Photoredox catalysis

Our studies in photoredox catalysis was initiated by Photoreductive Removal of O-Benzyl Groups from Oxyarene N-Heterocycles Assisted by O-Pyridine–pyridone Tautomerism,  A. Todorov et al J. Org. Chem. 2017, 82, 13756-13767

The study was motivated by the idea whether protonation of pyridine could promote the photoredox process via hydrogen atom transfer (HAT) mechanism.

The same HAT hypothesis made us curious whether similar protonation of nitro-N-heteroaryls could promote Visible-Light-Photocatalyzed Reductions of N-Heterocyclic Nitroaryls to Anilines utilizing Ascorbic Acid as Reductant, A. Todorov at al Org. Lett. 2019, 21, 3764

Current organophotocatalytic trend in the research group was initiated by ”Phenanthrenequinone-Sensitized Photocatalytic Synthesis of Polysubstituted Quinolines from 2-Vinylarylimines” J. Talvitie et al. Org. Lett. 2022, 24, 1, 274.

by exposing that a simple quinone is capable for very efficient photoredox catalysis involving interesting mechanistic route

After making some photoredox catalyzed routine alcohol oxidation with phenanthrenequinone (PQ), we discovered that these processes are most intriguing from mechanistic point of view. Moreover, we made a discovery that by tailoring PQ with electron withdrawing CF3 groups the reaction mechanism can be converted from electron transfer to HAT triggered. Electron-Deficient Phenanthrenequinone Derivative for Photoactivated Hydrogen Atom Transfer Mediated Oxidation of Secondary Alcohols J. talvitie et al ChemPhotoChem, 2023, https://doi.org/10.1002/cptc.202300107

Overall, the “photoquinoidic” catalysis is currently extensively studied in the group and we will update this list soon