Based on the reported data, in the initial phase of our study, a model 2-phenyl Zincke imine 2, obtained from 2-phenylpyridine (1), was reacted with an amino-pyridinium salt in the presence of fac-Ir(ppy)3 under blue light irradiation to give, after the consecutive ring closure, desired product 3 (for details see SI), but in a low yield (Scheme 2A). DFT calculations revealed that the formation of C-N bonds at the C5 position should be predominant over the C3 position due to the lower transition state energy (Scheme 2B). Thorough optimization studies enabled a significant improvement in the yield (Table , entry 1). The optimal conditions are as follow: under an argon atmosphere, a mixture of 2-phenyl Zincke imine 2 (1 equiv.) and N-amino-pyridinium salt (1.5 equiv.) in the presence of fac-Ir(ppy)3 (2 mol%) in MeCN/DMSO mixture (v/v 1:1) (0.006 M) was irradiated (LED, 405 nm) at 0 °C for 24 h. The subsequent treatment with saturated NH4OAc in EtOH in a one-pot manner gave the desired rearomatized C3-amido-pyridine 3 as a mixture of two regioisomers 3a and 3b in 99% yield (5:1, entry 1). The use of either sole DMSO or MeCN diminished the yield (entries 2 and 3). Previous studies have demonstrated that reduction of N-amino-pyridinium salts to N-centered radicals by Ir(III) in the excited state involving single electron transfer (SET) can be performed under blue LED irradiation. Intriguingly, in our case, the reaction yield decreased significantly to 16%, probably due to the strong absorption around 450 nm in the UV-Vis spectrum of Zincke imine 2 (entry 4, Figure ). As a result, violet light (405 nm) irradiation proved a crucial factor for the excitation of the Ir-catalyst and thus generation of amidyl radicals in the presence of Zincke imines. The use of a slight excess of the pyridinium salt (1.5 equiv.) was required to successfully complete the reaction (entry 5). Diluted conditions were deemed necessary as a significant decrease in the yield was observed in the case of concentrated solutions (entry 6). Control experiments without the photocatalyst or light (entries 7-9) clearly indicated that the reaction is a photochemically induced process. The scope with respect to the pyridine was then examined (Scheme 3). 2-Phenyl-substituted pyridines bearing electrondonating groups (EDG) (e.g., methoxy, methyl) on the phenyl ring are well tolerated giving products 4-12 in high yields, though the yield diminishes when substituents impose a steric hindrance around newly forming bond, for example two methoxy groups at ortho-positions (7a). In these cases, harsher conditions are required for the effective ring closure (using a microwave with higher temperature; for details, see SI). Despite the steric hindrance at the 2-position, 2-methylthio-substituted (8a) pyridine gives the desired product in 88% yield and high regioselectivity. Other 2-arlyl derivatives, such as biphenyls (13-15), phenanthrene (17) and-, pyrene (18) furnishes similar results, but we observed a reduced yield for the naphthalene derivative (16) due to incomplete conversion of the reaction. On the other hand, electron-withdrawing groups (e. g., -CF3, difluoro) are not only well tolerated, but they also have a beneficial impact on the regioselectivity of the reaction. For example, the reaction with 2-(4-nitrophenyl)pyridine affords exclusively product 20a in 98% yield with excellent regioselectivity. 2-Heteroaryl substituted pyridines provide amidated products 24-29 in satisfactory yields (35-86%). The low yield for the substrate bearing the N-Boc-pyrrole moiety results from partial deprotection of the carbamate group under the acidic condition. Furthermore, the influence of alkyl groups at position 2 was examined. For a series of 2-alkylpyridines (methyl, ethyl, hexyl, and benzyl), decreased yields were observed under standard conditions. We fine-tuned the reaction conditions and found the exclusive use of MeCN, alongside a higher power of the light source effectively increased the efficacy of the C3amidation reaction with 2-alkylsubstituents (for details, see SI). Interestingly, the regioselectivity switches, in this case an amidyl radical attacks Zincke imine preferentially at the β position therefore, the resultant pyridine bears substituents at position 2 and 3 in contrast to 2-phenylpyridine, for which they occupy positions 3 and 5. An exception are isopropyl and methoxysubstituted benzyl derivatives that form amidated products 33 and 35 with almost no selectivity.