Disulfonimide‐Catalyzed Asymmetric Reduction of
<i>N</i>
‐Alkyl Imines
作者:Vijay N. Wakchaure、Philip S. J. Kaib、Markus Leutzsch、Benjamin List
DOI:10.1002/anie.201504052
日期:2015.9.28
A chiral disulfonimide (DSI)‐catalyzedasymmetric reduction of N‐alkyl imines with Hantzsch esters as a hydrogen source in the presence of Boc2O has been developed. The reaction delivers Boc‐protectedN‐alkyl amines with excellent yields and enantioselectivity. The method tolerates a large variety of alkyl amines, thus illustrating potential for a general reductive cross‐coupling of ketones with diverse
Asymmetric hydrogenation of N-alkyl and N-aryl ketimines using chiral cationic Ru(diamine) complexes as catalysts: the counteranion and solvent effects, and substrate scope
作者:Fei Chen、Ziyuan Ding、Yanmei He、Jie Qin、Tianli Wang、Qing-Hua Fan
DOI:10.1016/j.tet.2012.03.019
日期:2012.7
Asymmetrichydrogenation of N-alkyl and N-aryl ketimines catalyzed by chiralcationic η6-arene-(N-monosulfonylated diamine) Ru(II) complexes has been investigated. Strong counteranion and solvent effects on the enantioselectivity were observed. The ruthenium catalyst bearing non-coordinating BArF− anion was found to be particularly effective for the hydrogenation of acyclic and exocyclic N-alkyl ketimines
Asymmetric Hydrogenation of N-Alkyl Ketimines with Phosphine-Free, Chiral, Cationic Ru-MsDPEN Catalysts
作者:Fei Chen、Tianli Wang、Yanmei He、Ziyuan Ding、Zhiwei Li、Lijin Xu、Qing-Hua Fan
DOI:10.1002/chem.201002846
日期:2011.1.24
(Solvent) free and easy: A phosphine‐free, chiral, cationicRu–MsDPEN complex [(S,S)‐1] is found to be an efficient catalyst for the enantioselective hydrogenation of a range of often‐problematic N‐alkyl ketimines (see scheme). This new method provides a more practical and greener synthetic approach to optically active amines, particularly N‐alkyl amines, such as Sertraline.
Provide that a useful catalyst for homogeneous hydrogenation, particularly a catalyst for homogeneous asymmetric hydrogenation for hydrogenation, particularly asymmetric hydrogenation, which is obtainable with comparative ease and is excellent in economically and workability, and a process for producing a hydrogenated compound of an unsaturated compound, particularly an optically active compound using said catalyst with a high yield and optical purity.
A novel cationic [IrH(THF)(P,N)(imine)] [BArF] catalyst containing a P-stereogenic MaxPHOX ligand is described for the direct asymmetrichydrogenation of N-methyl and N-alkyl imines. This is the first catalytic system to attain high enantioselectivity (up to 94% ee) in this type of transformation. The labile tetrahydrofuran ligand allows for effective activation and reactivity, even at low temperatures