Mechanistic Insight into the Photoredox-Nickel-HAT Triple Catalyzed Arylation and Alkylation of α-Amino Csp3–H Bonds
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ArticleAuthors
Maity, Bholanath
Zhu, Chen

Yue, Huifeng
Huang, Long
Harb, Moussab

Minenkov, Yury
Rueping, Magnus

Cavallo, Luigi

KAUST Department
KAUST Catalysis Center (KCC)Physical Science and Engineering (PSE) Division
Chemical Science Program
Date
2020-09-09Online Publication Date
2020-09-09Print Publication Date
2020-10-07Embargo End Date
2021-09-09Permanent link to this record
http://hdl.handle.net/10754/665080
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We report here a comprehensive computational analysis of the mechanisms of the photoredox-nickel-HAT (HAT: hydrogen atom transfer) catalyzed arylation and alkylation of α-amino Csp3–H bonds developed by MacMillan and coworkers. Different alternatives for the three catalytic cycles were tested to identify unambiguously the operative reaction mechanism. Our analysis indicated that the IrIII photoredox catalyst, upon irradiation with visible light, can be either reduced or oxidized by the HAT and nickel catalysts, respectively, indicating that both reductive and oxidative quenching catalytic cycles can be operative, although the reductive cycle is favored. Our analysis of the HAT cycle indicated that activation of a α-amino Csp3‒H bond of the substrate is facile and selective relative to activation of a β-amino Csp3‒H bond. Finally, our analysis of the nickel cycle indicated that both arylation and alkylation of α-amino Csp3–H bonds occurs via the sequence of nickel oxidation states NiI-NiII-NiI-NiIII, and of elementary steps: radical addition-SET-oxidative addition-reductive elimination.Citation
Maity, B., Zhu, C., Yue, H., Huang, L., Harb, M., Minenkov, Y., … Cavallo, L. (2020). Mechanistic Insight into the Photoredox-Nickel-HAT Triple Catalyzed Arylation and Alkylation of α-Amino Csp3–H Bonds. Journal of the American Chemical Society. doi:10.1021/jacs.0c05010Sponsors
We acknowledge King Abdullah University of Science and Technology (KAUST) for support and the KAUST Supercomputing Laboratory for providing computational resources of the supercomputer Shaheen II.Publisher
American Chemical Society (ACS)Additional Links
https://pubs.acs.org/doi/10.1021/jacs.0c05010ae974a485f413a2113503eed53cd6c53
10.1021/jacs.0c05010