Broad-Scope Amination of Aryl Sulfamates Catalyzed by a Palladium Phosphine Complex

Among phenol-derived
electrophiles, aryl sulfamates are attractive
substrates since they can be employed as directing groups for C–H
functionalization prior to catalysis. However, their use in C–N
coupling is limited only to Ni catalysis. Here, we describe a Pd-based
catalyst with a broad scope for the amination of aryl sulfamates.
We show that the N-methyl-2-aminobiphenyl palladacycle
supported by the PCyp2ArXyl2 ligand (Cyp = cyclopentyl;
ArXyl2 = 2,6-bis­(2,6-dimethylphenyl)­phenyl) efficiently
catalyzes the C–N coupling of aryl sulfamates with a variety
of nitrogen nucleophiles, including anilines, primary and secondary
alkyl amines, heteroaryl amines, N-heterocycles,
and primary amides. DFT calculations support that the oxidative addition
of the aryl sulfamate is the rate-determining step. The C–N
coupling takes place through a cationic pathway in the polar protic
medium.