Room Temperature Coupling of Aryldiazoacetates with Boronic Acids Enhanced by Blue Light Irradiation

• Published in: Chemistry : a European journal 2020-05, Vol.26 (25), p.5648-5653
• Main Authors: Silva, Amanda F., Afonso, Marco A. S., Cormanich, Rodrigo A., Jurberg, Igor D.
• Format: Article
• Language: English
• Subjects: Acids; aryldiazoacetates; Biological activity; blue light; boronic acids; Carbenes; Chemistry; Coupling; Coupling (molecular); cross-coupling; Functional groups; Intermediates; Irradiation; Light irradiation; Photochemical reactions; Photochemicals; photochemistry; Room temperature
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201905812

A visible‐light‐promoted photochemical protocol is reported for the coupling of aryldiazoacetates with boronic acids. This photochemical reaction shows great enhancement compared to the same protocol performed in the absence of light. Except for a few cases, the room temperature coupling in the dark (thermal process) generally does not work. When it does, it is likely to also involve free carbenes as key intermediates. Alternatively, photochemical reactions show a broad scope, can be performed under air and tolerate a wide variety of functional groups. Reaction‐evolution monitoring, DFT calculations and control experiments have been used to evaluate the main aspects of this intricate mechanistic scenario. Biologically active molecules Adiphenine, Benactyzine and Aprophen have been prepared as examples of synthetic applications. Lights on! A visible‐light‐promoted protocol is reported for the coupling of aryldiazoacetates with boronic acids. This photochemical reaction shows great enhancement compared to the same protocol performed in the absence of light. Mechanistic studies including control experiments, DFT calculations and reaction‐evolution monitoring; as well as synthetic applications have been performed showcasing a rich panorama of chemical reactivity.