Shuttle arylation by Rh(I) catalyzed reversible carbon-carbon bond activation of unstrained alcohols

The advent of transfer hydrogenation and borrowing hydrogen reactions paved the way to manipulate simple alcohols in previously unthinkable manners and circumvented the need for hydrogen gas. Analogously, transfer hydrocarbylation could greatly increase the versatility of tertiary alcohols. However, this reaction remains unexplored because of the challenges associated with the catalytic cleavage of unactivated C-C bonds. Herein, we report a rhodium(I)-catalyzed shuttle arylation cleaving the C(sp(2))-C(sp(3)) bond in unstrained triaryl alcohols via a redox-neutral beta-carbon elimination mechanism. A selective transfer hydrocarbylation of substituted (hetero)aryl groups from tertiary alcohols to ketones was realized, employing benign alcohols as latent C-nucleophiles. All preliminary mechanistic experiments support a reversible b-carbon elimination/migratory insertion mechanism. In a broader context, this novel reactivity offers a new platform for the manipulation of tertiary alcohols in catalysis.

Automated summary

The development of transfer hydrogenation and borrowing hydrogen reactions has allowed for new possibilities in manipulating simple alcohols, while transfer hydrocarbylation can increase the versatility of tertiary alcohols. A novel catalytic method was reported for transfer hydrocarbylation, which involves a redox-neutral beta-carbon elimination mechanism. The experimental evidence supports the feasibility of this method for manipulating tertiary alcohols in catalysis.