13398-26-0Relevant articles and documents
Synthesis of optically active α-methylamino acids and amides through biocatalytic kinetic resolution of amides
Wang, Mei-Xiang,Liu, Jun,Wang, De-Xian,Zheng, Qi-Yu
, p. 2409 - 2416 (2005)
Catalyzed by Rhodococcus sp. AJ270, a nitrile hydratase and amidase containing microbial whole-cell catalyst, under very mild conditions, a number of racemic α-methylamino amides were resolved into the corresponding optically active (S)-(+)-α-methylamino acids and (R)-(-)-α- methylamino amides. The steric requirement of the amidase against α-amino phenylacetamides bearing methyl group(s) at α-amino nitrogen and/or α-carbon was also studied. Coupled with the chemical hydrolysis of amide, the biotransformation process provided a direct synthesis of α-methylamino acids in both enantiomeric forms from readily available racemic amides.
Asymmetric α-arylation of amino acids
Leonard, Daniel J.,Ward, John W.,Clayden, Jonathan
, p. 105 - 109 (2018/10/15)
Quaternary amino acids, in which the α-carbon that bears the amino and carboxyl groups also carries two carbon substituents, have an important role as modifiers of peptide conformation and bioactivity and as precursors of medicinally important compounds1,2. In contrast to enantioselective alkylation at this α-carbon, for which there are several methods3–8, general enantioselective introduction of an aryl substituent at the α-carbon is synthetically challenging9. Nonetheless, the resultant α-aryl amino acids and their derivatives are valuable precursors to bioactive molecules10,11. Here we describe the synthesis of quaternary α-aryl amino acids from enantiopure amino acid precursors by α-arylation without loss of stereochemical integrity. Our approach relies on the temporary formation of a second stereogenic centre in an N′-arylurea adduct12 of an imidazolidinone derivative6 of the precursor amino acid, and uses readily available enantiopure amino acids both as a precursor and as a source of asymmetry. It avoids the use of valuable transition metals, and enables arylation with electron-rich, electron-poor and heterocyclic substituents. Either enantiomer of the product can be formed from a single amino acid precursor. The method is practical and scalable, and provides the opportunity to produce α-arylated quaternary amino acids in multi-gram quantities.
Asymmetric α-arylation of amino acids
Leonard, Daniel J.,Ward, John W.,Clayden, Jonathan
, p. 105 - 109 (2019/10/21)
Quaternary amino acids, in which the α-carbon that bears the amino and carboxyl groups also carries two carbon substituents, have an important role as modifiers of peptide conformation and bioactivity and as precursors of medicinally important compounds1,2. In contrast to enantioselective alkylation at this α-carbon, for which there are several methods3–8, general enantioselective introduction of an aryl substituent at the α-carbon is synthetically challenging9. Nonetheless, the resultant α-aryl amino acids and their derivatives are valuable precursors to bioactive molecules10,11. Here we describe the synthesis of quaternary α-aryl amino acids from enantiopure amino acid precursors by α-arylation without loss of stereochemical integrity. Our approach relies on the temporary formation of a second stereogenic centre in an N′-arylurea adduct12 of an imidazolidinone derivative6 of the precursor amino acid, and uses readily available enantiopure amino acids both as a precursor and as a source of asymmetry. It avoids the use of valuable transition metals, and enables arylation with electron-rich, electron-poor and heterocyclic substituents. Either enantiomer of the product can be formed from a single amino acid precursor. The method is practical and scalable, and provides the opportunity to produce α-arylated quaternary amino acids in multi-gram quantities.
UNNATURAL AMINO ACIDS
-
Paragraph 00190; 00296, (2018/07/05)
The present invention relates to a process for the preparation compounds of Formula (I): Formula (I) wherein X, Z, Q, Ar, R1, R2, R3 and R4 are each as defined herein. The present invention also relates to processes for the preparation of the compounds of quaternary amino acids and hydantions, to compound of Formula(I), to intermediate compounds of Formula (II), to quaternary amino acid compounds of Formula (III) and to hydantoin compounds of Formula (IV).
Nitrilases, nucleic acids encoding them and methods for making and using them
-
Page/Page column 52, (2016/01/09)
The invention relates to nitrilases and to nucleic acids encoding the nitrilases. In addition methods of designing new nitrilases and method of use thereof are also provided. The nitrilases have increased activity and stability at increased pH and temperature.
Mitsunobu approach to the synthesis of optically active α,α-disubstituted amino acids
Green, Jonathan E.,Bender, David M.,Jackson, Stona,O'donnell, Martin J.,Mccarthy, James R.
supporting information; experimental part, p. 807 - 810 (2009/08/08)
Chiral tertiary α-hydroxy esters of known stereochemical configuration were transformed to α-azido esters by Mitsunobu reaction with HN3. Optimization of this reaction was shown to proceed at room temperature with high chemical yield using 1,1-(azodicarbonyl)dipiperidine (ADDP) and trimethylphosphine (PMe3). Complete inversion of configuration was observed at the α-carbon. Several α,α- disubstituted amino acids were synthesized in high overall chemical yield and optical purity.
Asymmetric Strecker reaction of ketoimines catalyzed by a novel chiral bifunctional N,N′-dioxide
Huang, Xiao,Huang, Jinglun,Wen, Yuehong,Feng, Xiaoming
, p. 2579 - 2584 (2007/10/03)
A novel bifunctional N,N′-dioxide derived from L-prolinamide was employed to catalyze the enantioselective Strecker reaction of a range of N-tosyl ketoimines, and an effective additive was used to improve the reactivity (up to 99% yield) as well as the en
Method for preparing chiral amino acids
-
Page column 11, (2008/06/13)
The invention concerns a novel method for preparing chiral amino acids of formula (I) characterised in that it consists in contracting a racemic hydantoin of formula (II) with an enantiomeric splitting agent.
Efficient biocatalytic synthesis of highly enantiopure α-alkylated arylglycines and amides
Wang, Mei-Xiang,Lin, Shuan-Jun,Liu, Jun,Zheng, Qi-Yu
, p. 439 - 445 (2007/10/03)
A number of racemic α-alkylarylglycine amides including 1-amino-1-carbamoyl-1,2,3,4-tetrahydronaphthalene underwent efficient biocatalytic hydrolysis under very mild conditions to afford the corresponding (S)-α-alkylarylglycines and (R)-α-alkylarylglycine
