Alkene Dialkylation via Triple Radical Sorting

The development of bimolecular homolytic substitution (SH2) catalysis has expanded cross-coupling logic by enabling the selective merger of any primary radical with any secondary or tertiary radical via a radical sorting mechanism. SH2 catalysis can be used to merge common feedstock chemicals—such as alcohols, acids, and halides—in any permutation for the construction of a single C(sp3)–C(sp3) bond. The ability to sort these two distinct radicals across commercially available alkenes in a three-component manner would enable the simultaneous construction of two C(sp3)–C(sp3) bonds, greatly accelerating access to drug-like chemical space. However, the simultaneous in situ formation of electrophilic and primary nucleophilic radicals in the presence of unactivated alkenes is problematic, typically leading to statistical radical recombination, hydrogen atom transfer, disproportionation, and other deleterious pathways. Herein, we report the use of bimolecular homolytic substitution catalysis to sort an electrophilic radical and a nucleophilic radical across an unactivated alkene. This reaction involves the in situ formation of three distinct radical species, which are then differentiated by size and electronics, allowing for regioselective formation of desired dialkylated products. This work accelerates access to pharmaceutically relevant C(sp3)-rich molecules and defines a novel mechanistic paradigm for alkene dialkylation.