163837-57-8Relevant articles and documents
Asymmetric, catalytic phenyl transfer to imines: Highly enantioselective synthesis of diarylmethylamines
Hermanns, Nina,Dahmen, Stefan,Bolm, Carsten,Braese, Stefan
, p. 3692 - 3694 (2002)
Both planar and central chirality are not necessary in [2.2]paracyclophane-based N,O-ligands to achieve high enantioselectivity: diarylmethylamines are obtained in excellent yields and enantioselectivities up to 97% ee in the enantioselective transfer of a phenyl group from organozinc reagents to imines in the presence of catalytic amounts of ketimine L* (see scheme).
Ruthenium-Catalyzed Direct Asymmetric Reductive Amination of Diaryl and Sterically Hindered Ketones with Ammonium Salts and H2
Hu, Le' an,Zhang, Yao,Zhang, Qing-Wen,Yin, Qin,Zhang, Xumu
supporting information, p. 5321 - 5325 (2020/02/28)
A Ru-catalyzed direct asymmetric reductive amination of ortho-OH-substituted diaryl and sterically hindered ketones with ammonium salts is reported. This method represents a straightforward route toward the synthesis of synthetically useful chiral primary diarylmethylamines and sterically hindered benzylamines (up to 97 % yield, 93–>99 % ee). Elaborations of the chiral amine products into bioactive compounds and a chiral ligand were demonstrated through manipulation of the removable and convertible -OH group.
Isopropylamine as Amine Donor in Transaminase-Catalyzed Reactions: Better Acceptance through Reaction and Enzyme Engineering
Dawood, Ayad W. H.,Wei?, Martin S.,Schulz, Christian,Pavlidis, Ioannis V.,Iding, Hans,de Souza, Rodrigo O. M. A.,Bornscheuer, Uwe T.
, p. 3943 - 3949 (2018/07/31)
Amine transaminases (ATA) have now become frequently used biocatalysts in chemo-enzymatic syntheses including industrial applications. They catalyze the transfer of an amine group from a donor to an acceptor leading to an amine product with high enantiopurity. Hence, they represent an environmentally benign alternative for waste intensive chemical amine synthesis. Isopropylamine (IPA) is probably one of the most favored amine donors since it is cheap and achiral, but nevertheless there is no consistency in literature concerning reaction conditions when IPA is best to be used. At the same time there is still a poor understanding which structural properties in ATA are responsible for IPA acceptance. Herein, we demonstrate, on the basis of the 3FCR enzyme scaffold, a substantial improvement in catalytic activity towards IPA as the amine donor. The asymmetric synthesis of industrial relevant amines was used as model reaction. A systematic investigation of the pH-value as well as concentration effects using common benchmark substrates and several ATA indicates the necessity of a substrate- and ATA-dependent reaction engineering.
Simultaneous engineering of an enzyme's entrance tunnel and active site: The case of monoamine oxidase MAO-N
Li, Guangyue,Yao, Peiyuan,Gong, Rui,Li, Jinlong,Liu, Pi,Lonsdale, Richard,Wu, Qiaqing,Lin, Jianping,Zhu, Dunming,Reetz, Manfred T.
, p. 4093 - 4099 (2017/07/10)
A new directed evolution approach is presented to enhance the activity of an enzyme and to manipulate stereoselectivity by focusing iterative saturation mutagenesis (ISM) simultaneously on residues lining the entrance tunnel and the binding pocket. This combined mutagenesis strategy was applied successfully to the monoamine oxidase from Aspergillus Niger (MAO-N) in the reaction of sterically demanding substrates which are of interest in the synthesis of chiral pharmaceuticals based on the benzo-piperidine scaffold. Reversal of enantioselectivity of Turner-type deracemization was achieved in the synthesis of (S)-1,2,3,4-tetrahydro-1-methyl-isoquinoline, (S)-1,2,3,4-tetrahydro-1-ethylisoquinoline and (S)-1,2,3,4-tetrahydro-1-isopropylisoquinoline. Extensive molecular dynamics simulations indicate that the altered catalytic profile is due to increased hydrophobicity of the entrance tunnel acting in concert with the altered shape of the binding pocket.
