Palladium-Catalyzed ortho C-H Arylation of Benzaldehydes Using ortho-Sulfinyl Aniline as Transient Auxiliary.

A PdII -catalyzed ortho-(Csp2 )-H arylation reaction of benzaldehydes using a catalytic amount of 2-(methylsulfinyl)aniline as transient auxiliary was developed. This reaction is compatible with a broad range of benzaldehyde and aryl iodide substrates. Compared with other related reaction systems, an excellent regioselectivity for ortho-C(sp2 )-H bonds over benzylic C(sp3 )-H bonds was obtained for ortho-alkyl-benzaldehyde substrates.