Photo‐Induced Catalytic Dearomative Coupling of <i>N</i> ‐Heteroarenes

Naturally occurring dimeric products have attracted considerable attention from both chemists and pharmacologists. The construction of pseudo-dimers often requires elaborate synthetic effort with low efficiency. Dearomatization reactions represent an ideal method to transform planar aromatics into 3D skeletons, which has attracted increasing interest in medicinal chemistry and total synthesis. Herein, we present a dearomative dimerization of N-heteroarenes under mild photochemical conditions. Through additive regulation, the catalytic dearomative cross-coupling of two distinct quinolines could also be achieved. With aromatic compounds as coupling partners, this strategy provides a straightforward avenue to pseudo-dimers of N-heteroarenes. Combined experimental and computational mechanistic studies reveal the intertwined EnT/SET nature and offered guidelines for synthesizing novel bridged polycycles. In addition, this strategy provides an effective approach for constructing functional polymers with high atom economy and environmental benefits via metal-free, one-pot polymerization. Furthermore, the synthetic transformations offer a complementary route to access formal crossed products that were previously inaccessible.