Ligand-Enabled Room-Temperature Three-Component Strategy for Mono-α-arylation of Acetone with Cyclic Diaryliodonium Salts and Alkenes

Selective
mono-α-arylation of the simplest ketone, acetone,
is a highly sought-after yet challenging transformation. Herein, we
present a Pd-catalyzed three-component cascade approach that achieves
mono-α-arylation of acetone at room temperature. The ligand
was crucial in accomplishing the reaction at room temperature. This
methodology enabled a diverse range of difunctionalized biarylated
products in good to excellent yields, accomplished by reacting cyclic
diaryliodoniums with alkenes and acetone. Mechanistic studies indicate
that alkenylation plays a crucial role in α-arylation of acetone,
likely stabilizing the Pd complex and enabling the cascade reaction
with acetone. A gram-scale reaction and further synthetic manipulations
have been demonstrated.