151073-66-4Relevant articles and documents
Asymmetric Reduction of Aromatic α-Dehydroamino Acid Esters with Water as Hydrogen Source
Dai, Yuze,Chen, Jingchao,Wang, Zheting,Wang, Ting,Wang, Lin,Yang, Yong,Qiao, Xingfang,Fan, Baomin
, p. 7141 - 7147 (2021)
The asymmetric reduction of aromatic α-dehydroamino acid esters with water as the hydrogen source was developed by a Rh/Cu co-catalytic system. The reaction tolerates various functional groups, providing a valuable synthetic tool to access chiral α-amino acid esters readily. Moreover, the present methodology also was applied in the cost-effective and easy to handle preparation of chiral deuterated α-amino esters by using D2O.
Mechanistically Guided One Pot Synthesis of Phosphine-Phosphite and Its Implication in Asymmetric Hydrogenation
Sen, Anirban,Kumar, Rohit,Pandey, Swechchha,Vipin Raj,Kumar, Pawan,Vanka, Kumar,Chikkali, Samir H.
, (2022/01/11)
Although hybrid bidentate ligands are known to yield highly enantioselective products in asymmetric hydrogenation (AH), synthesis of these ligands is an arduous process. Herein, a one pot, atom-economic synthesis of a hybrid phosphine-phosphite (L1) is reported. After understanding the reactivity difference between an O-nucleophile versus C-nucleophile, one pot synthesis of Senphos (L1) was achieved (72 %). When L1 was treated with [Rh], 31P NMR revealed bidentate coordination to Rh. Senphos, in the presence of rhodium, catalyzes the AH of Methyl-2-acetamido-3-phenylacrylate and discloses an unprecedented turn over frequency of 2289, along with excellent enantio-selectivity (92 %). The generality is demonstrated by hydrogenating an array of alkenes. The AH operates under mild conditions of 1–2 bar H2 pressure, at room temperature. The practical relevance of L1 is demonstrated by scaling-up the reaction to 1 g and by synthesizing DOPA, a drug widely employed for the treatment of Parkinson's disease. Computational insights indicate that the R isomer is preferred by 3.8 kcal/mol over the S isomer.
An Atropos Chiral Biphenyl Bisphosphine Ligand Bearing Only 2,2′-Substituents and Its Application in Rh-Catalyzed Asymmetric Hydrogenation
Jia, Jia,Ling, Zheng,Zhang, Zhenfeng,Tamura, Ken,Gridnev, Ilya D.,Imamoto, Tsuneo,Zhang, Wanbin
, p. 738 - 743 (2017/12/26)
An atropos chiral biphenyl bisphosphine ligand bearing only 2,2′-substituents was rationally designed and easily synthesized utilizing a bulky chiral t-butylmethylphosphino block. Computational results showed a large difference in the free energies betwee
