Strategic Application and Transformation of <i>ortho</i>-Disubstituted Phenyl and Cyclopropyl Ketones To Expand the Scope of Hydrogen Borrowing Catalysis

The application of an iridium-catalyzed hydrogen borrowing process to enable the formation of α-branched ketones with higher alcohols is described. In order to facilitate this reaction, <i>ortho</i>-disubstituted phenyl and cyclopropyl ketones were recognized as crucial structural motifs for C–C bond formation. Having optimized the key catalysis step, the <i>ortho</i>-disubstituted phenyl products could be further manipulated by a retro-Friedel–Crafts acylation reaction to produce synthetically useful carboxylic acid derivatives. In contrast, the cyclopropyl ketones underwent homoconjugate addition with several nucleophiles to provide further functionalized branched ketone products