Various methods that use a photocatalyst for electron transfer between an organic substrate and a transition metal catalyst have been established. While triplet sensitization of organic substrates via energy transfer from photocatalysts has been demonstrated, the sensitization of transition metal catalysts is still in its infancy. Here, we describe the selective alkylation of C(sp3)–H bonds via triplet sensitization of nickel catalytic intermediates with a thorough elucidation of its reaction mechanism. Exergonic Dexter energy transfer from an iridium photosensitizer promotes the nickel catalyst to the triplet state, thus enabling C–H functionalization via the release of bromine radical. Computational studies and transient absorption experiments support that the reaction proceeds via the formation of triplet states of the organometallic nickel catalyst by energy transfer.
Bibliographical noteFunding Information:
This publication is based upon work supported by the King Abdullah University of Science and Technology (KAUST), Office of Sponsored Research (OSR) under Award No. OSR-CRG2019-4025. The authors acknowledge the KAUST Supercomputing Laboratory for providing computational resources of the supercomputer Shaheen II.
© 2022, The Author(s).
ASJC Scopus subject areas
- General Chemistry
- General Biochemistry, Genetics and Molecular Biology
- General Physics and Astronomy