Rhodium-Catalyzed ortho-Bromination of O-Phenyl Carbamates Accelerated by a Secondary Amide-Pendant Cyclopentadienyl Ligand

Abstract

It has been established that a newly developed cyclopentadienyl rhodium(III) [Cp^A Rh^III ] complex, bearing an acidic secondary amide moiety on the Cp ring, is able to catalyze the ortho-bromination of O-phenyl carbamates with N-bromosuccinimide (NBS) at room temperature. The presence of the acidic secondary amide moiety on the Cp^A ligand accelerates the bromination by the hydrogen bond between the acidic NH group of the Cp^A ligand and the carbonyl group of NBS.

Keywords: cyclopentadienyl ligand; hydrogen bond; ortho-bromination; phenyl carbamates; rhodium.