Xi:Irritant;70419-11-3Relevant articles and documents
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.
Reshaping the Active Pocket of Amine Dehydrogenases for Asymmetric Synthesis of Bulky Aliphatic Amines
Chen, Fei-Fei,Zheng, Gao-Wei,Liu, Lei,Li, Hao,Chen, Qi,Li, Fu-Long,Li, Chun-Xiu,Xu, Jian-He
, p. 2622 - 2628 (2018/03/13)
The asymmetric reductive amination of ketones with ammonia using engineered amine dehydrogenases (AmDHs) is a particularly attractive and environmentally friendly method for the synthesis of chiral amines. However, one major challenge for these engineered AmDHs is their limited range of accepted substrates. Herein, several engineered AmDHs were developed through the evolution of naturally occurring leucine dehydrogenases, which displayed good amination activity toward aliphatic ketones but restricted catalytic scope for short-chain substrates. Computational analysis helped identify two residues, located at the distal end of the substrate-binding cavity, that generate steric hindrance and prevent the binding of bulky aliphatic ketones. By fine-tuning these two key hotspots, the resulting AmDH mutants are able to accept previously inaccessible bulky substrates. More importantly, the mutations were also proved applicable for expanding the substrate scope of other homologous AmDHs with sequence identities as low as 70%, indicating a broad effect on the development of AmDHs and the synthesis of structurally diverse chiral amines.
N-octanoyldimethylglycine trifluoroethyl ester, an acyl donor leading to highly enantioselective protease-catalysed kinetic resolution of amines
Queyroy, Severine,Vanthuyne, Nicolas,Gastaldi, Stephane,Bertrand, Michele P.,Gil, Gerard
supporting information; experimental part, p. 1759 - 1764 (2012/08/08)
The use of N-octanoyldimethylglycine trifluoroethyl ester as acyl donor in the kinetic resolution of aliphatic amines catalysed by proteases led to enantiomeric ratios >200 in most cases. The resolutions mediated by Protex 6L were shown to be much faster
