Electrostatic interaction, especially electrostatic attraction, usually plays critical roles in controlling the reactivity and selectivity in catalytic transformations;however, the like-charge repulsion, which is ubiq...Electrostatic interaction, especially electrostatic attraction, usually plays critical roles in controlling the reactivity and selectivity in catalytic transformations;however, the like-charge repulsion, which is ubiquitous in physical systems, is rarely applied in reaction control. Herein we disclosed an unexpected like-charge repulsion induced enantio-control mode in primary aminecatalyzed fluorination reactions with 1-fluoro-2,4,6-trimethylpyridinium triflate. The ionic reaction works favorably in both highly polar(methanol) and non-polar(hexane) solvents, a seldom observed phenomenon in asymmetric catalysis. Erying plot analysis showed that an inversion temperature existed in Me OH, which was explained by the solvent-solute cluster model under different temperatures. Density functional theory(DFT) study and energy decomposition analysis(EDA) verified that the likecharge repulsion takes effect in polar solvent methanol, while in nonpolar solvents, the steric repulsion associated with ion-pair was found to be the major effect for the observed enantioselectivity.展开更多
基金supported by the National Natural Science Foundation of China (22373056, 22031006)the Haihe Laboratory of Sustainable Chemical Transformations (YYJC202113)+1 种基金the National Science & Technology Fundamental Resource Investigation Program of China (2018FY201200)supported by the National Program of Top-notch Young Professionals。
文摘Electrostatic interaction, especially electrostatic attraction, usually plays critical roles in controlling the reactivity and selectivity in catalytic transformations;however, the like-charge repulsion, which is ubiquitous in physical systems, is rarely applied in reaction control. Herein we disclosed an unexpected like-charge repulsion induced enantio-control mode in primary aminecatalyzed fluorination reactions with 1-fluoro-2,4,6-trimethylpyridinium triflate. The ionic reaction works favorably in both highly polar(methanol) and non-polar(hexane) solvents, a seldom observed phenomenon in asymmetric catalysis. Erying plot analysis showed that an inversion temperature existed in Me OH, which was explained by the solvent-solute cluster model under different temperatures. Density functional theory(DFT) study and energy decomposition analysis(EDA) verified that the likecharge repulsion takes effect in polar solvent methanol, while in nonpolar solvents, the steric repulsion associated with ion-pair was found to be the major effect for the observed enantioselectivity.
