Photo-Induced Pyridylic C(sp³)–H Alkylation with Unactivated Alkenes Enabled by Hydrogen Atom Transfer/Lewis Acid Cocatalysis

Radical hydroalkylation of alkenes represents an ideal approach for C(sp3)–C(sp3) bond formation. However, radical precursors have been substantially limited due to the sluggish nature of less electrophilic carbon-centered radicals to participate in addition step toward unactivated alkenes. Herein, we demonstrate that this inherent limitation can be overcome by the use of a Lewis acid catalyst. This cocatalytic system enables the hitherto elusive radical C(sp3)–C(sp3) bond formation between pyridylacetates and unactivated alkenes to generate medically relevant valuable products. Computational studies support that the formation of a Lewis pair with the substrates is crucial to lower the energy of the transition state for the rate-determining radical addition step.