Facile access to fused 2D/3D rings via intermolecular cascade dearomative [2 + 2] cycloaddition/rearrangement reactions of quinolines with alkenes

Abstract Hybrid fused two-dimensional/three-dimensional (2D/3D) rings are important pharmacophores in drugs owing to their unique structural and physicochemical properties. Preparation of these strained ring systems often requires elaborate synthetic effort exhibits low efficiency, thus representing a limiting factor drug discovery. Here, we report two types energy-transfer-mediated cascade dearomative [2 + 2] cycloaddition/rearrangement reactions quinoline derivatives with alkenes, which provide straightforward avenue 2D/3D pyridine-fused 6−5−4−3- 6−4−6-membered systems. Notably, this strategy features excellent diastereoselectivity that bypasses the general reactivity selectivity issues photochemical cycloaddition various other aromatics. Tuning aza-arene substitutions enabled selective diversion iridium photocatalysed energy transfer manifold towards either cyclopropanation or cyclobutane-rearrangement products. Density functional theory calculations revealed scenario be operative.