Cobalt-Hydride Catalyzed Alkene-Carboxylate Transposition (ACT) of Allyl Carboxylates via 1,2-Radical Migration (RaM)

The Alkene-Carboxylate Transposition (ACT) of allyl carboxylates is one of the most atom-economic and synthetically reliable transformations in organic chemistry, as allyl carboxylates are versatile synthetic intermediates. Classic ACT trans-formations, including 3,3-sigmatropic rearrangement and transition metal-catalyzed allylic rearrangement, typically yield 1,2-alkene/1,3-acyloxy shifted products through a two-electron process. However, position-altered ACT to produce distinct 1,3-alkene/1,2-acyloxy shifted products has remained elusive. Here, we report the first cobalt-hydride catalyzed ACT of allyl carboxylates, enabling access to these unprecedented 1,3-alkene/1,2-acyloxy shifted products via a 1,2-radical migration (RaM) strategy. This transformation demonstrates broad functional group tolerance, is suitable for late-stage modification of complex molecules, and is amenable to gram-scale synthesis. It also expands the reaction profiles of both allyl carbox-ylates and cobalt catalysis. Preliminary experimental and computational studies suggest a mechanism involving metal-hydride hydrogen atom transfer (MHAT) and 1,2-RaM process. This reaction is expected to serve as the basis for the devel-opment of versatile Co-H catalyzed transformations of allyl carboxylates, generating a wide array of valuable building blocks for synthetic, medicinal, and materials chemistry.