Pd-Catalyzed, Highly Selective C(sp²)-Br Bond Coupling Reactions of o-(or m-, or p-) Chloromethyl Bromobenzene with Arylboronic Acids.

Highly selective C(sp²)-C(sp²) cross-coupling of dihalogenated hydrocarbons comprising C(sp²)-Br and C(sp³)-Cl bonds with arylboronic acids is reported. This highly selective coupling reaction of the C(sp²)-Br bond is successfully achieved using Pd(OAc)₂ and PCy₃·HBF₄ as the palladium source and ligand, respectively. A series of chloromethyl-1,1'-biphenyl compounds are obtained in moderate-to-excellent yields. Moreover, this protocol can be extended to the one-pot dual arylation of 1-bromo-4-(chloromethyl)benzene with two arylboronic acids, leading to diverse unsymmetrical 4-benzyl-1,1'-biphenyl derivatives.