42142-15-4Relevant articles and documents
Direct reductive amination of ketones with ammonium salt catalysed by Cp*Ir(iii) complexes bearing an amidato ligand
Dai, Zengjin,Pan, Ying-Min,Wang, Shou-Guo,Yin, Qin,Zhang, Xumu
supporting information, p. 8934 - 8939 (2021/11/04)
A series of half-sandwich Ir(iii) complexes1-6bearing an amidato bidentate ligand were conveniently synthesized and applied to the catalytic Leuckart-Wallach reaction to produce racemic α-chiral primary amines. With 0.1 mol% of complex1, a broad range of ketones, including aryl ketones, dialkyl ketones, cyclic ketones, α-keto acids, α-keto esters and diketones, could be transformed to their corresponding primary amines with moderate to excellent yields (40%-95%). Asymmetric transformation was also attempted with chiral Ir complexes3-6, and 16% ee of the desired primary amine was obtained. Despite the unsatisfactory enantio-control achieved so far, the current exploration might stimulate more efforts towards the discovery of better chiral catalysts for this challenging but important transformation.
Air Stable Iridium Catalysts for Direct Reductive Amination of Ketones
Polishchuk, Iuliia,Sklyaruk, Jan,Lebedev, Yury,Rueping, Magnus
supporting information, p. 5919 - 5922 (2021/03/08)
Half-sandwich iridium complexes bearing bidentate urea-phosphorus ligands were found to catalyze the direct reductive amination of aromatic and aliphatic ketones under mild conditions at 0.5 mol % loading with high selectivity towards primary amines. One of the complexes was found to be active in both the Leuckart–Wallach (NH4CO2H) type reaction as well as in the hydrogenative (H2/NH4AcO) reductive amination. The protocol with ammonium formate does not require an inert atmosphere, dry solvents, as well as additives and in contrast to previous reports takes place in hexafluoroisopropanol (HFIP) instead of methanol. Applying NH4CO2D or D2 resulted in a high degree of deuterium incorporation into the primary amine α-position.
Method for preparing primary amine by catalyzing reductive amination of aldehyde ketone compounds
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Paragraph 0027-0030; 0080-0084, (2020/05/30)
The invention discloses a method for preparing primary amine by catalyzing reductive amination of aldehyde ketone compounds. The method comprises the following steps: 1) mixing nickel nitrate hexahydrate, citric acid and an organic solvent, carrying out heating and stirring until a colloidal material is obtained, drying the colloidal material, roasting the colloidal material in a protective atmosphere, pickling, washing and drying a roasted product, and performing a partial oxidation reaction on a dried product in an oxygen-nitrogen mixed atmosphere to obtain a catalyst for a reductive amination reaction; and 2) mixing aldehyde or ketone compounds, a methanol solution of ammonia and the reductive amination reaction catalyst, introducing hydrogen, and carrying out a reductive amination reaction. The method has the advantages of high primary amine yield, high selectivity, wide aldehyde ketone substrate range, short reaction time, mild reaction conditions, low cost, greenness, economicalperformance and the like; the used reductive amination reaction catalyst can be recycled more than 10 times, and the catalytic activity of the catalyst is not obviously changed in gram-level reactions; and the method is suitable for large-scale application.
Asymmetric synthesis of primary amines catalyzed by thermotolerant fungal reductive aminases
Cosgrove, Sebastian C.,Grogan, Gideon,Mangas-Sanchez, Juan,Marshall, James R.,Palmer, Ryan B.,Ramsden, Jeremy I.,Sharma, Mahima,Thorpe, Thomas W.,Turner, Nicholas J.
, p. 5052 - 5057 (2020/06/09)
Chiral primary amines are important intermediates in the synthesis of pharmaceutical compounds. Fungal reductive aminases (RedAms) are NADPH-dependent dehydrogenases that catalyse reductive amination of a range of ketones with short-chain primary amines supplied in an equimolar ratio to give corresponding secondary amines. Herein we describe structural and biochemical characterisation as well as synthetic applications of two RedAms fromNeosartoryaspp. (NfRedAm andNfisRedAm) that display a distinctive activity amongst fungal RedAms, namely a superior ability to use ammonia as the amine partner. Using these enzymes, we demonstrate the synthesis of a broad range of primary amines, with conversions up to >97% and excellent enantiomeric excess. Temperature dependent studies showed that these homologues also possess greater thermal stability compared to other enzymes within this family. Their synthetic applicability is further demonstrated by the production of several primary and secondary amines with turnover numbers (TN) up to 14 000 as well as continous flow reactions, obtaining chiral amines such as (R)-2-aminohexane in space time yields up to 8.1 g L?1h?1. The remarkable features ofNfRedAmand NfisRedAm highlight their potential for wider synthetic application as well as expanding the biocatalytic toolbox available for chiral amine synthesis.
