Highly Enantioselective Reductive Amination of Simple Aryl Ketones Catalyzed by Ir−f-Binaphane in the Presence of Titanium(IV) Isopropoxide and Iodine
作者:Yongxiang Chi、Yong-Gui Zhou、Xumu Zhang
DOI:10.1021/jo026856z
日期:2003.5.1
Using an Ir-f-Binaphane complex as the catalyst, complete conversions and high enantioselectivies (up to 96% ee) were achieved in the asymmetric reductive amination of aryl ketones in the presence of Ti(O(i)()Pr)(4) and I(2). A simple and efficient method of synthesizing chiral primary amines has been realized.
A series of chiral cyclometalated iridiumcomplexes have been synthesised by cyclometalating chiral 2-aryl-oxazoline and imidazoline ligands with [Cp*IrCl2]2. These iridacycles were studied for asymmetric transfer hydrogenation reactions with formic acid as the hydrogen source and were found to display various activities and enantioselectivities, with the most effective ones affording up to 63% ee
Studies on the Bisoxazoline- and (−)-Sparteine-Mediated Enantioselective Addition of Organolithium Reagents to Imines
作者:Scott E. Denmark、Noriyuki Nakajima、Cory M. Stiff、Olivier J.-C. Nicaise、Michael Kranz
DOI:10.1002/adsc.200800017
日期:2008.5.5
The enantioselective addition of organolithiumreagents to N-anisyl aldimines promoted by chiral bisoxazolines and (-)-sparteine as external ligands is described. This reaction proceeds readily with a wide range of aldimine substrates (aliphatic, aromatic, olefinic) and organolithium nucleophiles (Me, n-Bu, Ph, vinyl) in excellent yields (81-99%) and with high enantioselectivities (up to 95.5:4.5 er)
Synthesis and application of a new pseudo C2-symmetric tertiary diamine for the enantioselective addition of MeLi to aromatic imines
作者:Quentin Perron、Alexandre Alexakis
DOI:10.1016/j.tetasy.2007.10.018
日期:2007.10
A new tertiary pseudo C2-symmetric diamine derived from (1S,2S)-(+)-pseudoephedrine was synthesized and tested in the enantioselective addition of methyllithium on different aromatic imines. A comparative study with a similar C2-symmetric ligand derived from the cyclohexane diamine showed better reactivity and enantioselectivity up to 91%.
Enantioselective addition of organolithium reagents to imines mediated by C2-symmetric bis(aziridine) ligands
作者:Pher G. Andersson、Fredrik Johansson、David Tanner
DOI:10.1016/s0040-4020(98)00675-9
日期:1998.9
The C2-symmetric bis(aziridine) ligands 1–5 have been screened in the enantioselective addition of organolithium reagents to imines. Ligand 1 (used in stoichiometric amounts) was found to be superior in terms of chemical yield and enantioselectivity, the best result being 90% yield and 89% e.e. in the addition of vinyllithium to imine 6a. Use of ligand 1 in substoichiometric amounts gave poorer yield
C 2对称的双(氮丙啶)配体1-5已通过对亚胺类有机锂试剂的对映选择性加成而得到筛选。发现配体1(以化学计量的量使用)在化学产率和对映选择性方面是优异的,最好的结果是在亚胺6a中添加乙烯基锂后,产率为90%,ee为89%。配体1的用途低于化学计量的量给出较差的收率和较低的对映选择性。研究了反应的对映选择性与底物,试剂,化学计量和温度的函数关系,但尚不能得出确切的机械结论。氘标记的甲基锂的初步结果表明涉及配体,试剂和底物的络合/交换过程。