Hydrogen-Evolution Allylic C(sp3)-H Alkylation with Protic C(sp3)-H Bonds via Triplet Synergistic Bronsted Base/Cobalt/Photoredox Catalysis

Transition-metal-catalyzed allylic C(sp(3))-H alkylation with carbon-center nucleophiles is a straightforward approach to C(sp(3))-C(sp(3)) bond formation, which has found widespread application in organic synthesis. However, stoichiometric oxidants are typically required to realize the transformation. Herein, by the triplet synergistic merger of Bri nsted base/cobalt/photoredox catalysis, a mild protocol for the hydrogen-evolution allylic C(sp(3))-H alkylation with protic C(sp(3))-H feedstocks was developed in an oxidant-free manner. This operationally simple method enables direct allylic C(sp(3))-H alkylation of a wide range of branched alpha-olefins with diverse protic C(sp(3))-H feedstocks. The synthetic robustness of this strategy was further demonstrated by the late-stage functionalization of complex molecules and the synthesis of the natural product dihydropallescensin D.

Automated summary

In this study, a mild and operationally simple approach for allylic C(sp(3))-H alkylation without oxidants was developed through the triplet synergistic merger of Brønsted base/cobalt/photoredox catalysis. This strategy enables the direct allylic C(sp(3))-H alkylation of various branched alpha-olefins with protic C(sp(3))-H feedstocks.