2026-04-17T05:34:13Zhttps://recercat.cat/oai/request

oai:recercat.cat:2072/5328002024-12-20T22:54:00Zcom_2072_300912com_2072_4427col_2072_301309

Insights into the Role of Graphitic Carbon Nitride as a Photobase in Proton-Coupled Electron Transfer in (sp3 )C‒H Oxygenation of Oxazolidinones Galushchinskiy, Alexey Zou, Yajun Odutola, Jokotadeola Nikačević, Pavle Shi, Jian-Wen Tkachenko, Nikolai López, Núria Farràs, Pau Savateev, Oleksandr Graphitic carbon nitride (g-CN) is a transition metal free semiconductor that mediates a variety of photocatalytic reactions. Although photoinduced electron transfer is often postulated in the mechanism, proton-coupled electron transfer (PCET) is a more favorable pathway for substrates possessing X−H bonds. Upon excitation of an (sp2)N-rich structure of g-CN with visible light, it behaves as a photobase—it undergoes reductive quenching accompanied by abstraction of a proton from a substrate. The results of modeling allowed us to identify active sites for PCET—the ‘triangular pockets’ on the edge facets of g-CN. We employ excited state PCET from the substrate to g-CN to selectively cleavethe endo-(sp3)C−H bond in oxazolidine-2-ones followed by trapping the radical with O2. This reaction affords 1,3-oxazolidine-2,4-diones. Measurement of the apparent pKa value and modeling suggest that g-CN excited state can cleave X−H bonds that are characterized by bond dissociation free energy (BDFE) ≈100 kcal mol−1. 2023-04-14T08:57:01Z 2024-04-23T11:11:56Z 2023-04-14T08:57:01Z 2024-04-23T11:11:56Z 2023-04-14T08:57:01Z 2024-04-23T11:11:56Z 2023-02-28 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/2072/532800 https://doi.org/10.1002/anie.202301815 eng info:eu-repo/semantics/openAccess This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. RECERCAT (Dipòsit de la Recerca de Catalunya)