N-Benzylation/Benzylic C-H Amidation Cascade by the ( eta super(3)-Benzyl)palladium System in Aqueous Media: An Effective Pathway for the Direct Construction of 3-Phenyl-3,4-dihydro-(2H)-1,2,4-benzothiadiazine 1,1-Dioxides

We demonstrate a unique strategy for a benzylation/benzylic C-H amidation cascade reaction by the ( eta super(3)-benzyl)palladium system derived from a palladium catalyst and benzyl alcohol. This tandem process is devised as a new synthetic route for 3-phenyl-3,4-dihydro-(2H)-1,2,4-benzothiadiazine-1,1-dioxide. Water plays an important role for the smooth generation of the ( eta super(3)-benzyl)palladium species, and a bis-benzylated Pd(II) intermediate would be formed in our catalytic system. Atom economical processes such as benzylic C-H activation, cascade reactions and chemoselective reactions in aqueous media have been developed.