2026-04-13T05:46:38Zhttps://recercat.cat/oai/request
oai:recercat.cat:2072/3763132024-12-20T22:08:24Zcom_2072_300912com_2072_4427col_2072_301309
RECERCAT author de Pedro Beato, Eduardo author Mazzarella, Daniele author Balletti, Matteo author Melchiorre, Paolo 2020-07-03T15:19:07Z2024-04-23T10:36:44Z 2020-07-03T15:19:07Z2024-04-23T10:36:44Z 2020-06-04 http://hdl.handle.net/2072/376313 https://doi.org/10.1039/d0sc02313b We detail a strategy that uses a commercially available nucleophilic organic catalyst to generate acyl and carbamoyl radicals upon activation of the corresponding chlorides and anhydrides via a nucleophilic acyl substitution path. The resulting nucleophilic radicals are then intercepted by a variety of electron-poor olefins in a Giese-type addition process. The chemistry requires low-energy photons (blue LEDs) to activate acyl and carbamoyl radical precursors, which, due to their high reduction potential, are not readily prone to redox-based activation mechanisms. To elucidate the key mechanistic aspects of this catalytic photochemical radical generation strategy, we used a combination of transient absorption spectroscopy investigations, electrochemical studies, quantum yield measurements, and the characterization of key intermediates. We identified a variety of off-the-cycle intermediates that engage in a light-regulated equilibrium with reactive radicals. These regulated equilibriums cooperate to control the overall concentrations of the radicals, contributing to the efficiency of the overall catalytic process and facilitating the turnover of the catalyst. eng L'accés als continguts d'aquest document queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons:http://creativecommons.org/licenses/by-nc-nd/4.0/ Photochemical generation of acyl and carbamoyl radicals using a nucleophilic organic catalyst: applications and mechanism thereof info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion URL https://recercat.cat/bitstream/2072/376313/5/20_Photochemical%20generation%20of%20acyl%20and%20carbamoyl%20radicals%20using%20a%20nucleophilic%20organic%20catalyst%20applications%20and%20mechanism%20thereof.pdf File MD5 5923be8169d943b83c72a13cc129fd26 2664006 application/pdf 20_Photochemical generation of acyl and carbamoyl radicals using a nucleophilic organic catalyst applications and mechanism thereof.pdf URL https://recercat.cat/bitstream/2072/376313/1/20_Photochemical%20generation%20of%20acyl%20and%20carbamoyl%20radicals%20using%20a%20nucleophilic%20organic%20catalyst%20applications%20and%20mechanism%20thereof.pdf.txt File MD5 4f5ccbcd5c61376ad9be6c0b2904b9ad 63198 text/plain 20_Photochemical generation of acyl and carbamoyl radicals using a nucleophilic organic catalyst applications and mechanism thereof.pdf.txt