Enantioselective Reduction of Imines Catalyzed by a Rhenium(V)−Oxo Complex
摘要:
An air- and moisture-tolerant enantioselective hydrosilylation of N-phosphinyl imines employing a chiral Re(V)-oxo complex as a catalyst is described. The chiral catalyst is a cyanobis(oxazoline) (CNbox)-ligated rhenium-oxo complex of the general formula (CNbox)Re(O)Cl2(OPPh3). Using this catalyst, a wide range of aromatic imines (including cyclic, acyclic, and heteroaromatic), alpha-iminoesters, and alpha,beta-unsaturated imines are reduced with good to excellent enantioselectivities.
Synthesis of Air- and Moisture-Stable, Storable Chiral Oxorhenium Complexes and Their Application as Catalysts for the Enantioselective Imine Reduction
salicyloxazoline based oxorhenium(V) complexes have been synthesized and their catalytic application for the asymmetricreduction of ketimines using hydrosilane as hydride source is disclosed. A broad substrate scope, high yields, and excellent enantioselectivities (up to 99 %) are attained. Furthermore, the syntheses of enantiopure α‐amino esters, γ‐ and δ‐lactams, and isoindolinones have also been carried
合成了空气/水分稳定,晶体和可储存的手性水杨基恶唑啉基氧化(V)配合物,并公开了其在氢化硅烷作为氢化物源的情况下催化不对称还原酮亚胺的催化应用。获得了广泛的底物范围,高收率和出色的对映选择性(最高99%)。此外,对映体纯α-氨基酯,γ-和δ-内酰胺以及异吲哚啉酮的合成也已使用该方法进行。最后,该方法已应用于具有药物相关性的合成靶标,例如R -(+)-沙丁胺碱和R -(+)-crispine A.
Asymmetric Transfer Hydrogenation of Ketimines Using Well-Defined Iron(II)-Based Precatalysts Containing a PNNP Ligand
作者:Alexandre A. Mikhailine、Mazharul I. Maishan、Robert H. Morris
DOI:10.1021/ol302079q
日期:2012.9.7
complexes containing PNNP ligands catalyze a highly enantioselective reduction of N-(diphenylphosphinoyl)- and N-(p-tolylsulphonyl)-ketimines. Under mild conditions and low catalyst loading, the ketimines are successfully reduced to the corresponding amines in enantiomeric excess ranging from 94 to 99%.
Enantioselective Hydrosilylation of Imines Catalyzed by Chiral Zinc Acetate Complexes
作者:Agata Bezłada、Marcin Szewczyk、Jacek Mlynarski
DOI:10.1021/acs.joc.5b02613
日期:2016.1.4
A series of zinc acetate complexes with optically pure diphenylethanediamine (DPEDA)-derived ligands have been employed as enantioselectivecatalyst for the hydrosilylation of various imines. High control of stereoselectivity (up to 97% ee) and excellent yields (up to 96%) were gained for a broad range of N-phosphinoylimines by using (R,R)-N,N′-dibenzyl-1,2-diphenylethane-1,2-diamine. This is the first
The present invention relates to a method of enantioselective addition to imines, including: reacting R
3
CH═NY with R
4
ZnR
5
in the presence of a compound represented by the following formula (I),
in which Y, R
1
, R
2
, R
3
, R
4
and R
5
are defined the same as the specification. Accordingly, the present invention can prepare secondary amines in high yields and enantiomeric excess by the above-mentioned method.
Enantioselective Addition of Dialkylzinc to Aromatic Aldimines Mediated by Camphor-Derived Chiral β-Amino Alcohols
作者:Wei-Ming Huang、Biing-Jiun Uang
DOI:10.1002/asia.201403240
日期:2015.4
The enantioselective addition of diethylzinc or dimethylzinc to N‐(diphenylphosphinoyl)imines mediated by 1 or 2 could be achieved in high yields (70–97 %) and enantioselectivities (85–98 % ee). The catalytic loading of 1 or 2 a could be reduced to 10 mol % for methylation or ethylation of imines in high yields and enantioselectivities (79–96 %) when the reaction was conducted in the presence of 1