Aldehydes as Photoremovable Directing Groups: Synthesis of Pyrazoles by a Photocatalyzed [3+2] Cycloaddition/Norrish Type Fragmentation Sequence
Ana Pascual-Escudero, Laura Ortiz-Rojano, Silvia Simón-Fuente, Javier Adrio* and María Ribagorda*
*Departamento de Química Orgánica, Facultad de Ciencias,
Universidad Autónoma de Madrid, 28049 Madrid, Spain, Email: javier.adrio
uam.es,
maria.ribagordauam.es
A. Pascual-Escudero, L. Ortiz-Rojano, S. Simón-Fuente, J. Adrio, M. Ribagorda, Org. Lett., 2021, 23, 4903-4908.
DOI: 10.1021/acs.orglett.1c01665
see article for more reactions
Abstract
A photoclick cycloaddition followed by a photocatalyzed oxidative deformylation reaction enable a straightforward regioselective synthesis of pyrazoles. This protocol includes an unprecedented photoredox-catalyzed Norrish type fragmentation under green-light irradiation and offers the use of α,β-unsaturated aldehydes as synthetic equivalents of alkynes.
see article for more examples
proposed mechanism
While ads financed 62% of the published abstracts in 2024, donations allowed us to publish additional 12%. 26% of the abstracts have been published voluntarly. If you kindly donate, we can publish more freely accessible information and help the chemical community even more:
If you don't like pawalls or a flood of more and more advertising, then you can send a clear signal here!
Key Words
pyrazoles, photochemistry
ID: J54-Y2021
