- Enantioselective biomimetic transamination of α-keto acids catalyzed by H4-naphthalene-derived axially chiral biaryl pyridoxamines
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Asymmetric biomimetic transamination is a highly attractive method for synthesis of chemically and biologically important chiral amino acids and chiral amines. Development of chiral pyridoxamines/pyridoxals is the key for the reaction. New axially chiral biaryl pyridoxamines based on H4-naphathene skeleton have been developed. The pyridoxamines display good enantioselectivity and high catalytic activity in asymmetric biomimetic transamination of α-keto acids, affording various optically active unnatural amino acids in 61–98% yields with up to 91% ee's.
- Hou, Chengkang,Zhao, Guoqing,Xu, Dongfang,Zhao, Baoguo
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supporting information
p. 1028 - 1033
(2018/02/15)
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- A new type of chiral-pyridoxamines for catalytic asymmetric transamination of α-keto acids
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A new type of chiral pyridoxamines bearing an adjacent chiral stereocenter has been developed via multi-step synthesis. The pyridoxamines displayed catalytic activity in asymmetric transamination of α-keto acids to give a variety of optically active amino acids in 27–78% yields with 34–62% ee's under very mild conditions. This work provides a synthetic strategy to construct new chiral pyridoxamines using bromopyridine 7 as a key synthon and also represents an early example of the applications of chiral pyridoxamines in asymmetric catalysis.
- Chen, Jianfeng,Zhao, Junyu,Gong, Xing,Xu, Dongfang,Zhao, Baoguo
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supporting information
p. 4612 - 4615
(2016/09/23)
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- Asymmetric Transamination of α-Keto Acids Catalyzed by Chiral Pyridoxamines
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A new type of novel chiral pyridoxamines 3a-g containing a side chain has been developed. The pyridoxamines displayed catalytic activity and promising enantioselectivity in biomimetic asymmetric transamination of α-keto acids, to give various α-amino acids in 47-90% yields with up to 87% ee's under very mild conditions. An interesting effect of the side chain on enantioselectivity was observed in the reaction.
- Lan, Xiaoyu,Tao, Chuangan,Liu, Xuliang,Zhang, Aina,Zhao, Baoguo
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supporting information
p. 3658 - 3661
(2016/08/16)
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- Enzyme-Inspired Axially Chiral Pyridoxamines Armed with a Cooperative Lateral Amine Chain for Enantioselective Biomimetic Transamination
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Enzymatic transamination is catalyzed by pyridoxal/pyridoxamine, and it involves remarkable cooperative catalysis of a Lys residue in the transaminase. Inspired by transaminases, we developed a class of axially chiral pyridoxamines 11 bearing a lateral amine arm. The pyridoxamines exhibited high catalytic activity and excellent enantioselectivity in asymmetric transamination of α-keto acids, to give various α-amino acids in 67-99% yields with 83-94% ee's. The lateral amine arm likely participates in cooperative catalysis as the Lys residue does in biological transamination and has an important impact on the transamination in terms of activity and enantioselectivity.
- Liu, Yong Ethan,Lu, Zhaole,Li, Bo,Tian, Jiaxin,Liu, Feng,Zhao, Junyu,Hou, Chengkang,Li, Yingkun,Niu, Lili,Zhao, Baoguo
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supporting information
p. 10730 - 10733
(2016/09/09)
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- Novel chiral open-chain pyridoxamine catalyst and synthesis method and application thereof
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The invention relates to a novel chiral open-chain pyridoxamine catalyst and a synthesis method and application thereof. The structural general formula of the pyridoxamine catalyst is shown in the specification, wherein R1, R2, R3 and R4 are one of hydrogen, C1-24 alkyl, C1-24 alkyl containing substituent groups, substances shown in the specification and halogen, the substituent groups on C1-24 alkyl are a substance shown in the specification or a substance shown in the specification or a substance shown in the specification or O-Rw or S-Rw' or halogen, and Rx, Rx', Ry, Ry', Ry'', Rz, Rz', Rw and Rw' are one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, tertiary butyl, cyclopentyl, cyclohexyl, cycloheptyl, phenyl, benzyl, (1-phenyl)ethyl, 1-naphthyl, 2-naphthyl and halogen. Compared with the prior art, the pyridoxamine catalyst can achieve rapid and efficient synthesis of chiral amino acid, the preparation raw materials are easy to obtain, reaction conditions are mild, cost is low, and when the novel chiral open-chain pyridoxamine catalyst is used for a transamination reaction, the conditions are mild, and the reaction is stable.
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Paragraph 0175; 0176; 0177; 0178
(2017/01/19)
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- Chiral Pyridoxal-Catalyzed Asymmetric Biomimetic Transamination of α-Keto Acids
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A series of chiral pyridoxals 8 and 9 have been developed from commercially available pyridoxine and (S)-α,α-diarylprolinols. The pyridoxals exhibited good catalytic activity in an asymmetric transamination of α-keto acids with 2,2-diphenylglycine (7f) as the amine source to give various α-amino acids in 29-85% yields with 53-80% ee's. The current asymmetric transamination has successfully mimicked a complete biological transamination process characterized by two half-transaminations, a small chiral pyridoxal molecule acting as the catalyst, and enantioselective control.
- Shi, Limin,Tao, Chuangan,Yang, Qin,Liu, Yong Ethan,Chen, Jing,Chen, Jianfeng,Tian, Jiaxin,Liu, Feng,Li, Bo,Du, Yongling,Zhao, Baoguo
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supporting information
p. 5784 - 5787
(2015/12/11)
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- Synthesis of optically active (2-arylvinyl)glycine derivatives by palladium-catalyzed arylation of (s)-n-(benzyloxycarbonyl)vinylglycine
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Phenyl, tolyl, anisyl, and 1-naphthyl iodides (7a-g,n) smoothly reacted with (S)-N-(benzyloxycarbonyl)-vinylglycine (6) in H2O in the presence of Pd(OAc)2, Bu4NCI, and NaHCO3 at 45°C, producing [S-(E)]-(2- arylvinyl)glycine derivatives 8a-g, n of high enantiomeric purity. The yields of the reactions of 3- (7f), 2- (7e), and 4-iodoanisoles (7g) increased in this order. This relationship between the yield and the position of substitution has been found to hold for bromophenyl iodides (7i-k), although somewhat lower chemical and optical yields were realized in these cases. Phenyl iodide 71 carrying an electron-withdrawing 4-acetyl group gave an unsatisfactory result, and more electron-deficient 4-nitrophenyl iodide (7m) did not provide the desired product. All these results suggest that the reaction is advantageous with electron-sufficient substrates 7. However, this was not the case for 4-iodophenol (7h), as well as some heterocyclic iodides.
- Itaya, Taisuke,Hozumi, Yoshitaka
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p. 1094 - 1101
(2007/10/03)
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