Photoredox-Catalyzed Hydroalkylation of C(sp3)-H Acids
Avery O Morris1, Tegan E O'Brien1, Louis Barriault1
1Center for Catalysis Research and Innovation, Department of Chemistry and Biomolecular Sciences, University of Ottawa, 10 Marie-Curie, Ottawa, K1N 6N5, Canada.
Abstract:
We present a detailed study on a photoredox catalysis platform that directly engages 1,3-dicarbonyl C(sp3)-H acids toward radical reactions. This platform enables redox-neutral hydroalkylation and cross-coupling, as well as oxidative transformations that demonstrably improve on the prior state of the art. Herein, we present interrogations of the underlying catalytic cycle and mechanism for this platform through kinetic, thermodynamic, and computational studies. The present investigations also demonstrate the key role of lithium trifluoroacetate under complementary Ce-containing and Ce-free photoredox conditions to enable ligand-to-metal charge transfer (LMCT) or multi-site proton-coupled electron transfer (MS-PCET) activations, respectively.
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