Highly Active and Enantioselective Rhodium‐Catalyzed Asymmetric 1,4‐Addition of Arylboronic Acid to α,β‐ Unsaturated Ketone by using Electron‐Poor MeO‐F 12 ‐BIPHEP

The asymmetric 1,4‐addition of phenylboronic acid to cyclohexenone were performed by using a low amount of rhodium/( R )‐(6,6′‐dimethoxybiphenyl‐2,2′‐diyl)bis[bis(3,4,5‐trifluorophenyl)phosphine] (MeO‐F 12 ‐BIPHEP) catalyst. Because the catalyst shows thermal resistance at 100 °C, up to 0.00025 mol% Rh catalyst showed good catalytic activity. The highest turnover frequency (TOF) and turnover number (TON) observed were 53,000 h −1 and 320,000, respectively. The enantioselectivities of the products were maintained at a high level of 98% ee in these reactions. The Eyring plots gave the following kinetic parameters (ΔΔ H ≠ =−4.0±0.1 kcal mol −1 and ΔΔ S ≠ =−1.3±0.3 cal mol −1  K −1 ), indicating that the entropy contribution is relatively small. Both the result and consideration of the transition state in the insertion step at the B3LYP/6‐31G(d) [LANL2DZ for rhodium] levels indicated that the less σ‐donating electron‐poor ( R )‐MeO‐F 12 ‐BIPHEP could be creating a rigid chiral environment around the rhodium catalyst even at high temperature.