- New enzymatic methods for the synthesis of primary α-aminonitriles and unnatural α-amino acids by oxidative cyanation of primary amines with d-amino acid oxidase from porcine kidney
-
Oxidation of amino groups in amines or amino acids activates the sp3 Cα-H bond to form imines, making the alpha carbon atom a preferable target for nucleophilic reagents such as cyanide. Therefore, we focused on the oxidase reaction for the production of primary α-aminonitriles via imines. d-Amino acid oxidase from porcine kidney (pkDAO) and l-amino acid oxidase from Crotalus atrox catalyzed the synthesis of 2-amino-2-cyano-3-phenylpropanoic acid from phenylalanine and potassium cyanide (KCN). Mutant pkDAO (Y228L/R283G) catalyzed the synthesis of racemic-2-methyl-2-phenylglycinonitrile from (R)-α-methylbenzylamine and KCN. Based on these results, we developed a new cascade reaction for the synthesis of unnatural α-amino acids from primary amines using mutant pkDAO and nitrilase AY487533. This is the first report of the enzymatic synthesis of primary α-aminonitriles and unnatural α-amino acids. These methods will contribute widely to the synthesis of primary α-aminonitriles and unnatural α-amino acids in aqueous systems.
- Kawahara, Nobuhiro,Yasukawa, Kazuyuki,Asano, Yasuhisa
-
supporting information
p. 418 - 424
(2017/08/14)
-
- Palladium Catalyzed C-Arylation of Amino Acid Derived Hydantoins
-
Palladium(II) trifluoroacetate (5 mol %) catalyzes the C-arylation of N,N-disubstituted hydantoins by aryl iodides in good yield. The reaction proceeds through base-promoted enolization of the amino acid derived hydantoins, and the resulting 5,5-disubstituted hydantoins may be deprotected at one or both N atoms to yield biologically active structures or alternatively hydrolyzed to the parent α-aryl α-amino acids. The reaction is successful with a variety of parent amino acids and a range of electron-rich and electron-poor aryl iodides.
- Fernández-Nieto, Fernando,Mas Roselló, Josep,Lenoir, Simone,Hardy, Simon,Clayden, Jonathan
-
p. 3838 - 3841
(2015/08/18)
-
- NOVE PHENYL/PYRIDINE SERIES SUBSTITUED BY HYDROXYETHYLAMINO FOR THE TREATMENT OF CANCER
-
The invention provides novel compounds having the general formula (I) wherein R1, R2, R3, R4, R5, R6, R7 and W are as described herein, compositions including the compounds and methods of using the compounds.
- -
-
Page/Page column 68; 69
(2014/07/22)
-
- Bifunctional iminophosphorane organocatalysts for enantioselective synthesis: Application to the ketimine nitro-Mannich reaction
-
The design, synthesis, and development of a new class of modular, strongly basic, and tunable bifunctional Bronsted base/H-bond-donor organocatalysts are reported. These catalysts incorporate a triaryliminophosphorane as the Bronsted basic moiety and are readily synthesized via a last step Staudinger reaction of a chiral organoazide and a triarylphosphine. Their application to the first general enantioselective organocatalytic nitro-Mannich reaction of nitromethane to unactivated ketone-derived imines allows the enantioselective construction of β-nitroamines possessing a fully substituted carbon atom. The reaction is amenable to multigram scale-up, and the products are useful for the synthesis of enantiopure 1,2-diamine and α-amino acid derivatives.
- Nunez, Marta G.,Farley, Alistair J. M.,Dixon, Darren J.
-
p. 16348 - 16351
(2013/12/04)
-
- Intramolecular arylation of amino acid enolates
-
Dianionic enolates formed from N′-aryl urea derivatives of amino acids undergo intramolecular C-arylation by attack of the enolate anion on the N′-aryl ring, leading to a hydantoin derivative of a quaternary amino acid. In situ IR studies allow identification of four intermediates on the reaction pathway.
- Atkinson, Rachel C.,Leonard, Daniel J.,Maury, Julien,Castagnolo, Daniele,Volz, Nicole,Clayden, Jonathan
-
supporting information
p. 9734 - 9736
(2013/10/21)
-
- Asymmetric synthesis of deuterated and fluorinated aromatic α,α-disubstituted amino acid derivatives
-
We herein present organocatalytic approaches to synthesize fluorinated and deuterated α-substituted phenylglycine derivatives. Whereas the addition of diethyl azodicarboxylate to fluorinated α-substituted aldehydes furnishes chiral non-racemic compounds, the use of chloramine-T as a nitrogen source represents a rapid access to sulfamidated fluorinated amino acid precursors. Additionally, further functionalization was achieved through the palladium-catalyzed coupling of a p-bromosubstituted aldehyde with a range of fluorine or deuterium-containing boronic acids. Oxidation of the aldehyde function and cleavage of the protection group of the nitrogen give way to the free fluorinated unnatural amino acids.
