Kinetic Studies Prove High Catalytic Activity of a Diene–Rhodium Complex in 1,4‐Addition of Phenylboronic Acid to α,β‐Unsaturated Ketones

In the 1,4‐addition of phenylboronic acid to α,β‐unsaturated ketones, [Rh(OH)(cod)]₂ has a much higher catalytic activity than [Rh(OH)(binap)]₂ (cod=1,5‐cyclooctadiene, binap=2,2′‐bis(diphenylphosphanyl)‐1,1′‐binaphthyl). Kinetic studies revealed that the rate‐determining transmetalation step in the catalytic cycle has a large rate constant when [Rh(OH)(cod)]₂ is used.