Chemistry - A European Journal p. 9911 - 9918 (2012)
Update date:2022-08-05
Topics:
Zhao, Li-Wei
Shi, Hui-Min
Wang, Jiu-Zhao
He, Jing
The use of suitable chiral ligands is an efficient means of producing highly enantioselective transition-metal catalysts. Herein, we report a facile, economic, and effective strategy for the design of chiral ligands that demonstrate enhanced enantioselectivity and catalytic efficacy. Our simple strategy employs naturally occurring or synthetic inorganic nanosheets as huge and rigid planar substituents for, but not limited to, naturally available α-amino-acid ligands; these ligands were successfully used in the vanadium-catalyzed asymmetric epoxidation of allylic alcohols. The crucial role of the inorganic nanosheets as planar substituents in improving the enantioselectivity of the reaction was clearly revealed by relating the observed enantiomeric excess with the distribution of the catalytic centers and the accessibility of the substrate molecules to the catalytic sites. DFT calculations indicated that the LDH layer improved the enantioselectivity by influencing the formation and stability of the catalytic transition states, both in terms of steric resistance and H-bonding interactions. Handy tricks for asymmetric catalysis: The inorganic layer serves as a huge and rigid planar substituent to effectively enhance the enantioselectivity in the vanadium-catalyzed asymmetric epoxidation of allylic alcohols. Copyright
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Doi:10.1021/jo00063a020
(1993)Doi:10.1016/S0040-4039(00)77514-9
(1993)Doi:10.1021/jo00063a043
(1993)Doi:10.1246/bcsj.66.181
(1993)Doi:10.1007/BF02253029
(1997)Doi:10.1080/00397919308009806
(1993)