3082-68-6Relevant articles and documents
Highly enantioselective one-pot, three-component imino-reformatsky reaction
Cozzi, Pier Giorgio,Rivalta, Eleonora
, p. 3600 - 3603 (2005)
(Chemical Equation Presented) A key to molecular diversity is the preparation of new frameworks in multi-component condensations of three or more reactants. A new highly enantioselective one-pot, three-component, nickel-catalyzed, imino-Reformatsky reacti
Enantioselective synthesis of amines via reductive amination with a dehydrogenase mutant from Exigobacterium sibiricum: Substrate scope, co-solvent tolerance and biocatalyst immobilization
L?we, Jana,Ingram, Aaron A.,Gr?ger, Harald
, p. 1387 - 1392 (2018/03/21)
In recent years, the reductive amination of ketones in the presence of amine dehydrogenases emerged as an attractive synthetic strategy for the enantioselective preparation of amines starting from ketones, an ammonia source, a reducing reagent and a cofactor, which is recycled in situ by means of a second enzyme. Current challenges in this field consists of providing a broad synthetic platform as well as process development including enzyme immobilization. In this contribution these issues are addressed. Utilizing the amine dehydrogenase EsLeuDH-DM as a mutant of the leucine dehydrogenase from Exigobacterium sibiricum, a range of aryl-substituted ketones were tested as substrates revealing a broad substrate tolerance. Kinetics as well as inhibition effects were also studied and the suitability of this method for synthetic purpose was demonstrated with acetophenone as a model substrate. Even at an elevated substrate concentration of 50 mM, excellent conversion was achieved. In addition, the impact of water-miscible co-solvents was examined, and good activities were found when using DMSO of up to 30% (v/v). Furthermore, a successful immobilization of the EsLeuDH-DM was demonstrated utilizing a hydrophobic support and a support for covalent binding, respectively, as a carrier.
Chiral Lewis Base-Catalyzed, Enantioselective Reduction of Unprotected β-Enamino Esters with Trichlorosilane
Ye, Jianheng,Wang, Chao,Chen, Lin,Wu, Xinjun,Zhou, Li,Sun, Jian
supporting information, p. 1042 - 1047 (2016/04/19)
Catalytic asymmetric reduction of N-unsubstituted β-enamino esters represents a major challenge for asymmetric catalysis. In this paper, the first organocatalytic system that could be used for the asymmetric hydrosilylation of N-unsubstituted β-enamino esters has been developed. Using N-tert-butylsulfinyl-L-proline-derived amides and L-pipecolinic acid-derived formamides as catalyst, a broad range of β-aryl- and β-alkyl-substituted free β-amino esters could be prepared with high yields and enantioselectivities. The practicality was illustrated by the gram-scale asymmetric synthesis of ethyl (R)-3-amino-3-phenylpropanoate and isopropyl (S)-3-amino-4-(2,3,5-trifluorophenyl)butanoate. The resulting product can be smoothly transformed to the FDA approved medicines dapoxetine and sitagliptin in a short synthetic route.
Asymmetric synthesis of 2-substituted cyclic amines
Kudale, Amit A.,Anaspure, Prasad,Goswami, Falguni,Voss, Matthew
, p. 7219 - 7221 (2015/01/09)
Cyanomethylenetributylphosphorane-mediated ring closure for the asymmetric synthesis of 2-substituted cyclic amines such as azetidines, pyrrolidines and a piperidine is reported. The desired stereochemistry at the 2-position was fixed using (S)-tert-butyl sulfinamide as a chiral auxiliary.
