- Synthesis of Unprotected 2-Arylglycines by Transamination of Arylglyoxylic Acids with 2-(2-Chlorophenyl)glycine
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The transamination of α-keto acids with 2-phenylglycine is an effective methodology for directly synthesizing unprotected α-amino acids. However, the synthesis of 2-arylglycines by transamination is problematic because the corresponding products, 2-arylglycines, transaminate the starting arylglyoxylic acids. Herein, we demonstrate the use of commercially available l-2-(2-chlorophenyl)glycine as the nitrogen source in the transamination of arylglyoxylic acids, producing the corresponding 2-arylglycines without interference from the undesired self-transamination process.
- Inada, Haruki,Shibuya, Masatoshi,Yamamoto, Yoshihiko
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p. 11047 - 11059
(2020/10/12)
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- One-Pot Enantioselective Synthesis of d-Phenylglycines from Racemic Mandelic Acids, Styrenes, or Biobased l-Phenylalanine via Cascade Biocatalysis
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Enantiopure d-phenylglycine and its derivatives are an important group of chiral amino acids with broad applications in thepharmaceutical industry. However, the existing synthetic methods for d-phenylglycine mainly rely on toxic cyanide chemistry and multistep processes. To provide green and safe alternatives, we envisaged cascade biocatalysis for the one-pot synthesis of d-phenylglycine from racemic mandelic acid, styrene, and biobased l-phenylalanine, respectively. Recombinant Escherichia coli (LZ110) was engineered to coexpress four enzymes to catalyze a 3-step reaction in one pot, transforming mandelic acid (210 mM) to give enantiopure d-phenylglycine in 29.5 g L?1 (195 mM) with 93% conversion. Using the same whole-cell catalyst, twelve other d-phenylglycine derivatives were also produced from the corresponding mandelic acid derivatives in high conversion (58–94%) and very high ee (93–99%). E. coli (LZ116) expressing seven enzymes was constructed for the transformation of styrene to enantiopure d-phenylglycine in 80% conversion via a one-pot 6-step cascade biotransformation. Twelve substituted d-phenylglycines were also produced from the corresponding styrene derivatives in high conversion (45–90%) and very high ee (92–99%) via the same cascade reactions. A nine-enzymeexpressing E. coli (LZ143) was engineered to transform biobased l-phenylalanine to enantiopure d-phenylglycine in 83% conversion via a one-pot 8-step transformation. Preparative biotransformations were also demonstrated. The high-yielding synthetic methods use cheap and green reagents (ammonia, glucose, and/or oxygen), and E. coli whole-cell catalysts, thus providing green and useful alternative methods for manufacturing d-phenylglycine. (Figure presented.).
- Zhou, Yi,Wu, Shuke,Li, Zhi
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supporting information
p. 4305 - 4316
(2017/11/21)
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- Preparation method for D, L-phenylglycine and analogue thereof
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The invention provides a preparation method for D, L-phenylglycine and an analogue thereof. According to the method, benzaldehyde, an analogue thereof and hydrocyanic acid are adopted as raw materials and subjected to cyanidation reaction, and then 2-hydroxy-benzyl cyanide or 2-hydroxy-benzyl cyanide analogue (cyanohydrin for short) is generated. Cyanohydrin reacts with carbon dioxide and the aqueous solution of ammonia, and then 5-phenyl-hydantoin and an analogue thereof (hydantoin for short) are generated. hydantoin is successively subjected to steam stripping, alkaline hydrolysis, steam stripping, decolorization, neutralization, crystallization, washing, centrifuging, drying and the like to obtain D, L-phenylglycine and the analogue thereof. Compared with the prior art, the preparation method for D, L-phenylglycine and the analogue thereof can significantly and effectively reduce the pollution, and fewer inorganic salt by-products are generated. Meanwhile, the prepared D, L-phenylglycine and the analogue thereof are high in product yield and high in purity. Counted in benzaldehyde and the analogue thereof, the yield of D, L-phenylglycine and the analogue thereof is larger than or equal to 96%, and the product purity is larger than or equal to 99%. Meanwhile, the process flow is simple and feasible, so that the method is worthy of market popularization and application.
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Paragraph 0045; 0046
(2017/03/17)
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- Efficient access to (1H)-isoindolin-1-one-3-carboxylic acid derivatives by orthopalladation and carbonylation of methyl arylglycinate substrates
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The orthopalladation of methyl arylglycinate derivatives has been studied. The reaction proceeds efficiently for different electron-withdrawing and electron-releasing substituents at the aryl ring. The carbonylation of the orthopalladated complexes affords, in a single step, substituted (1H)-isoindolin-1-one-3-carboxylates. These compounds constitute valuable synthetic intermediates and can be transformed diastereoselectively into octahydroisoindole-1-carboxylic acid derivatives, an important scaffold in the synthesis of many biologically active compounds.
- Nieto, Sonia,Sayago, Francisco J.,Laborda, Pedro,Soler, Tatiana,Cativiela, Carlos,Urriolabeitia, Esteban P.
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experimental part
p. 4185 - 4191
(2011/07/08)
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- Chemistry of unprotected amino acids in aqueous solution: Direct bromination of aromatic amino acids with bromoisocyanuric acid sodium salt under strong acidic condition
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Brominations of unprotected aromatic amino acids such as phenylalanine, tyrosine, and glycine, with bromoisocyanuric acid mono sodium salt (BICA-Na) were conducted in 60% aq. H2SO4 at 0°C to give a mixture of mono-brominated products in good yield. Unexpectedly, meta-bromophenylglycine was obtained as main product accompanied by ortho- and para-substituted products, while phenylalanine gave only ortho- and para-substituted products. Bromination of 2-phenylethylamine or benzylamine showed a tendency similar to the corresponding amino acids.
- Yokoyama, Yuusaku,Yamaguchi, Tomotsugu,Sato, Masanori,Kobayashi, Eri,Murakami, Yasuoki,Okuno, Hiroaki
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p. 1715 - 1719
(2007/10/03)
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- ASYMMETRIC INDUCTIVE SYNTHESIS OF α-AMINOARYLACETIC ACIDS IN CHIRAL MICELLAR SYSTEM
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In the micellar solution of chiral surfactant N-hexadecyl-N-methylephedrine bromide, seven α-aminoarylacetic acids were synthesized from corresponding aldehydes, the e.e.percent being about 28percent.
- Zhang, Yongmin,Li, Weixing
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p. 1685 - 1690
(2007/10/02)
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