63493-28-7Relevant articles and documents
Generation of Oxidoreductases with Dual Alcohol Dehydrogenase and Amine Dehydrogenase Activity
Tseliou, Vasilis,Schilder, Don,Masman, Marcelo F.,Knaus, Tanja,Mutti, Francesco G.
supporting information, p. 3315 - 3325 (2020/12/11)
The l-lysine-?-dehydrogenase (LysEDH) from Geobacillus stearothermophilus naturally catalyzes the oxidative deamination of the ?-amino group of l-lysine. We previously engineered this enzyme to create amine dehydrogenase (AmDH) variants that possess a new hydrophobic cavity in their active site such that aromatic ketones can bind and be converted into α-chiral amines with excellent enantioselectivity. We also recently observed that LysEDH was capable of reducing aromatic aldehydes into primary alcohols. Herein, we harnessed the promiscuous alcohol dehydrogenase (ADH) activity of LysEDH to create new variants that exhibited enhanced catalytic activity for the reduction of substituted benzaldehydes and arylaliphatic aldehydes to primary alcohols. Notably, these novel engineered dehydrogenases also catalyzed the reductive amination of a variety of aldehydes and ketones with excellent enantioselectivity, thus exhibiting a dual AmDH/ADH activity. We envisioned that the catalytic bi-functionality of these enzymes could be applied for the direct conversion of alcohols into amines. As a proof-of-principle, we performed an unprecedented one-pot “hydrogen-borrowing” cascade to convert benzyl alcohol to benzylamine using a single enzyme. Conducting the same biocatalytic cascade in the presence of cofactor recycling enzymes (i.e., NADH-oxidase and formate dehydrogenase) increased the reaction yields. In summary, this work provides the first examples of enzymes showing “alcohol aminase” activity.
Ruthenium Catalyzed Direct Asymmetric Reductive Amination of Simple Aliphatic Ketones Using Ammonium Iodide and Hydrogen
Ernst, Martin,Ghosh, Tamal,Hashmi, A. Stephen K.,Schaub, Thomas
supporting information, (2020/07/14)
The direct conversion of ketones into chiral primary amines is a key transformation in chemistry. Here, we present a ruthenium catalyzed asymmetric reductive amination (ARA) of purely aliphatic ketones with good yields and moderate enantioselectivity: up to 99 percent yield and 74 percent ee. The strategy involves [Ru(PPh3)3H(CO)Cl] in combination with the ligand (S,S)-f-binaphane as the catalyst, NH4I as the amine source and H2 as the reductant. This is a straightforward and user-friendly process to access industrially relevant chiral aliphatic primary amines. Although the enantioselectivity with this approach is only moderate, to the extent of our knowledge, the maximum ee of 74 percent achieved with this system is the highest reported till now apart from enzyme catalysis for the direct transformation of ketones into chiral aliphatic primary amines.
Development of an engineered thermostable amine dehydrogenase for the synthesis of structurally diverse chiral amines
Chen, Fei-Fei,Chen, Qi,Liu, Lei,Wang, Dong-Hao,Wang, Zhi-Long,Xu, Jian-He,Zhang, Zhi-Jun,Zheng, Gao-Wei
, p. 2353 - 2358 (2020/05/13)
Amine dehydrogenases (AmDHs) are emerging as a class of attractive biocatalysts for synthesizing chiral amines via asymmetric reductive amination of ketones with inexpensive ammonia as an amino donor. However, the AmDHs developed to date exhibit limited substrate scope. Here, using directed evolution, we engineered a GkAmDH based on a thermostable phenylalanine dehydrogenase from Geobacillus kaustophilus. The newly developed AmDH is able to catalyze reductive amination of a diverse set of ketones and functionalized hydroxy ketones with ammonia or primary amines with up to >99% conversion, thus accessing structurally diverse chiral primary and secondary amines and chiral vicinal amino alcohols, with excellent enantioselectivity (up to >99% ee) and releasing water as the sole by-product.
