溶剂效应对 Ir 催化的不对称氢化反应对映选择性影响的理论研究

This study investigates the transformation mechanism of an efficient solvent-controlled Ir-catalyzed enantioselective hydrogenation system for quinoxalines through rational mechanistic hypotheses combined with density functional theory (DFT) calculations. Experimental results demonstrate that this catalytic system, under additive-free conditions, successfully produces both enantiomers of 2-aryl tetrahydroquinoxalines by simply switching the reaction solvent. Specifically, the product obtained in the toluene/dioxane solvent system has an R-configuration with an ee value of 98%, while the product in the ethanol solvent system exhibits an S-configuration with an ee value of 93%. The objective of this work is to combine mechanistic experiments with DFT calculations to elucidate the role of solvents in modulating the enantioselectivity of this catalytic system and to provide a theoretical foundation and guidance for the development of other solvent-controlled enantioselective catalytic systems.