Chemoselective Palladium‐Catalyzed Reaction in Aqueous Media: Selectivity in the Reaction of Haloanilines with 1,1‐Dimethylallyl Alcohol

Abstract

Abstract Palladium‐catalyzed reactions of various haloanilines with 1,1‐dimethylallyl alcohol were carried out in the presence of a hydrophilic ligand, 3,3′,3′′‐phosphinidyne tris(benzenesulfonic acid) trisodium salt (TPPTS), or a lipophilic phosphine ligand, 1,1′‐bis(diphenylphosphino)ferrocene (DPPF). The reactions proceeded chemoselectively in aqueous solvent to give C ‐vinylated products under basic conditions or N ‐allylated products under neutral conditions in practical yields (up to 79 %). The use of an aqueous solvent played an important role in this chemoselectivity and allowed the development of a one‐pot synthesis of 3‐methylindole. This chemoselectivity is synthetically useful because the reactive position of haloanilines can be controlled simply by changing the basicity of the reaction medium, which eliminates the need to protect the amino group during the reaction.