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.