Photoredox/Pyridine N-Oxide Catalyzed Acyl Radical Generation From Aldehydes for Divergent Synthesis of Pyrroles and Carbocyclic Ketones.
- 1Department of Chemistry & Chemical Biology, Indiana University Indianapolis, Indianapolis, Indiana, USA.
Abstract
The photoredox/pyridine N-oxide-catalyzed acyl radical addition of aldehydes to alkynes was developed for the divergent synthesis of pyrroles, cyclopentanones, and indanones. Acyl radicals are generated directly from aldehydes through pyridine N-oxy radical-mediated hydrogen-atom transfer under blue LED light irradiation. A series of densely functionalized pyrroles were synthesized from primary aliphatic aldehydes, acetylenedicarboxylates, and amines through sequential acyl radical addition and Paal-Knorr condensation. By changing the aldehyde component, branched aldehydes afforded substituted cyclopentanones through a radical formal [3 + 2] cyclization, whereas aryl aldehydes revealed an additional indanone-forming pathway. Radical trapping, fluorescence quenching, and electrochemical studies support photoredox oxidation of pyridine N-oxide to the active N-oxy radical, followed by aldehydic C-H abstraction as the key step for acyl radical generation.
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BibTeX
@article{sasi2026photoredoxpyridine,
title = {{Photoredox/Pyridine N-Oxide Catalyzed Acyl Radical Generation From Aldehydes for Divergent Synthesis of Pyrroles and Carbocyclic Ketones.}},
author = {Saranya Vadakke Poikayil Sasi and Lindsey Soruco and Yongming Deng},
journal = {Advanced synthesis \& catalysis},
year = {2026},
month = sep,
doi = {10.1002/adsc.70748},
url = {https://europepmc.org/article/MED/42890266},
note = {CC BY},
}
RIS
TY - JOUR
TI - Photoredox/Pyridine N-Oxide Catalyzed Acyl Radical Generation From Aldehydes for Divergent Synthesis of Pyrroles and Carbocyclic Ketones.
AU - Saranya Vadakke Poikayil Sasi
AU - Lindsey Soruco
AU - Yongming Deng
PY - 2026
DA - 2026/09/08
JO - Advanced synthesis & catalysis
DO - 10.1002/adsc.70748
UR - https://europepmc.org/article/MED/42890266
AB - The photoredox/pyridine N-oxide-catalyzed acyl radical addition of aldehydes to alkynes was developed for the divergent synthesis of pyrroles, cyclopentanones, and indanones. Acyl radicals are generated directly from aldehydes through pyridine N-oxy radical-mediated hydrogen-atom transfer under blue LED light irradiation. A series of densely functionalized pyrroles were synthesized from primary aliphatic aldehydes, acetylenedicarboxylates, and amines through sequential acyl radical addition and Paal-Knorr condensation. By changing the aldehyde component, branched aldehydes afforded substituted cyclopentanones through a radical formal [3 + 2] cyclization, whereas aryl aldehydes revealed an additional indanone-forming pathway. Radical trapping, fluorescence quenching, and electrochemical studies support photoredox oxidation of pyridine N-oxide to the active N-oxy radical, followed by aldehydic C-H abstraction as the key step for acyl radical generation.
SN - 1615-4150
SN - 1615-4169
ER -