67346-58-1Relevant academic research and scientific papers
Stereoselective Synthesis of 1-Arylpropan-2-amines from Allylbenzenes through a Wacker-Tsuji Oxidation-Biotransamination Sequential Process
González-Martínez, Daniel,Gotor, Vicente,Gotor-Fernández, Vicente
, p. 2582 - 2593 (2019/05/15)
Herein, a sequential and selective chemoenzymatic approach is described involving the metal-catalysed Wacker-Tsuji oxidation of allylbenzenes followed by the amine transaminase-catalysed biotransamination of the resulting 1-arylpropan-2-ones. Thus, a series of nine optically active 1-arylpropan-2-amines were obtained with good to very high conversions (74–92%) and excellent selectivities (>99% enantiomeric excess) in aqueous medium. The Wacker-Tsuji reaction has been exhaustively optimised searching for compatible conditions with the biotransamination experiments, using palladium(II) complexes as catalysts and iron(III) salts as terminal oxidants in aqueous media. The compatibility of palladium/iron systems for the chemical oxidation with commercially available and made in house amine transaminases was analysed, finding ideal conditions for the development of a general and stereoselective cascade sequence. Depending on the selectivity displayed by selected amine transaminase, it was possible to produce both 1-arylpropan-2-amines enantiomers under mild reaction conditions, compounds that present therapeutic properties or can be employed as synthetic intermediates of chiral drugs from the amphetamine family. (Figure presented.).
Amine dehydrogenases: Efficient biocatalysts for the reductive amination of carbonyl compounds
Knaus, Tanja,B?hmer, Wesley,Mutti, Francesco G.
, p. 453 - 463 (2017/08/14)
Amines constitute the major targets for the production of a plethora of chemical compounds that have applications in the pharmaceutical, agrochemical and bulk chemical industries. However, the asymmetric synthesis of α-chiral amines with elevated catalytic efficiency and atom economy is still a very challenging synthetic problem. Here, we investigated the biocatalytic reductive amination of carbonyl compounds employing a rising class of enzymes for amine synthesis: amine dehydrogenases (AmDHs). The three AmDHs from this study-operating in tandem with a formate dehydrogenase from Candida boidinii (Cb-FDH) for the recycling of the nicotinamide coenzyme-performed the efficient amination of a range of diverse aromatic and aliphatic ketones and aldehydes with up to quantitative conversion and elevated turnover numbers (TONs). Moreover, the reductive amination of prochiral ketones proceeded with perfect stereoselectivity, always affording the (R)-configured amines with more than 99% enantiomeric excess. The most suitable amine dehydrogenase, the optimised catalyst loading and the required reaction time were determined for each substrate. The biocatalytic reductive amination with this dual-enzyme system (AmDH-Cb-FDH) possesses elevated atom efficiency as it utilizes the ammonium formate buffer as the source of both nitrogen and reducing equivalents. Inorganic carbonate is the sole by-product.
Stereoselectivity of four (R)-selective transaminases for the asymmetric amination of ketones
Mutti, Francesco G.,Fuchs, Christine S.,Pressnitz, Desiree,Sattler, Johann H.,Kroutil, Wolfgang
experimental part, p. 3227 - 3233 (2012/01/03)
Four (R)-ω-transaminases originating from Hyphomonas neptunium (HN-ωTA), Aspergillus terreus (AT-ωTA) and Arthrobacter sp. (ArR-ωTA), as well as an evolved transaminase (ArRmut11-ωTA) were successfully employed for the amination of prochiral ketones leading to optically pure (R)-amines. The first three transaminases displayed perfect stereoselectivity for the amination of all substrates tested (ee >99%). Furthermore, the transaminase AT-ωTA led in most cases to better conversion than ArR-ωTA and HN-ωTA using D-alanine as amine donor. α-Tetralone, which was the only substrate not accepted by HN-ωTA, ArR-ωTA, and AT-ωTA, was successfully transformed with perfect enantioselectivity (ee >99%) into the corresponding optically pure amine employing the variant ArRmut11-ωTA. Copyright
Efficient synthesis of chiral β-arylisopropylamines by using catalytic asymmetric hydrogenation
Chen, Jian,Zhang, Weicheng,Geng, Huiling,Li, Wei,Hou, Guohua,Lei, Aiwen,Zhang, Xumu
supporting information; experimental part, p. 800 - 802 (2009/05/06)
(Chemical Equation Presented) Direct condensation of β-arylketones with acetamide afforded both Z and E enamides. The Z-configured substrates underwent hydrogenation with excellent enantioselectivity by using the Rh/tang-phos catalytic system (see scheme; tangphos = 1,1′-di-tert-butyl- [2,2′]-diphospholanyl). The product β-arylisopropylamines are important precursors to several drugs.
Formal asymmetric biocatalytic reductive amination
Koszelewski, Dominik,Lavandera, Ivan,Clay, Dorina,Guebitz, Georg M.,Rozzell, David,Kroutil, Wolfgang
supporting information; experimental part, p. 9337 - 9340 (2009/05/15)
All for one: A combination of three biocatalysts (ω-transaminase, alanine dehydrogenase, and an enzyme such as formate dehydrogenase for cofactor recycling) catalyze a cascade to achieve the asymmetric transformation of a ketone into a primary α-chiral unprotected amine through a formal stereoselective reductive amination (see scheme). Only ammonia and the reducing agent (formate) are consumed during this reaction. (Chemical Equation Presented).
