23943-56-8Relevant academic research and scientific papers
Copper(I)-catalyzed asymmetric hydrosilylations of imines at ambient temperatures
Lipshutz, Bruce H.,Shimizu, Hideo
, p. 2228 - 2230 (2004)
Are you looking for an operationally simple means of preparing enantio-enriched benzylic-like centers bearing nitrogen? Consider this new and convenient alternative to asymmetric hydrogenation: CuH when ligated by an enantio-pure SEGPHOS ligand can cataly
Microwave-accelerated enantioselective addition of dialkylzinc reagents to N-(diphenylphosphinoyl)imines catalysed by β-aminoalcohols with the prolinol skeleton
Almansa, Raquel,Guijarro, David,Yus, Miguel
, p. 1376 - 1380 (2008)
The addition of dialkylzinc reagents to N-(diphenylphosphinoyl)imines in the presence of a catalytic amount of a β-aminoalcohol with the prolinol framework under microwave irradiation gives the expected addition products in good yields and with an ee of u
Asymmetric reduction method of nitrogen-phosphonyl protected imine
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Paragraph 0073-0078, (2021/01/15)
The invention discloses an asymmetric reduction method of nitrogen phosphonyl protective imine. The nitrogen phosphonyl protective imine is reduced into chiral amine in a hydrogen atmosphere under theaction of a metal catalyst and alkali, and the metal catalyst is prepared from a metal iridium complex and a nitrogen-phosphorus chiral ligand. The method provided by the invention has the characteristics of high enantioselectivity, high yield and high conversion number (TON). The method can be used for synthesizing various substituted chiral amines, can be used as an important intermediate for preparing various medicines, and has important significance for industrial production of medicines.
Asymmetric Transfer Hydrogenation in Thermomorphic Microemulsions Based on Ionic Liquids
Hejazifar, Mahtab,Pálv?lgyi, ádám Márk,Bitai, Jacqueline,Lanaridi, Olga,Bica-Schr?der, Katharina
, p. 1841 - 1851 (2019/10/11)
A thermomorphic ionic-liquid-based microemulsion system was successfully applied for the Ru-catalyzed asymmetric transfer hydrogenation of ketones. On the basis of the temperature-dependent multiphase behavior of the targeted microemulsion, simple product separation as well as catalyst recycling could be realized. The use of water-soluble ligands improved the immobilization of the catalyst in the microemulsion phase and significantly decreased the catalyst leaching into the organic layer upon extraction of the product. Eventually, the optimized microemulsion system could be applied to a wide range of aromatic ketones that were reduced with good isolated yields (up to 98%) and enantioselectivities (up to 97%), while aliphatic ketones were less successful.
Asymmetric Stepwise Reductive Amination of Sulfonamides, Sulfamates, and a Phosphinamide by Nickel Catalysis
Zhao, Xiaohu,Xu, Haiyan,Huang, Xiaolei,Zhou, Jianrong Steve
supporting information, p. 292 - 296 (2018/12/13)
Asymmetric reductive amination of poorly nucleophilic sulfonamides was realized in the presence of nickel catalysts and titanium alkoxide. A wide range of ketones, including enolizable ketones and some biaryl ones, were converted into sulfonamides in excellent enantiomeric excess. The cyclization of sulfamates and intermolecular reductive amination of a diarylphosphinamide were also successful. Formic acid was used as a safe and economic surrogate of high-pressure hydrogen gas.
A New Phosphine-Amine-Oxazoline Ligand for Ru-Catalyzed Asymmetric Hydrogenation of N-Phosphinylimines
Ma, Xiaochen,Qiao, Lin,Liu, Guixia,Huang, Zheng
supporting information, p. 1151 - 1155 (2018/10/15)
A series of chiral phosphine-amine-oxazoline (PAO) ligands with an NH moiety were synthesized and applied to the ruthenium-catalyzed asymmetric hydrogenation of N-phosphinylimines. The ligand bearing phenyl groups at the phosphorus moiety and isopropyl at the oxazoline moiety exhibits good activity and excellent enantioselectivity (up to 99% ee). This catalytic system provides an efficient and mild approach to access enantioriched amines.
Highly Enantioselective Transfer Hydrogenation of Polar Double Bonds by Macrocyclic Iron(II)/(NH)2P2 Catalysts
Bigler, Raphael,Mezzetti, Antonio
supporting information, p. 253 - 261 (2016/03/04)
We describe herein a new protocol for the synthesis of 2,2′-((1S,1′S)-ethane-1,2-diylbis(phenylphosphanediyl))dibenzaldehyde ((SP,SP)-5), which is the key intermediate in the synthesis of macrocyclic iron(II)/(NH)2P2 catalysts for the highly enantioselective transfer hydrogenation of polar double bonds. The dialdehyde (SP,SP)-5 was obtained as a single diastereoisomer and enantiomer from an optically pure H-phosphinate in 33% yield over five steps. It was further converted to afford multigram quantities of the macrocyclic iron(II)/(NH)2P2 complexes, which were tested in the asymmetric transfer hydrogenation of aryl alkyl ketones and imines in 2-propanol on a 100 mmol scale. Ten substrates, including challenging ones such as tert-butyl phenyl ketone and industrially relevant molecules such as 3,5-bis(trifluoromethyl)acetophenone, were reduced in high yield (89.0-99.7%), excellent enantioselectivity (95.8-99.4% ee), and with low catalyst loadings (S/C up to 10 000/1).
Iron(II)/(NH)2P2 Macrocycles: Modular, Highly Enantioselective Transfer Hydrogenation Catalysts
Bigler, Raphael,Huber, Raffael,St?ckli, Marco,Mezzetti, Antonio
, p. 6455 - 6464 (2016/10/18)
A generalized protocol for the synthesis of chiral (NH)2P2 macrocycles allows changing the linker between the phosphines and gives access to a family of such ligands, as demonstrated for the propane-1,3-diyl analogue. The corresponding complexes based on earth-abundant and nontoxic iron were applied as catalysts in the asymmetric transfer hydrogenation of polar double bonds. Thanks to the ligand modularity and to the use of tunable isonitriles as ancillary ligands, the catalyst system can be individually optimized for each substrate to give high enantioselectivity (up to 99.9% conversion and 99.6% ee, TOF up to >3950 h-1) for a broad scope of 26 substrates.
Enantioselective Hydrosilylation of Imines Catalyzed by Chiral Zinc Acetate Complexes
Bez?ada, Agata,Szewczyk, Marcin,Mlynarski, Jacek
, p. 336 - 342 (2016/01/15)
A series of zinc acetate complexes with optically pure diphenylethanediamine (DPEDA)-derived ligands have been employed as enantioselective catalyst 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 successful application of an air-stable and environmentally friendly chiral Zn(OAc)2 complex instead of the previously used harmful diethylzinc in the asymmetric reduction of the C=N double bond.
Enantioselective addition of dialkylzinc to aromatic aldimines mediated by camphor-derived chiral β-amino alcohols
Huang, Wei-Ming,Uang, Biing-Jiun
supporting information, p. 998 - 1003 (2015/03/31)
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 2a could be reduced to 10 mol% f
