Co(III)-Catalyzed Dual Carbon-Coupling of Tertiary Allylic Alcohols via Carbon-Skeleton Rearrangement

A Co(III)-catalyzed dual C-C coupling of sterically hindered tertiary allylic alcohols (TAA) with aldehydes via carbon-skeleton rearrangement has been developed. This transformation features a cascade 1,3-aryl transposition and highly regioselective cross-coupling at the C2- and C3- positions of TAA. The combination of experimental and computational studies revealed the synergetic mechanism of Co(III)-catalysts and B(C₆F₅)₃ to enable β-aryl elimination and direct selective trapping of reactive intermediates.