclic Amidines with Indoles

The development and utilization of new dienes and dienophiles for the controlled synthesis of isoquinuclidines is highly appealing. Herein, we describe a novel strategy for diastereoselective synthesis of indoline-fused isoquinuclidines via copper-catalyzed dearomative Diels–Alder reaction of cyclic amidines with indoles. This protocol avoids the use of unstable DHPs and activated alkenes, offering a more efficient and selective approach to synthesize isoquinuclidines.