162427-79-4Relevant articles and documents
Iron(II) Complexes Containing Chiral Unsymmetrical PNP′ Pincer Ligands: Synthesis and Application in Asymmetric Hydrogenations
Zirakzadeh, Afrooz,Kirchner, Karl,Roller, Alexander,St?ger, Berthold,Widhalm, Michael,Morris, Robert H.
, p. 3781 - 3787 (2016)
Four new chiral PNP′ pincer ligands with a scaffold consisting of a planar chiral ferrocene and a centro chiral aliphatic unit were synthesized and characterized. Treatment of anhydrous FeBr2(THF)2 with 1 equiv of the unsymmetrical chiral PNP′ pincer ligands afforded complexes of the general formula [Fe(PNP′)Br2]. In the solid state these complexes adopt a tetrahedral geometry with the PNP′ ligands coordinated in a ?°2P,N-fashion, as shown by X-ray crystallography. These complexes react with CO in the presence of NaBH4 to yield hydride complexes of the type [Fe(PNP′)(H)(Br)(CO)], which were isolated and tested as catalysts in the asymmetric hydrogenation of ketones. Enantioselectivities of up to 81% ee were obtained.
The enantioselective reduction of 2′-fluoroacetophenone utilizing a simplified CBS-reduction procedure
Garrett, Christine E,Prasad, Kapa,Repic, Oljan,Blacklock, Thomas J.
, p. 1347 - 1349 (2002)
We have developed a practical, non-enzymatic, catalytic process for the enantioselective reduction of 2′-fluoroacetophenone. A number of catalysts were screened for the oxazaborolidine-type reduction of this ketone to obtain an optimized system. We have s
Tridentate nitrogen phosphine ligand containing arylamine NH as well as preparation method and application thereof
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Paragraph 0095-0102; 0105-0109, (2021/06/26)
The invention discloses a tridentate nitrogen phosphine ligand containing arylamine NH as well as a preparation method and application thereof, and belongs to the technical field of organic synthesis. The tridentate nitrogen phosphine ligand disclosed by the invention is the first case of tridentate nitrogen phosphine ligand containing not only a quinoline amine structure but also chiral ferrocene at present, a noble metal complex of the type of ligand shows good selectivity and extremely high catalytic activity in an asymmetric hydrogenation reaction, meanwhile, a cheap metal complex of the ligand can also show good selectivity and catalytic activity in the asymmetric hydrogenation reaction, and is very easy to modify in the aspects of electronic effect and space structure, so that the ligand has huge potential application value. A catalyst formed by the ligand and a transition metal complex can be used for catalyzing various reactions, can be used for synthesizing various drugs, and has important industrial application value.
C1-Symmetric PNP Ligands for Manganese-Catalyzed Enantioselective Hydrogenation of Ketones: Reaction Scope and Enantioinduction Model
Zeng, Liyao,Yang, Huaxin,Zhao, Menglong,Wen, Jialin,Tucker, James H. R.,Zhang, Xumu
, p. 13794 - 13799 (2020/11/30)
A family of ferrocene-based chiral PNP ligands is reported. These tridentate ligands were successfully applied in Mn-catalyzed asymmetric hydrogenation of ketones, giving high enantioselectivities (92%~99% ee for aryl alkyl ketones) as well as high efficiencies (TON up to 2000). In addition, dialkyl ketones could also be hydrogenated smoothly. Manganese intermediates that might be involved in the catalytic cycle were analyzed. DFT calculation was carried out to help understand the chiral induction model. The Mn/PNP catalyst could discriminate two groups with different steric properties by deformation of the phosphine moiety in the flexible 5-membered ring.