4263-93-8Relevant articles and documents
One-pot, two-step synthesis of unnatural α-amino acids involving the exhaustive aerobic oxidation of 1,2-diols
Inada, Haruki,Furukawa, Keisuke,Shibuya, Masatoshi,Yamamoto, Yoshihiko
supporting information, p. 15105 - 15108 (2019/12/26)
Herein, we report the nor-AZADO-catalyzed exhaustive aerobic oxidations of 1,2-diols to α-keto acids. Combining oxidation with transamination using dl-2-phenylglycine led to the synthesis of free α-amino acids (AAs) in one pot. This method enables the rapid and flexible preparation of a variety of valuable unnatural AAs, such as fluorescent AAs, photoactivatable AAs, and other functional AAs for bioorthogonal reactions.
Preparative Asymmetric Synthesis of Canonical and Non-canonical α-amino Acids Through Formal Enantioselective Biocatalytic Amination of Carboxylic Acids
Dennig, Alexander,Blaschke, Fabio,Gandomkar, Somayyeh,Tassano, Erika,Nidetzky, Bernd
supporting information, (2019/02/09)
Chemical and biocatalytic synthesis of non-canonical α-amino acids (ncAAs) from renewable feedstocks and using mild reaction conditions has not efficiently been solved. Here, we show the development of a three-step, scalable and modular one-pot biocascade for linear conversion of renewable fatty acids (FAs) into enantiopure l-α-amino acids. In module 1, selective α-hydroxylation of FAs is catalyzed by the P450 peroxygenase P450CLA. By using an automated H2O2 supplementation system, efficient conversion (46 to >99%; TTN>3300) of a broad range of FAs (C6:0 to C16:0) into valuable α-hydroxy acids (α-HAs; >90% α-selective) is shown on preparative scale (up to 2.3 g L?1 isolated product). In module 2, a redox-neutral hydrogen borrowing cascade (alcohol dehydrogenase/amino acid dehydrogenase) allowed further conversion of α-HAs into l-α-AAs (20 to 99%). Enantiopure l-α-AAs (e.e. >99%) including the pharma synthon l-homo-phenylalanine can be obtained at product titers of up to 2.5 g L?1. Based on renewables and excellent atom economy, this biocascade is among the shortest and greenest synthetic routes to structurally diverse and industrially relevant ncAAs. (Figure presented.).
Direct Synthesis of Free α-Amino Acids by Telescoping Three-Step Process from 1,2-Diols
Inada, Haruki,Shibuya, Masatoshi,Yamamoto, Yoshihiko
supporting information, p. 709 - 713 (2019/01/25)
A practical telescoping three-step process for the syntheses of α-amino acids from the corresponding 1,2-diols has been developed. This process enables the direct synthesis of free α-amino acids without any protection/deprotection step. This method was also effective for the preparation of a 15N-labeled α-amino acid. 1,2-Diols bearing α,β-unsaturated ester moieties afforded bicyclic α-amino acids through intramolecular [3 + 2] cycloadditions. A preliminary study suggests that the resultant α-amino acids are resolvable by aminoacylases with almost complete selectivity.
