Cobalt-Catalyzed, N-H Imine-Directed Arene C-H Benzylation with Benzyl Phosphates

A cobalt-catalyzed ortho-C-H benzylation reaction of pivalophenone N-H imines with benzyl phosphates is reported. The reaction is promoted at room temperature by a ternary catalytic system comprising Co(acac)(3), a pyridylphosphine ligand, and a Grignard reagent and tolerates a series of substituted pivalophenone imines and benzyl phosphates moderate yields.