Photoinduced, Copper-Catalyzed Decarboxylative C–N Coupling to Generate Protected Amines: An Alternative to the Curtius Rearrangement
Abstract
The Curtius rearrangement is a classic, powerful method for converting carboxylic acids into protected amines, but its widespread use is impeded by safety issues (the need to handle azides). We have developed an alternative to the Curtius rearrangement that employs a copper catalyst in combination with blue-LED irradiation to achieve the decarboxylative coupling of aliphatic carboxylic acid derivatives (specifically, readily available N-hydroxyphthalimide esters) to afford protected amines under mild conditions. This C–N bond-forming process is compatible with a wide array of functional groups, including an alcohol, aldehyde, epoxide, indole, nitroalkane, and sulfide. Control reactions and mechanistic studies are consistent with the hypothesis that copper species are engaged in both the photochemistry and the key bond-forming step, which occurs through out-of-cage coupling of an alkyl radical.
Additional Information
© 2017 American Chemical Society. Received: July 19, 2017; Published: August 25, 2017. Support has been provided by Amgen and by the National Institutes of Health (NIGMS: R01-109194). We thank Jun Myun Ahn, Dr. Victor J. Cee, Bradley J. Gorsline, Carson D. Matier, Dr. Paul H. Oyala (Caltech EPR facility, supported by NSF-1531940), and Dr. Haolin Yin for assistance and helpful discussions. The authors declare no competing financial interest.Attached Files
Accepted Version - nihms905801.pdf
Supplemental Material - ja7b07546_si_001.pdf
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Additional details
- PMCID
- PMC5624330
- Eprint ID
- 80847
- DOI
- 10.1021/jacs.7b07546
- Resolver ID
- CaltechAUTHORS:20170828-124616088
- Amgen
- NIH
- R01-109194
- NSF
- CHE-1531940
- Created
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2017-08-28Created from EPrint's datestamp field
- Updated
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2022-03-23Created from EPrint's last_modified field