Scope and limitations of reductive amination catalyzed by half-sandwich iridium complexes under mild reaction conditions
Nguyen, Dat P.,Sladek, Rudolph N.,Do, Loi H.
supporting information, (2020/07/15)
The conversion of aldehydes and ketones to 1° amines could be promoted by half-sandwich iridium complexes using ammonium formate as both the nitrogen and hydride source. To optimize this method for green chemical synthesis, we tested various carbonyl substrates in common polar solvents at physiological temperature (37 °C) and ambient pressure. We found that in methanol, excellent selectivity for the amine over alcohol/amide products could be achieved for a broad assortment of carbonyl-containing compounds. In aqueous media, selective reduction of carbonyls to 1° amines was achieved in the absence of acids. Unfortunately, at Ir catalyst concentrations of 1 mM in water, reductive amination efficiency dropped significantly, which suggest that this catalytic methodology might be not suitable for aqueous applications where very low catalyst concentration is required (e.g., inside living cells).
Reductive amination of ketonic compounds catalyzed by Cp*Ir(III) complexes bearing a picolinamidato ligand
Tanaka, Kouichi,Miki, Takashi,Murata, Kunihiko,Yamaguchi, Ayumi,Kayaki, Yoshihito,Kuwata, Shigeki,Ikariya, Takao,Watanabe, Masahito
, p. 10962 - 10977 (2019/09/03)
Cp*Ir complexes bearing a 2-picolinamide moiety serve as effective catalysts for the direct reductive amination of ketonic compounds to give primary amines under transfer hydrogenation conditions using ammonium formate as both the nitrogen and hydrogen source. The clean and operationally simple transformation proceeds with a substrate to catalyst molar ratio (S/C) of up to 20,000 at relatively low temperature and exhibits excellent chemoselectivity toward primary amines.
Widely applicable background depletion step enables transaminase evolution through solid-phase screening
Planchestainer, Matteo,Hegarty, Eimear,Heckmann, Christian M.,Gourlay, Louise J.,Paradisi, Francesca
, p. 5952 - 5958 (2019/06/19)
Directed evolution of transaminases is a widespread technique in the development of highly sought-after biocatalysts for industrial applications. This process, however, is challenged by the limited availability of effective high-throughput protocols to evaluate mutant libraries. Here we report a rapid, reliable, and widely applicable background depletion method for solid-phase screening of transaminase variants, which was successfully applied to a transaminase from Halomonas elongata (HEWT), evolved through rounds of random mutagenesis towards a series of diverse prochiral ketones. This approach enabled the identification of transaminase variants in viable cells with significantly improved activity towards para-substituted acetophenones (up to 60-fold), as well as tetrahydrothiophen-3-one and related substrates. Rationalisation of the mutants was assisted by determination of the high-resolution wild-type HEWT crystal structure presented herein.
Evaluation of the Edman degradation product of vancomycin bonded to core-shell particles as a new HPLC chiral stationary phase
Hellinghausen, Garrett,Lopez, Diego A.,Lee, Jauh T.,Wang, Yadi,Weatherly, Choyce A.,Portillo, Abiud E.,Berthod, Alain,Armstrong, Daniel W.
, p. 1067 - 1078 (2018/08/01)
A modified macrocyclic glycopeptide-based chiral stationary phase (CSP), prepared via Edman degradation of vancomycin, was evaluated as a chiral selector for the first time. Its applicability was compared with other macrocyclic glycopeptide-based CSPs: TeicoShell and VancoShell. In addition, another modified macrocyclic glycopeptide-based CSP, NicoShell, was further examined. Initial evaluation was focused on the complementary behavior with these glycopeptides. A screening procedure was used based on previous work for the enantiomeric separation of 50 chiral compounds including amino acids, pesticides, stimulants, and a variety of pharmaceuticals. Fast and efficient chiral separations resulted by using superficially porous (core-shell) particle supports. Overall, the vancomycin Edman degradation product (EDP) resembled TeicoShell with high enantioselectivity for acidic compounds in the polar ionic mode. The simultaneous enantiomeric separation of 5 racemic profens using liquid chromatography-mass spectrometry with EDP was performed in approximately 3?minutes. Other highlights include simultaneous liquid chromatography separations of rac-amphetamine and rac-methamphetamine with VancoShell, rac-pseudoephedrine and rac-ephedrine with NicoShell, and rac-dichlorprop and rac-haloxyfop with TeicoShell.
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.
