Photocatalyzed (3+2) Cycloaddition for the Dearomatization of Electron-Poor Arenes under Flow Conditions.

Chemistry

Univ Rouen Normandie, INSA Rouen Normandie, CNRS, Normandie Univ, COBRA, 76000, Rouen, France.

Published: September 2023


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Article Abstract

The photocatalyzed dearomative reaction between various electron-deficient aromatic compounds and a non-stabilized azomethine ylide is successfully performed in a flow system. Whereas the use of supported eosin as organic photocatalyst exhibits limited efficiency, turning to the soluble Rose Bengal allows to transform a broad range of substrates from hetarenes (indole, benzofuran, quinoline, pyridine) to naphthalenes and benzenes. This photocatalyzed (3+2) dearomative cycloaddition under green light irradiation provides a simple and efficient access to tridimensional pyrrolidino scaffolds with a tetrasubstituted carbon center at ring junction and can be performed in the friendly ethyl acetate. Computational studies support the mechanism involving azomethine ylide as reactive species toward the electron-poor arene.

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http://dx.doi.org/10.1002/chem.202301567DOI Listing

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