In light of these observations and based on the reported Single Electron Transfer (SET) mechanism of EYNa2, we propose the ensuing catalytic cycle (see Figure ). Upon absorption of visible light, the triplet excited state of EYNa2 is reductively quenched by the sacrificial electron donor HE to generate HE +‧ . Following the findings of Overmann and König, the redox-active ester is subsequently reduced by the EYNa2 radical anion, thereby completing the catalytic cycle and yielding the nucleophilic alkyl radical 66 upon decarboxylation. The emergent alkyl radical is then captured by the electrophilic site of sulfonyl hydrazone, resulting in the formation of the hydrazinyl radical intermediate 67. Finally, a plausible Hydrogen Atom Transfer (HAT) step from HE +‧ or neutral HE to 67 is considered, generating the pyridium co-product 68 and the targeted product 69.