Catalytic C-Demethylation of Phenols and Anilines Enabled by a Removable Mono-Directing Group
Yibin Xue1, Liyan Kan1, Linda Yiu1
1Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States.
Abstract:
The activation of unstrained nonpolar C-C bonds, such as C(aryl)-C(alkyl) bonds, remains challenging to achieve. Existing catalytic strategies predominantly rely on bidentate chelating directing groups (DGs) or special substrates. Herein, we report a Ru-catalyzed activation of C(aryl)-C(methyl) bonds enabled by a removable mono-DG. By employing a bulky phosphinite or aminophosphine-DG that can be easily installed and removed later, a methyl group at the ortho position of phenols and anilines can be smoothly deleted under the hydrogenolysis condition. This reaction exhibits a broad substrate scope and excellent functional group tolerance. Mechanistic studies suggest that a Ru-hydride species generated in situ is responsible for the C(aryl)-C(methyl) bond activation, with methane identified as a byproduct.
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