25488-27-1

Upstream product

• 171597-45-8 (2S,3R)-2-acetylamino-3-phenyl-butyric acid methyl ester 
• 25488-26-0 erythro-D-(2R,3R)-β-methylphenylalanine 
• 256442-52-1 methyl (2S,3R)-2-benzamide-3-phenylbutanoate 
• 69015-75-4 (Z)-2-phenyl-4-(α-phenylethylidene)-5-(4H)-oxazolone 
• 4593-90-2 3-phenylbutyric acid 
• 128677-87-2 (4S)-N-[(3S)-phenylbutanoyl]-4-phenylmethyl-1,3-oxazolidin-2-one 
• 143251-56-3 (R)-4-Benzyl-3-((2S,3R)-2-bromo-3-phenyl-butyryl)-oxazolidin-2-one 
• 772-14-5 (R)-3-phenylbutyric acid 
• 128677-89-4 (R)-4-Benzyl-3-((S)-3-phenyl-butyryl)-oxazolidin-2-one 
• 585-71-7 (1-bromoethyl)benzne 
• 56-40-6 glycine 
• 22122-01-6 2-Aethoxy-3-methyl-zimtsaeure-aethylester 
• 4658-69-9 α-keto-β-phenylbutyric acid 
• 495-69-2 Hippuric Acid 

Downstream Products

• 145432-51-5 (βR)-N-(tert-butoxycarbonyl)-β-methyl-L-phenylalanine 
• 321524-83-8 (2S,3R)-N-(9-fluorenylmethoxycarbonyl)-β-methylphenylalanine 
• 25488-26-0 erythro-D-(2R,3R)-β-methylphenylalanine 
• 321524-72-5 N-Z-3-(2S,3R)-β-methylphenylalanine 

Relevant academic research and scientific papers

Stereoselective Synthesis of β-Branched Aromatic α-Amino Acids by Biocatalytic Dynamic Kinetic Resolution**

β-Branched noncanonical amino acids are valuable molecules in modern drug development efforts. However, they are still challenging to prepare due to the need to set multiple stereocenters in a stereoselective fashion, and contemporary methods for the synthesis of such compounds often rely on the use of rare-transition-metal catalysts with designer ligands. Herein, we report a highly diastereo- and enantioselective biocatalytic transamination method to prepare a broad range of aromatic β-branched α-amino acids. Mechanistic studies show that the transformation proceeds through dynamic kinetic resolution that is unique to the optimal enzyme. To highlight its utility and practicality, the biocatalytic reaction was applied to the synthesis of several sp3-rich cyclic fragments and the first total synthesis of jomthonic acid A.

Total Synthesis of Mannopeptimycins α and β

The mannopeptimycins are a class of glycopeptide natural products with unusual structures and potent antibiotic activity against a range of Gram-positive multidrug-resistant bacteria. Their cyclic hexapeptide core features a pair of unprecedented β-hydroxyenduracididines (l- and d-βhEnd), an O-glycosylated d-Tyr carrying an α-linked dimannose, and a β-methylated Phe residue. The d-βhEnd unit also carries an α-linked mannopyranose at the most hindered N of its cyclic guanidine ring. Herein, we report the first total synthesis of mannopeptimycin α and β with fully elaborated N- and O-linked sugars. Critically, a gold-catalyzed N-glycosylation of a d-βhEnd substrate with a mannosyl ortho-alkynylbenzoate donor enabled the synthesis of the most challenging N-Man-d-βhEnd unit with excellent efficiency and stereoselectivity. The l-βMePhe unit was prepared using a Pd-catalyzed C-H arylation method. The l-βhEnd, d-Tyr(di-Man), and l-βMePhe units were prepared in gram quantities. A convergent assembly of the cyclic peptide scaffold and a single global hydrogenolysis deprotection operation provided mannopeptimycin α and β.

