2024/02/28 by Jesse B. Kidd, Tahoe A. Fiala, Wesley B. Swords +6 · 1 voice
Chemistry · Energy · #Radical Photochemical Reactions #Catalytic C–H Functionalization Methods #CO2 Reduction Techniques and Catalysts
paper · pdf · doi:10.26434/chemrxiv-2024-b5llr
openalex publication_date 2024/02/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/15
The Paternò–Büchi reaction is the [2+2] photocycloaddition of a carbonyl with an alkene to afford oxetane products. Enantioselective catalysis of this classical photoreaction, however, has proven to be a long-standing challenge. Many of the best-developed strategies for asymmetric photochemistry are not suitable to address this problem because the interaction of carbonyls with Brønsted or Lewis acidic catalysts can alter the electronic structure of their excited state and divert their reactivity towards alternate photoproducts. We show herein that an alternative triplet rebound strategy enables the stereocontrolled reaction of an excited-state carbonyl compound in its native, unbound state. These studies have resulted in the development of the first highly enantioselective catalytic Paternò–Büchi reaction, catalyzed by a novel hydrogen-bonding chiral Ir photocatalyst.