PRODUCTION METHOD OF α-HYDROXYCARBOXYLIC ACID
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Paragraph 0042; 0045; 0063, (2016/10/07)
PROBLEM TO BE SOLVED: To provide an efficient production method of an α-hydroxycarboxylic acid in a mild condition, and to provide a production method of a biodegradable plastic from a raw material containing the α-hydroxycarboxylic acid. SOLUTION: In a synthesis method of an α-hydroxycarboxylic acid, which is a production method of the α-hydroxycarboxylic acid by oxidizing a 1,2-diol compound in a reaction system using a nitroxy radical including a skeleton represented by formula(1), water, and an organic solvent, the organic solvent is a compound unmixable with water (R1-R4 are respectively and independently 1-6C hydrocarbon groups). In the synthesis method of the α-hydroxycarboxylic acid, the reaction system has a pH value of 1.0-8.0, and includes a phosphate buffer solution or an acetate buffer solution, and at least one selected from a hypohalite and a halite is added to the reaction system, and further at least one selected from a tetraalkylammonium salt and a fatty acid is added thereto. COPYRIGHT: (C)2016,JPOandINPIT
Chemoselective catalytic oxidation of 1,2-diols to α-hydroxy acids controlled by TEMPO-ClO2 charge-transfer complex
Furukawa, Keisuke,Shibuya, Masatoshi,Yamamoto, Yoshihiko
supporting information, p. 2282 - 2285 (2015/05/13)
Chemoselective catalytic oxidation from 1,2-diols to α-hydroxy acids in a cat. TEMPO/cat. NaOCl/NaClO2 system has been achieved. The use of a two-phase condition consisting of hydrophobic toluene and water suppresses the concomitant oxidative cleavage. A study of the mechanism suggests that the observed selectivity is derived from the precise solubility control of diols and hydroxy acids as well as the active species of TEMPO. Although the oxoammonium species TEMPO+Cl- is hydrophilic, the active species dissolves into the organic layer by the formation of the charge-transfer (CT) complex TEMPO-ClO2 under the reaction conditions.
Kinetic resolution of mandelate esters via stereoselective acylation catalyzed by lipase PS-30
Chen, Peiran,Yang, Wenhong
supporting information, p. 2290 - 2294 (2014/04/17)
By using lipase PS-30 as catalyst, the kinetic resolution of a series of racemic mandelate esters has been achieved via stereoselective acylation. The value of kinetic enantiomeric ratio (E) reached up to 197.5. Substituent effect is briefly discussed.
Carboxylation with CO2 via brook rearrangement: Preparation of α-hydroxy acid derivatives
Mita, Tsuyoshi,Higuchi, Yuki,Sato, Yoshihiro
, p. 14 - 17 (2014/01/23)
In the presence of CsF, a wide range of α-substituted α-siloxy silanes were carboxylated under a CO2 atmosphere (1 atm) via Brook rearrangement. A variety of α-substituents including aryl, alkenyl, and alkyl groups were tolerated to afford α-hydroxy acids in moderate-to-high yields. One-pot synthesis from aldehydes using PhMe2SiLi and CO 2 was also possible, providing α-hydroxy acids without the isolation of an α-hydroxy silane.
Organocatalytic one-pot oxidative cleavage of terminal diols to dehomologated carboxylic acids
Shibuya, Masatoshi,Doi, Ryusuke,Shibuta, Takuro,Uesugi, Shun-Ichiro,Iwabuchi, Yoshiharu
supporting information, p. 5006 - 5009 (2013/01/15)
The organocatalytic one-pot oxidative cleavage of terminal 1,2-diols to one-carbon-unit-shorter carboxylic acids is described. The combination of 1-Me-AZADO (cat.), NaOCl (cat.), and NaClO2 caused smooth one-pot oxidative cleavage under mild conditions. A broad range of substrates including carbohydrates and N-protected amino diols were converted without epimerization. Terminal triols and tetraols respectively underwent cleavage of their C-2 and C-3 moieties to afford their corresponding two- and three-carbon-unit-shorter carboxylic acids.
Synthesis of α-hydroxy carboxylic acids via a nickel(II)- Catalyzed hydrogen transfer process
Tang, Guo,Cheng, Chien-Hong
supporting information; experimental part, p. 1918 - 1922 (2011/10/12)
A new catalytic system for β-alkylation of lactic acid with primary alcohols has been developed. In the presence of nickel(II) acetate tetrahydrate [Ni(OAc)2(H2O)4] and base, lactic acid reacts with primary alcohols to afford the corresponding coupled α-hydroxy carboxylic acids in good to excellent yields via a hydrogen transfer process without any hydrogen acceptor or hydrogen donor. Copyright
A practical and inexpensive 'convertible' isonitrile for use in multicomponent reactions
Le, Hoang V.,Fan, Lijun,Ganem, Bruce
, p. 2209 - 2211 (2011/05/09)
N-tert-Butylamides are readily converted into the corresponding carboxylic acids by simple nitrosation. The process, which occurs under mild nonaqueous conditions, leaves carboxylic esters untouched and transforms multicomponent reaction products into useful building blocks for further synthetic elaboration.
