Stereoselective Visible‐Light Catalyzed Cyclization of Bis(enones): A Viable Approach to the Synthesis of Enantiomerically Enriched Cyclopentane Rings

Photoredox catalytic cyclization of aryl enones in the presence visible light, promoted either by metals or organic dyes, represent a valuable strategy for synthesis cycloalkanes. The development stereoselective version such transformation, metal-free catalyst Eosin Y was studied, with aim to realize an efficient protocol in-flow enantiomerically enriched functionalized cyclopentane rings, taking advantage flow reactors technology. use chiral auxiliary on bisenone be cyclized offers straightforward and convenient option exert stereocontrol light-driven cyclization. By exploiting Evans’ oxazolidinones, affords, after removal auxiliary, 1,2-trans ring up 83/17 enantiomeric ratio. When reaction performed continuo, homemade coil photoreactor, high yields were observed. also successfully realized 3D-printed mesoreactor, without any change diastereoseletctivity process.