13250-12-9Relevant articles and documents
Preparation of (R)-amines from racemic amines with an (S)-amine transaminase from Bacillus megaterium
Hanson, Ronald L.,Davis, Brian L.,Chen, Yijun,Goldberg, Steven L.,Parker, William L.,Tully, Thomas P.,Montana, Michael A.,Patel, Ramesh N.
, p. 1367 - 1375 (2008)
Screening was carried out to identify strains useful for the preparation of (R)-1-cyclopropylethylamine and (R)-sec-butylamine by resolution of the racemic amines with an (S)-specific transaminase. Several Bacillus megaterium strains from our culture collection as well as several soil isolates were found to have the desired activity for the resolution of the racemic amines to give the (R)-enantiomers. Using an extract of the best strain, Bacillus megaterium SC6394, the reaction was shown to be a trans-amination requiring pyruvate as amino acceptor and pyridoxal phosphate as a cofactor. Initial batches of both amines were produced using whole cells of Bacillus megaterium SC6394. The transaminase was purified to homogeneity to obtain N-terminal as well as internal amino acid sequences. The sequences were used to design polymerase chain reaction (PCR) primers to enable cloning and expression of the trans-aminase in E. coli SC16578. In contrast to the original B. megaterium process, pH control and aeration were not required for the resolution of sec-butyl-amine and an excess of pyruvate was not consumed by the recombinant cells. The resolution of sec-butylamine (0.68M) using whole cells of E. coli SC16578 was scaled up to give (R)-sec-butylamine·1/2 H2SO 4 in 46.6% isolated yield with 99.2% ee. An alternative isolation procedure was also used to isolate (R)-secbutylamine as the free base.
Enzymatic resolution of sec-butylamine
Goswami, Animesh,Guo, Zhiwei,Parker, William L.,Patel, Ramesh N.
, p. 1715 - 1719 (2005)
Resolution of (±)-sec-butylamine by Candida antarctica lipase provided a very low enantiomeric excess of the residual amine when either ethyl or vinyl butyrate was used as the acylating agent. The enantiomeric excess was increased by using ethyl esters of long chain fatty acids. The rate of the reaction was increased by using methyl t-butyl ether as a solvent. (S)-sec-Butylamine of very high enantiomeric excess was obtained by C. antarctica lipase catalyzed acylation with ethyl decanoate in methyl t-butyl ether.
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.
Deracemization of Racemic Amines to Enantiopure (R)- and (S)-amines by Biocatalytic Cascade Employing ω-Transaminase and Amine Dehydrogenase
Yoon, Sanghan,Patil, Mahesh D.,Sarak, Sharad,Jeon, Hyunwoo,Kim, Geon-Hee,Khobragade, Taresh P.,Sung, Sihyong,Yun, Hyungdon
, p. 1898 - 1902 (2019/02/27)
A one-pot deracemization strategy for α-chiral amines is reported involving an enantioselective deamination to the corresponding ketone followed by a stereoselective amination by enantiocomplementary biocatalysts. Notably, this cascade employing a ω-transaminase and amine dehydrogenase enabled the access to both (R)-and (S)-amine products, just by controlling the directions of the reactions catalyzed by them. A wide range of (R)-and (S)-amines was obtained with excellent conversions (>80 %) and enantiomeric excess (>99 % ee). Finally, preparative scale syntheses led to obtain enantiopure (R)- and (S)-13 with the isolated yields of 53 and 75 %, respectively.
