Palladium-catalyzed benzylic C(sp3)–H arylation of o-alkylbenzaldehydes

Abstract The palladium-catalyzed benzylic C(sp3)–H arylation of o-alkylbenzaldehyde derivatives was achieved utilizing 2-dimethylaminoethylamine as a novel transient directing group. The γ-C(sp3)–H arylation reaction efficiently afforded a variety of arylated o-alkylbenzaldehydes and polycyclic aromatic hydrocarbons (PAHs) in one pot, exhibiting high functional group tolerance with broad substrate scope. The aliphatic diamine auxiliary represents a simple, inexpensive, readily available, and removable directing group for C H activation. The resultant o-benzylbenzaldehyde products could be diversely transformed into potentially important synthetic intermediates under mild conditions.