Volume 58, Issue 22 pp. 7329-7334
Communication

Nickel-Catalyzed Asymmetric Hydrogenation of N-Sulfonyl Imines

Bowen Li

Bowen Li

Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 P. R. China

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Dr. Jianzhong Chen

Dr. Jianzhong Chen

Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 P. R. China

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Dr. Zhenfeng Zhang

Dr. Zhenfeng Zhang

Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 P. R. China

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Prof. Ilya D. Gridnev

Prof. Ilya D. Gridnev

Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, 9808578 Japan

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Prof. Wanbin Zhang

Corresponding Author

Prof. Wanbin Zhang

Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 P. R. China

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First published: 28 March 2019
Citations: 161

Graphical Abstract

The first Ni-catalyzed asymmetric hydrogenation of N-sulfonyl imines using H2 gas as a hydrogen source has been realized with excellent enantioselectivity. The presence of an excess of the nickel salt, with respect to the ligand, promotes the formation of the active Ni catalyst. The reaction features a wide substrate scope, low catalyst loading, and convenient removal of the protecting group.

Abstract

An efficient nickel-catalyzed asymmetric hydrogenation of N-tBu-sulfonyl imines was developed with excellent yields and enantioselectivities using (R,R)-QuinoxP* as a chiral ligand. The use of a much lower catalyst loading (0.0095 mol %, S/C=10500) represents the highest catalytic activity for the Ni-catalyzed asymmetric hydrogenations reported so far. Mechanistic studies suggest that a coordination equilibrium exists between the nickel salt and its complex, and that excess nickel salt promotes the formation of the active Ni-complex, and therefore improved the efficiency of the hydrogenation. The catalytic cycle was also investigated by calculations to determine the origin of the enantioselectivity. An extensive network of numerous weak attractive interactions was found to exist between the catalyst and substrate in the transition state and may also contribute to the high catalytic activity.

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