Ligand-Enabled Sequential C(sp 3 )-H and C(sp 2 )-H Diolefination Reaction via Palladium Catalyst.

Palladium-catalyzed sequential C(sp 3 )-H and C(sp 2 )-H bond diolefination reaction of o -toluidine has been realized for the first time using acetyl-protected aminoethyl phenyl thioether ligands. This novel reaction allows for preparation of the conjugated diene structure via an immediate second olefination on the basis of the first C(sp 3 )-H olefination in one pot. Various triflyl-protected anilines and acrylates were used as coupling partners elegantly. Furthermore, the unpurified diolefination products can be easily converted to tetrahydroquinoline derivatives.