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Nickel‐Catalyzed Asymmetric Hydrogenation of N ‐Sulfonyl Imines
Author(s) -
Li Bowen,
Chen Jianzhong,
Zhang Zhenfeng,
Gridnev Ilya D.,
Zhang Wanbin
Publication year - 2019
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201902576
Subject(s) - catalysis , nickel , catalytic cycle , sulfonyl , asymmetric hydrogenation , salt (chemistry) , chemistry , substrate (aquarium) , ligand (biochemistry) , combinatorial chemistry , enantioselective synthesis , transition metal , organic chemistry , biochemistry , alkyl , oceanography , receptor , geology
An efficient nickel‐catalyzed asymmetric hydrogenation of N ‐ t Bu ‐ 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.