Quinic acid transformations by photocatalysis Miguel Bárbara 1,2 , N.R. Candeias 3 , C.A.M. Afonso 1 , A. Gualandi 2 , P.G. Cozzi 2 1 University of Lisbon, Portugal, 2 Università di Bologna, Italy, 3 University of Aveiro, Portugal Quinic acid (QA) is a widely occurring metabolite in plants and microorganisms 1 . The synthesis of Oseltamivir (Tamiflu) 2 , Bactobolin A 3 and Actinobolin 4 are probably the most distinct applications of QA in total synthesis. Exploration of stereoselective metal-free deoxygenation and the O,O-silyl group migration are recent examples of QA’s synthetic value 5,6 . Photoredox catalysis is a known sustainable alternative to the use of less environmentally friendly superstoichiometric oxidants and reductants. Ruthenium and iridium complexes, in combination with visible light, are efficient photocatalysts (PC’s) when powerful oxidants or reductants are needed, however, their toxicity and scarcity are a drawback for large scale and commodity chemicals synthesis. Easily accessible organic dyes represent a good alternative to metal-based PC’s 7 . The functionalization of QA and its derivatives via photoredox catalysis will be presented. Organic dyes under visible light irradiation can generate radical intermediates from QA under mild conditions. This radical generation unravels innovative ways for the synthetic modification of QA. Acknowledgements The authors acknowledge Fundação para a Ciência e Tecnologia (FCT) for financial support (PTDC/QUI- QOR/1131/2020, UIDB/04138/2020 and UIDP/04138/2020). The project leading to this application has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 951996. References 1. Arceo, E.; Ellman, J. A.; Bergman, R. G., A direct, biomass-based synthesis of benzoic acid: formic acid-mediated deoxygenation of the glucose-derived materials quinic acid and shikimic acid. ChemSusChem 2010, 3 (7), 811-3. 2. Abrecht, S.; Federspiel, M. C.; Estermann, H.; Fischer, R.; Karpf, M.; Mair, H.-J.; Oberhauser, T.; Rimmler, G.; Trussardi, R.; Zutter, U. J. C. I. J. f. C., The synthetic-technical development of oseltamivir phosphate Tamiflu™: A race against time. Chimia 2007, 61 (3), 93-99. 3. Vojá č ková , P.; Michalska, L.; Neč as, M.; Shcherbakov, D.; Bö ttger, E. C.; Š poner, J. i.; Š poner, J. E.; Š venda, J. J. J. o. t. A. C. S., Stereocontrolled synthesis of (−)-Bactobolin A. Journal of the American Chemical Society 2020, 142 (16), 7306-7311. 4. Tharra PR, Mikhaylov AA, vejkar J, Gysin M, Hobbie SN, venda J. Short Synthesis of (+)-Actinobolin: Simple Entry to Complex Small-Molecule Inhibitors of Protein Synthesis. Angew Chem Int Ed Engl. 2022 Apr 19;61(17):e202116520. 5. Holmstedt, S.; George, L.; Koivuporras, A.; Valkonen, A.; Candeias, N. R., Deoxygenative Divergent Synthesis: En Route to Quinic Acid Chirons. J Organic Letters 2020, 22 (21), 8370-8375. 6. Holmstedt, S.; Efimov, A.; Candeias, N. R., O, O-Silyl Group Migrations in Quinic Acid Derivatives: An Opportunity for Divergent Synthesis. J Organic Letters 2021, 23 (8), 3083-3087. 7. Gualandi, A.; Nenov, A.; Marchini, M.; Rodeghiero, G.; Conti, I.; Paltanin, E.; Balletti, M.; Ceroni, P.; Garavelli, M.; Cozzi, P. G., Tailored Coumarin Dyes for Photoredox Catalysis: Calculation, Synthesis, and Electronic Properties. J ChemCatChem 2021, 13 (3), 981-989
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