Asymmetric Hydrolysis of 1-Cyanoalkyl Acetates

Ohta, H.; Hiraga, Satoshi; Miyamoto, Kenji; Tsuchihashi, Gen-ichi

doi:10.1080/00021369.1988.10869176

Cited by 4 publications

(3 citation statements)

References 5 publications

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“…In the enantioselective hydrogenation of substrate S10 , full conversion required an increase in the catalyst loading, from 1.0 to 2.0 mol%; interestingly, with this substrate, L2 gave a ten percent higher enantiomeric excess than did L1 for the corresponding product (compare entries 18 and 19 in Table 1). To the best of our knowledge, the aforementioned results represent the highest enantioselectivity ever achieved in the synthesis of ( R )‐ O ‐acetyl‐1‐cyanoethanol P10 : the only previously reported route to this compound, based on the enzyme‐mediated enantioselective hydrolysis of racemic 1‐cyanoethyl acetate, gives poor yield and only moderate enantiomeric excess 14. Furthermore, our approach is synthetically advantageous, because the hydrolysis product derived from the previous chiral product [i.e., ( R )‐1‐cyanoethanol] is a valuable chiral synthon for which we found only two enantioselective methods in the literature, both of which give only moderate enantiomeric excesses 15…”

Section: Resultsmentioning

confidence: 82%

Modular POP Ligands in Rhodium‐Mediated Asymmetric Hydrogenation: A Comparative Catalysis Study

et al. 2012

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Highly efficient and enantioselective hydrogenation reactions for a-(acylamino)acrylates, itaconic acid derivatives and analogues, a-substituted enol ester derivatives, and a-arylenamides (25 substrates) catalyzed by chiral cationic rhodium complexes of a set of P À OP ligands have been developed. The catalytic systems derived from these P À OP ligands provided a straightforward access to enantiomerically enriched a-amino acid, carboxylic acid, amine, and alcohol derivatives that are valuable chiral building blocks. Excellent efficiencies (full conversion in all cases) and extremely high enantiomeric excesses (94-99% ee) were achieved for a wide range of a-substituted enol ester derivatives, regardless of the substitution pattern. The R-oxy group of the ligand (methoxy or triphenylmethoxy) strongly influences the enantioselectivity and catalytic activity. Greater steric bulk around the metal centre correlated to greater (or similar) enantioselectivity, but also to slower hydrogenation. Furthermore, the hydrogenation rates observed with the four model substrates follow the same trend, independently of the R-oxy group of the ligand: methyl 2-acetamidoacrylate > dimethyl itaconate > 1-phenylvinyl acetate > N-(1-phenylvinyl)acetamide. A substrate-to-catalyst ratio (S/C) of up to 10,000:1 was sufficient for total hydrogenation of a model substrate of intermediate reactivity (dimethyl itaconate), and did not imply any loss in conversion or enantioselectivity.

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Section: Resultsmentioning

confidence: 82%

Modular POP Ligands in Rhodium‐Mediated Asymmetric Hydrogenation: A Comparative Catalysis Study

et al. 2012

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“…By localizing in a single plasmid the genes encoding the enzymes transketolase and 3-deoxy-~-arabinoheptulosonate synthase, biocatalysis previously exploited in the multi-step, immobilized enzyme synthesis of DAHP ( 107) is reconstructed in an intact microbial cell. In this reaction sequence, fructose-6-phosphate (1 14) is converted into erythrose-4-phosphate (1 15) under the action of transketolase, followed by coupling of (115) with phosphoenol pyruvate (116) in the presence of DAHP synthase to yield DAHP (107). This plasmid biocatalysis takes advantage of the long overlooked impact of transketolase activity on the flow of carbon into aromatic amino acid biosynthesis.…”

Section: Miscellaneous Oxidationsmentioning

confidence: 99%

Recent advances in the use of enzyme-catalysed reactions in organic synthesis

Turner¹

1994

Nat. Prod. Rep.

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“…[37] . ( [25] : 无色液体 0.32 g, 产率 54%, GC 检测＞99% ee, 柱温: 140 ℃, 载气: 1.0 mL/min, t major ＝22.2 min, t minor ＝ [39] .…”

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Direct use of NaCN and aldehydes in one-pot asymmetric synthesis of cyanohydrins by crude (R)-oxynitrilase

Zheng¹,

Yao²,

Li³

et al. 2012

Chin. J. Org. Chem.

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Solid sodium cyanide (NaCN) could be directly used to substitute volatile HCN as cyanide source in the one-pot asymmetric cyanohydrination of aldehydes catalyzed by crude (R)-oxynitrilase from almond with enough acetic acid to restrain the nonenzymatic reaction and racemization of chiral cyanohydrins. The effects of acid, crude (R)-oxynitrilase, volume ratio of water phase, NaCN and reaction temperature on the reaction were investigated. The yields and enantionmeric excess of most of products are higher than 95%. The proposed method has a high application value because of its simplicity, safety, and low cost as well as excellent enantioselectivities and yields.

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Asymmetric Hydrolysis of 1-Cyanoalkyl Acetates

Cited by 4 publications

References 5 publications

Modular POP Ligands in Rhodium‐Mediated Asymmetric Hydrogenation: A Comparative Catalysis Study

Modular POP Ligands in Rhodium‐Mediated Asymmetric Hydrogenation: A Comparative Catalysis Study

Recent advances in the use of enzyme-catalysed reactions in organic synthesis

Direct use of NaCN and aldehydes in one-pot asymmetric synthesis of cyanohydrins by crude (R)-oxynitrilase

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