23601-98-1Relevant academic research and scientific papers
Generation of amine dehydrogenases with increased catalytic performance and substrate scope from ε-deaminating L-Lysine dehydrogenase
Tseliou, Vasilis,Knaus, Tanja,Masman, Marcelo F.,Corrado, Maria L.,Mutti, Francesco G.
, (2019/08/22)
Amine dehydrogenases (AmDHs) catalyse the conversion of ketones into enantiomerically pure amines at the sole expense of ammonia and hydride source. Guided by structural information from computational models, we create AmDHs that can convert pharmaceutically relevant aromatic ketones with conversions up to quantitative and perfect chemical and optical purities. These AmDHs are created from an unconventional enzyme scaffold that apparently does not operate any asymmetric transformation in its natural reaction. Additionally, the best variant (LE-AmDH-v1) displays a unique substrate-dependent switch of enantioselectivity, affording S- or R-configured amine products with up to >99.9% enantiomeric excess. These findings are explained by in silico studies. LE-AmDH-v1 is highly thermostable (Tm of 69 °C), retains almost entirely its catalytic activity upon incubation up to 50 °C for several days, and operates preferentially at 50 °C and pH 9.0. This study also demonstrates that product inhibition can be a critical factor in AmDH-catalysed reductive amination.
An Ammonium-Formate-Driven Trienzymatic Cascade for ω-Transaminase-Catalyzed (R)-Selective Amination
Chen, Fei-Fei,Liu, Lei,Wu, Jian-Ping,Xu, Jian-He,Zhang, Yu-Hui,Zhang, Zhi-Jun,Zheng, Gao-Wei
, p. 14987 - 14993 (2019/12/02)
(R)-Amination mediated by (R)-specific ω-transaminases generally requires costly d-alanine in excess to obtain the desired chiral amines in high yield. Herein, a one-pot, trienzymatic cascade comprising an (R)-specific ω-transaminase, an amine dehydrogenase, and a formate dehydrogenase was developed for the economical and eco-friendly synthesis of (R)-chiral amines. Using inexpensive ammonium formate as the sole sacrificial agent, the established cascade system enabled efficient ω-transaminase-mediated (R)-amination of various ketones, with high conversions and excellent ee (>99%); water and CO2 were the only waste products.
Green synthesis of benzamides in solvent- and activation-free conditions
Alalla, Affef,Merabet-Khelassi, Mounia,Aribi-Zouioueche, Louisa,Riant, Olivier
supporting information, p. 2364 - 2376 (2014/07/22)
Herein, we describe a clean and ecocompatible pathway for both N-benzoylation and N-acetylation of anilines, amines, diamines, and aminoalcohols using three enol esters with good yields. We have improved the use of vinyl benzoate for the direct introduction of a benzamido-moiety under solvent- and activation-free conditions. The recovered amides are easily isolated by crystallization. Copyright
The Effect of Electrochemically Generated Positive Bromine Species in Acetonitrile on the Cleavage of C-Br and C-Cl Bonds.
Becker, James Y.,Zemach, Dvora
, p. 336 - 340 (2007/10/02)
The fate of bromine formed from C-Br cleavage during the course of anodic oxidation of alkyl bromides in acetonitrile on platinum has been investigated potentiostatically.It is suggested that positive bromine species are formed and they are potentially reactive towards alkyl bromides, yielding similar products to those obtained by direct anodic oxidation of the same bromides.Furthermore, whereas alkyl chlorides do not undergo C-Cl fission by direct anodic oxidation it is shown that positive bromine species are energetically sufficient to break C-Cl bonds, although not very efficiently.We suggest that a possible structure for the complex between acetonitrile and positive bromine species is mainly +Br3- and the mechanism for its formation is discussed.The spectrum of this species found identical to that of Br3- (269 nm) in acetonitrile.
Nitrogen-15 Nuclear Magnetic Rasonance Spectroscopy. Natural Abundance Nitrogen-15 Spectra of the cis and trans Isomers of Secondary Alkylformamides
Nakanishi, Hiroshi,Roberts, John D.
, p. 7 - 12 (2007/10/02)
The 15N NMR chemical shifts were measured of a number of N-substituted formamides and acetamides at the natural abundance level.The ratios of the cis and trans isomers for several N-alkylformamides were also determined.Substituent effects on the 15N chemical shifts of formamides are compared with those of some other nitrogen-containing compounds.There is a consistent pattern of behavior of the one bond spin-spin coupling constants 1J(15NH)> wherein the trans isomers of N-alkylformamides are larger than those of the cis isomers.
