- Scope and limitations of reductive amination catalyzed by half-sandwich iridium complexes under mild reaction conditions
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The conversion of aldehydes and ketones to 1° amines could be promoted by half-sandwich iridium complexes using ammonium formate as both the nitrogen and hydride source. To optimize this method for green chemical synthesis, we tested various carbonyl substrates in common polar solvents at physiological temperature (37 °C) and ambient pressure. We found that in methanol, excellent selectivity for the amine over alcohol/amide products could be achieved for a broad assortment of carbonyl-containing compounds. In aqueous media, selective reduction of carbonyls to 1° amines was achieved in the absence of acids. Unfortunately, at Ir catalyst concentrations of 1 mM in water, reductive amination efficiency dropped significantly, which suggest that this catalytic methodology might be not suitable for aqueous applications where very low catalyst concentration is required (e.g., inside living cells).
- Nguyen, Dat P.,Sladek, Rudolph N.,Do, Loi H.
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supporting information
(2020/07/15)
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- Glutamate as an Efficient Amine Donor for the Synthesis of Chiral β- and γ-Amino Acids Using Transaminase
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A recyclable glutamate amine donor system employing transaminase (TA), glutamate dehydrogenase (GluDH) and mutant formate dehydrogenase (FDHm) was developed, wherein amine donor Glu was regenerated using GluDH and thereby circumvented the inhibition of TA by α-ketoglutarate. Various enantiopure β-, γ-amino acids, and amines were successfully synthesized with high conversions and excellent enantiomeric excess using this system.
- Kim, Geon-Hee,Jeon, Hyunwoo,Khobragade, Taresh P.,Patil, Mahesh D.,Sung, Sihyong,Yoon, Sanghan,Won, Yumi,Sarak, Sharad,Yun, Hyungdon
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p. 1437 - 1440
(2019/02/06)
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- Enzymatic synthesis of chiral γ-amino acids using ω-transaminase
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In this study, we successfully synthesized enantiomerically pure (R)- and (S)-γ-amino acids (>99% ee) using ω-transaminase (ω-TA) through kinetic resolution and asymmetric synthesis respectively. The present study demonstrates the high potentiality of ω-TA reaction for the production of chiral γ-amino acids.
- Shon, Minsu,Shanmugavel, Ramachandran,Shin, Giyoung,Mathew, Sam,Lee, Sang-Hyeup,Yun, Hyungdon
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p. 12680 - 12683
(2015/05/20)
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- Phenyl-Substituted Analogues of Oxotremorine as Muscarinic Antagonists
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A series of phenyl-substituted analogues of the muscarinic agent oxotremorine (1) have been prepared.The new compounds (3b-11b and 9c) were assayed for antimuscarinic activity on the isolated guinea pig ileum and in intact mice.They were also evaluated for ability to inhibit the binding of the muscarinic antagonist (-)--N-methylscopolamine to homogenates of the rat cerebral cortex.The phenyl-substituted derivatives were devoid of intrinsic muscarinic activity.Instead, they behaved as competitive muscarinic antagonists in these assays with similar or lower affinity for muscarinic receptors than the corresponding methyl-substituted analogues.The succinimide (8b) and the pyrrolidone (3b) derivatives of 1 substituted with a phenyl group at position 1 of the bytynyl chain showed the highest antimuscarinic potency with dissociation constants (KD) of 0.10 and 0.20 μM, respectively, in the ileum assay.The phenyl-substituted analogues showed an approximately 10-fold lower in vivo antimuscarinic potency than their corresponding methyl-substituted position isomers.A correlation was observed between in vitro and in vivo potency within subsets consisting of methyl- and phenyl-substituted derivatives.
- Nilsson, Bjoern M.,Vargas, Hugo M.,Ringdahl, Bjoern,Hacksell, Uli
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p. 285 - 294
(2007/10/02)
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