(2R,1'S,2'R)- And (2S,1'S,2'R)-3-[2-mono(di,tri)fluoromethylcyclopropyl] alanines and their incorporation into hormaomycin analogues

Efficient and scalable syntheses of enantiomerically pure (2 R ,1' S ,2' R )- and (2 S ,1' S ,2' R )-3-[2-mono(di,tri)fluoromethylcyclopropyl] alanines 9a - c , as well as allo-D-threonine ( 4 ) and ( 2 S,3R)-β-methylphenylalanine (3), using the Belokon' approach with (S )- and (R )-2-[( N-benzylprolyl)amino]benzophenone [(S)- and (R)-10 ] as reusable chiral auxiliaries have been developed. Three new fluoromethyl analogues of the naturally occurring octadepsipeptide hormaomycin ( 1 ) with (fluoromethylcyclopropyl) alanine moieties have been synthesized and subjected to preliminary tests of their antibiotic activity.

Asymmetric synthesis of (2S,3S)- and (2R,3R)-α,β-dialkyl- α-amino acids via alkylation of chiral nickel(II) complexes of aliphatic α-amino acids with racemic α-alkylbenzyl bromides

This study has demonstrated that the stereochemical outcome of the direct alkylation of nickel(II) complexes derived from chiral Schiff bases of glycine, alanine, 2-aminobutyric acid, and leucine with racemic α-methylbenzyl bromide depends on the steric bulk of the corresponding amino acid residue. In particular, the alkylation of the alanine complex was found to proceed with a synthetically useful level (90% de) of stereoselectivity offering a concise synthesis of enantiomerically pure (2S,3S)- or (2R,3R)-α,α- dimethylphenylalanines. Georg Thieme Verlag Stuttgart.

An efficient and stereodivergent synthesis of threo- and erythro-β-methylphenylalanine. Resolution of each racemic pair by semipreparative HPLC

threo and erythro diastereoisomers of the constrained amino acid (βMe)Phe can be obtained separately on a multigram scale through a three-step synthesis from the corresponding Z and E isomers of 2-phenyl-4(α-phenylethylidene)-5(4H)-oxazolone. The 5(4H)-ox

Stereoinversion of β- and γ-substituted α-amino acids using a chemo-enzymatic oxidation-reduction procedure

Both D- and L-β- and γ-substituted α-amino acids can be interconverted to their respective L- and D- diastereoisomers by treatment with an enantioselective amino acid oxidase and a chemical reducing agent.

Catalytic asymmetric hydrogenation of α-(acetamido)acrylates using TRAP trans-chelating chiral bisphosphine ligands: Remarkable effects of ligand P-substituent and hydrogen pressure on enantioselectivity

The catalytic asymmetric hydrogenation of α-(acetamido)acrylates was carded out with the rhodium complexes prepared from [Rh(cod)2]BF4 and trans-chelating chiral bisphosphine ligands, (S,S)-2,2'-bis[(R)-1-(dialkylphosphino)ethyl]-1,1

A new strategy for the synthesis of four individual isomers of β-methylphenylalanine

The application of an allylic strain effect in boron enolates and asymmetric Michael-like addition/electrophilic bromination reactions is reported for the asymmetric synthesis of the individual isomers of unusual constrained amino acids. For β-substituted

Exploration for Large-scale Stereoselective Synthesis of Unusual Amino Acids by using 4-Phenyoxazolidin-2-one as a New Chiral Resolution Reagent

Individual isomers of β-branched α-amino acids have been stereoselectively and asymmetrically synthesized in high yield by a new method which uses 4-phenyloxazolidin-2-one as a novel chiral resolution reagent acting simultaneously as the auxiliary.

Asymmetric synthesis of unusual amino acids: An efficient synthesis of optically pure isomers of β-methylphenylalanine

Substitution of the diastereotopic β-hydrogens of many α-amino acids provides an approach to the three dimensional topographic control of peptide structure. Asymmetric synthesis of the desired amino acids is needed to facilitate these studies. All four in