19146-52-2Relevant articles and documents
Chiral Bronsted Acids Catalyze Asymmetric Additions to Substrates that Are Already Protonated: Highly Enantioselective Disulfonimide-Catalyzed Hantzsch Ester Reductions of NH-Imine Hydrochloride Salts
Wakchaure, Vijay N.,Obradors, Carla,List, Benjamin
supporting information, p. 1707 - 1712 (2020/08/28)
While imines are frequently used substrates in asymmetric Bronsted acid catalysis, their corresponding salts are generally considered unsuitable reaction partners. Such processes are challenging because they require the successful competition of a catalytic amount of a chiral anion with a stoichiometric amount of an achiral one. We now show that enantiopure disulfonimides enable the asymmetric reduction of N-H imine hydrochloride salts using Hantzsch esters as hydrogen source. Our scalable reaction delivers crystalline primary amine salts in great efficiency and enantioselectivity and the discovery suggests potential of this approach in other Bronsted acid catalyzed transformations of achiral iminium salts. Kinetic studies and acidity data suggest a bifunctional catalytic activation mode.
Reversal diastereoselectivity between the organomagnesium and organolithium reagents on Chiral N-tert-butylsulfinylaldimines for the preparation of chiral amines
Rajendiran, Chinnapillai,Nagarajan, Periyandi,Naidu,Dubey
, p. 2936 - 2942 (2014/11/08)
The asymmetric synthesis of both the enantiomer of chiral amines from the single chiral source of N-tert-butylsulfinylaldimines (3) by simply changing the organometallic reagents through diastereoselective addition. An efficient enantioselective synthesis of chiral amines including (S)-3-methyl-1-(2- piperidin-1-yl-phenyl)butyl amine (6a), a key intermediate to prepare antidiabetic drug repaglinide (1), is reported.
Enantioselective hydrogenation of N-H imines
Hou, Guohua,Gosselin, Francis,Li, Wei,McWilliams, J. Christopher,Sun, Yongkui,Weisel, Mark,O'Shea, Paul D.,Chen, Cheng-Yi,Davies, Ian W.,Zhang, Xumu
supporting information; experimental part, p. 9882 - 9883 (2009/12/06)
(Figure Presented) N-H ketoimines 3a-3v are readily prepared in high yield via organometallic addition to nitriles and isolated as corresponding bench-stable hydrochloride salts. Homogeneous asymmetric hydrogenation of unprotected N-H ketoimines 3a-3v usi
