Aerobic, transition-metal-free, direct, and regiospecific mono-α-arylation of ketones: synthesis and mechanism by DFT calculations.

We disclose a facile, aerobic, transition-metal-free, direct, and regiospecific mono-α-arylation of ketones to yield aryl benzyl and (cyclo)alkyl benzyl ketones with substitution patterns that are currently inaccessible or challenging to prepare using conventional methods. The transformation is operationally simple, scalable, and environmentally friendly. There is no need for pre-functionalization (i.e., α-halogenation or silyl enol ether formation) or the use of specialized arylating agents (i.e., diaryliodonium salts). DFT calculations suggest that the in situ-generated enolate undergoes direct C-C bond formation with the nitroarene followed by regioselective O2-mediated C-H oxidation.