Fig. 6: Substrate scope of Ru-catalyzed transfer hydrogenation reactions.
From: Asymmetric hydrogenation of 1,1-diarylethylenes and benzophenones through a relay strategy
Synthesis of compounds bearing a chiral gem-diaryl motif from benzophenones by a sequence involving selective arene exchange and stereoselective asymmetric transfer hydrogenation. Reaction conditions, unless otherwise noted: (1) 1 (0.2 mmol), 2 (0.3 mmol), dioxane (2.0 mL), 80 °C, 24 h. (2) Ru-2 (7 mol%), NaCO2H (2 mmol), DMF (1.0 mL), H2O (0.1 mL), 35 °C, 36 h; then irradiation for 2 h with 440 nm LEDs. Isolated yields were reported. The absolute configurations of 4a, 4e, 4 h and 4 m were S, as determined by comparing their optical rotations with reported data.
