Iridium-Catalyzed Asymmetric Hydrogenation of Unfunctionalized Cycloalkenes to Access Chiral 2-Aryl Tetralins
Tierui Pan1,2, Qianjia Yuan2, Defeng Xu1
1School of Pharmacy & School of Biological and Food Engineering, Changzhou University, Changzhou 213164, P. R. China.
Abstract:
The transition-metal catalyzed asymmetric hydrogenation of unfunctionalized alkenes is challenging. Herein, we report an efficient iridium-catalyzed asymmetric hydrogenation of unfunctionalized cycloalkenes, delivering chiral 2-aryl tetralins in excellent yields and with moderate to excellent enantioselectivities. The reaction can be performed on a gram-scale with a low catalyst loading (S/C = 1000), and the reduced product was obtained without erosion of the enantioselectivity. Deuterium experiments indicated that the C═C bond in the substrate is hydrogenated directly without isomerization.
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