450368-91-9Relevant articles and documents
Pd-Catalyzed Asymmetric Allylic Substitution Annulation Using Enolizable Ketimines as Nucleophiles: An Alternative Approach to Chiral Tetrahydroindoles
Xu, Kai,Ye, Jianxun,Liu, Hao,Shen, Jiefeng,Liu, Delong,Zhang, Wanbin
, p. 2059 - 2069 (2020)
A synthesis of chiral tetrahydroindoles has been developed via a Pd-catalyzed asymmetric allylic substitution annulation using unstable enolizable ketimines as nucleophiles and our previously developed tBu-RuPHOX as a chiral ligand. The reaction proceeds via an asymmetric desymmetrization of the meso-diacetatecycloalkenes, providing the desired chiral tetrahydroindoles in moderate to good yields and with up to 96% ee. The annulation reaction could be performed on a gram-scale in high yields and the resulting products can be transformed to several types of N-hetereobicyclic derivatives. In addition, a chiral cis-perhydroindolic acid derivative was also readily synthesized starting from a prepared chiral tetrahydroindole. (Figure presented.).
Nickel-Catalyzed Asymmetric Hydrogenation of N-Sulfonyl Imines
Li, Bowen,Chen, Jianzhong,Zhang, Zhenfeng,Gridnev, Ilya D.,Zhang, Wanbin
supporting information, p. 7329 - 7334 (2019/05/01)
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.
A general method for the preparation of N-sulfonyl aldimines and ketimines
García Ruano, José Luis,Alemán, José,Cid, M. Belén,Parra, Alejandro
, p. 179 - 182 (2007/10/03)
(Chemical Equation Presented) A simple procedure to obtain N-sulfonyl imines involving the condensation of carbonyl compounds with p-tolyl or tert-butyl sulfinamides followed by oxidation with m-CPBA of the resulting N-sulfinylimines is reported. The meth
