Z -α-乙酰氨基Z酸甲酯(MAC),2-乙酰氨基丙烯酸甲酯(M-丙烯酸酯)和4-甲基-3-乙酰氨基-2-丙酸乙酯(E-EMAP)的三种前手性底物的催化加氢与络合的铑前体据报道,在氢气压力为1–30 bar的情况下,使用手性二膦的化合物。使用了56个手性二膦的文库,包括23个BINAP衍生物,7个JOSIPHOS,5个BIPHEP,3个DUPHOS衍生物和18个其他配体。尽管人们普遍认为,高氢气压力会导致较低的ee s,但现在已在统计基础上证明,对ee的有益和有害压力影响之间的等效分布普遍存在,并且氢压对映性的影响不是孤立的现象,因为所研究的反应体系中有33%以上受到强烈影响。在某些情况下,仅施加较高的氢气压力即可将对映选择性提高至97%。建议将这些结论扩展到其他非手性试剂。
C1-symmetric bisphosphine ligands and their use in the asymmetric synthesis of pregabalin
申请人:Bao Jian
公开号:US20050228190A1
公开(公告)日:2005-10-13
Materials and methods for preparing (S)-(+)-3-(aminomethyl)-5-methyl-hexanoic acid and structurally related compounds via enantioselective hydrogenation of prochiral olefins are disclosed. The methods employ novel chiral catalysts, which include C
1
-symmetric bisphosphine ligands bound to transition metals.
enantioselectivities in methanol as the solvent. This may account for optimised steric and electroniceffects. However, by changing the solvent catalysts with other backbones can give rise to excellent results. This gives proof that simple correlations between steric and electronic properties and results in the enantioselective hydrogenation frequently claimed in literature are not general.
Synthesis of a New Chiral Bisphospholane Ligand for the Rh(I)-Catalyzed Enantioselective Hydrogenation of Isomeric β-Acylamido Acrylates
作者:Jens Holz、Axel Monsees、Haijun Jiao、Jinsong You、Igor V. Komarov、Christine Fischer、Karlheinz Drauz、Armin Börner
DOI:10.1021/jo020453h
日期:2003.3.1
The highly stereoselective synthesis of a chiral silylphospholane has been described, which can be advantageously used as a building block under base-free conditions for the construction of diphosphines related to DuPHOS. The utility of silylphospholane is shown in the synthesis of a new bisphospholane ligand 1 (MalPHOS), which is characterized by a maleic anhydride backbone. The ligand forms with
Highly Enantioselective Asymmetric Hydrogenation of β-Acetamido Dehydroamino Acid Derivatives Using a Three-Hindered Quadrant Rhodium Catalyst
作者:He-Ping Wu、Garrett Hoge
DOI:10.1021/ol048386w
日期:2004.9.1
reported three-hindered quadrant chiral ligand and its corresponding rhodium complex provide high enantioselectivity for the asymmetric hydrogenation of beta-acetamido dehydroaminoacid substrates. Both (E)- and (Z)-substrates are hydrogenated with high enantioselectivity in all of the reported examples. Asymmetric hydrogenation of a cyclic beta-acetamido dehydroaminoacid substrate in 85% ee is also reported
The present invention relates to ligands of the general formula (I).
In addition, a process for the production thereof and the use thereof are demonstrated.