- Hartmann, Caroline E.,Baumann, Thomas,Baechle, Michael,Braese, Stefan
-
scheme or table
p. 1341 - 1349
(2010/10/21)
-
- Versatile synthesis of free and N-benzyloxycarbonyl-protected 2,2-disubstituted taurines
-
An effective and versatile method was developed to synthesize N-benzyloxycarbonyl-protected and free 2,2-disubstituted taurines. Several novel 2,2-disubstituted taurines, including aliphatic/aromatic and cyclic/acyclic derivatives, were obtained, which demonstrates the generality of this method. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Wang, Boyuan,Zhang, Wei,Zhang, Leilei,Du, Da-Ming,Liu, Gang,Xu, Jiaxi
-
p. 350 - 355
(2008/09/18)
-
- NOVEL 2-AMINO-IMIDAZOLE-4-ONE COMPOUNDS AND THEIR USE IN THE MANUFACTURE OF A MEDICAMENT TO BE USED IN THE TREATMENT OF COGNITIVE IMPAIRMENT, ALZHEIMER’S DISEASE, NEURODEGENERATION AND DEMENTIA
-
This invention relates to novel compounds having the structural formula I below and to their pharmaceutically acceptable salts, compositions and methods of use. These novel compounds provide a treatment or prophylaxis of cognitive impairment, Alzheimer Di
- -
-
Page/Page column 75
(2008/06/13)
-
- Sulfamidation of 2-arylaldehydes and ketones with chloramine-T
-
A series of aliphatic and aromatic carbonyl compounds has been transformed into the corresponding sulfamidated products by means of amine-catalyzed nitrene transfer of chloramine-T. Depending on the residues R, either α-sulfamidation in the case of aromat
- Baumann, Thomas,Bachle, Michael,Brase, Stefan
-
p. 3797 - 3800
(2007/10/03)
-
- Direct asymmetric α-sulfamidation of α-branched aldehydes: A novel approach to enamine catalysis
-
Proline-catalysed reactions between α-branched aldehydes and sulfonyl azides provide scalemic configurationally stabilised α-sulfamidated products with ee values of up to 86%. The reactions can also be carried out in a one-pot fashion, with catalyst, alde
- Vogt, Henning,Baumann, Thomas,Nieger, Martin,Braese, Stefan
-
p. 5315 - 5338
(2007/10/03)
-
- Structure-Activity Study of Tripeptide Thrombin Inhibitors Using α-Alkyl Amino Acids and Other Conformationally Constrained Amino Acid Substitutions
-
In our continuing effort to design novel thrombin inhibitors, a series of conformationally constrained amino acids (e.g. α-alkyl, N-alkyl cyclic, etc.) were utilized in a systematic structure-activity study of the P3, P2, and P1 positions of tripeptide arginal thrombin inhibitors.Early examples of this effort include: D-MePhe-Pro-Arg-H (15), Boc-D-Phg-Pro-Arg-H (18), D-1-Tiq-Pro-Arg-H (23, D-1-Tiq = D-1,2,3,4-tetrahydroisoquinolin-1-ylcarbonyl), and Boc-D-Phe-Pro-Arg-H (25).10a,20 The current work clarifies the contribution of each residue of the tripeptide arginals toward the potent and selective inhibition of thrombin relative to that of t-PA and plasmin.The α-methylarginal modification in the P1 residue resulted in analogs 30 (D-MePhe at P3) and 32 (D-1-Tiq at P3) which had lower potency toward thrombin while exhibiting improved selectivity.Analogs modified at the P2 site were found to be very sensitive to the conformational changes induced by variations in side chain ring size with the flexible pipecolinic acid 31 being 2 orders of magnitude less potent at thrombin inhibition than the conformationally constrained azetidine analog 20.Examination of the P3 binding region indicated that α-alkylphenylglycine residues resulted in a tendency to exhibit substantional improvements in selectivity over the nonalkylated residues.Combinations of optimal P3 and P2 changes led to compounds TFA-D-Phg(αEt)-Azt-Arg-H (16), TFA-D-Phg(αMe)-Azt-Arg-H (17), Ac-D-Phg(αMe)-Azt-Arg-H (21), TFA-D-Phg(αMe)-Pro-Arg-H (27), 30, and 32, which are clearly more selective for thrombin versus plasmin than the nonconformationally constrained compounds.
- Shuman, Robert T.,Rothenberger, Robert B.,Campbell, Charles S.,Smith, Gerald F.,Gifford-Moore, Donetta S.,et al.
-
p. 4446 - 4453
(2007/10/03)
-
- N-SUBSTITUTED HETEROCYCLIC DERIVATIVES, THEIR PREPARATION AND THE PHARMACEUTICAL COMPOSITIONS IN WHICH THEY ARE PRESENT
-
The invention relates to N-substituted heterocyclic derivatives and its salts. These derivatives have the formula (I) in which the substituents are as defined in the specification. Application: Angiotensin II antagonists
- -
-
-