67942-91-0

Upstream product

• 51127-16-3 rac-4-ethyl-2-phenyloxazol-5(4H)-one 
• 60027-58-9 (Z)-α-N-benzoylamino-2-butenoic acid methylester 
• 65499-78-7 (Z)-α-N-benzoylamino-2-butenoic acid 
• 98-88-4 benzoyl chloride 
• 2623-91-8 (R)-2-aminobutyric acid 
• 575465-48-4 (4S)-4-benzyl-3-{[(1R)-1-(1,3-dioxolan-2-yl)propyl](phenyl)carboxamido}-2-oxo-1,3-oxazolane 
• 575465-50-8 2-[(1R)-1-(phenylcarboxamido)propyl]-1,3-dioxolane 
• 575465-49-5 2-hydroxyethyl (2R)-2-(phenylcarboxamido)butanoate 
• 87069-72-5 (R)-N-(1-hydroxybutan-2-yl)benzamide 
• 79893-94-0 N-benzoyl-α-aminobuttersauremethylester 
• 7469-23-0 N-benzoyl-DL-allothreonine 
• 7469-23-0 N-benzoyl-DL-threonine 
• 2835-81-6 2-aminobutanoic acid 
• 201230-82-2 carbon monoxide 

Downstream Products

• 57357-34-3 (Di-N-benzoyl-α-aminobutyryloxyjod)-benzol 
• 81216-98-0 N-[1-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-ylcarbamoyl)-propyl]-benzamide 
• 51127-16-3 rac-4-ethyl-2-phenyloxazol-5(4H)-one 
• 28358-79-4 N-propionyl-benzamide 
• 5959-29-5 S-(+)-2-amino-n-butyric acid hydrochloride 
• 1204591-61-6 C₁₄H₁₇NO₃ 
• 1204591-68-3 C₁₄H₁₇NO₃ 
• 67607-42-5 R-(-)-2-amino-n-butyric acid hydrochloride 
• 6257-49-4 (2R)-2-(benzylamino)butan-1-ol 

Relevant academic research and scientific papers

Asymmetric Aza-Diels-Alder Reactions of in Situ Generated β,β-Disubstituted α,β-Unsaturated N-H Ketimines Catalyzed by Chiral Phosphoric Acids

A novel asymmetric synthesis of dihydropyridinones with vicinal quaternary stereocenters has been realized by asymmetric aza-Diels-Alder reactions of 3-amido allylic alcohols with oxazolones enabled by chiral phosphoric acid catalysis. A series of aryl/alkyl- and alkyl/alkyl-disubstituted 3-amido allylic tertiary alcohols and 4-substituted oxazolones could be well tolerated in these reactions, producing dihydropyridinones with excellent diastereoselectivities and high enantioselectivities. Mechanistic study and control experiments were performed to shed light on the reaction mechanism, in which a configurationally defined β,β-disubstituted α,β-unsaturated N-H ketimine was proposed as the key intermediate.

Bifunctional squaramide-catalyzed synthesis of chiral dihydrocoumarins via ortho-quinone methides generated from 2-(1-tosylalkyl)phenols

A bifunctional squaramide-catalyzed reaction of azlactones with o-quinone methides in situ generated from 2-(1-tosylalkyl)-phenols has been successfully developed under basic conditions, providing an efficient and mild access to chiral dihydrocoumarins bearing adjacent tertiary and quaternary stereogenic centers in high yields with excellent diastereo- and enantioselectivities.

Palladium-Catalyzed Ortho-Alkoxylation of N-Benzoyl α-Amino Acid Derivatives at Room Temperature

An efficient palladium-catalyzed ortho-alkoxylation of N-benzoyl α-amino acid derivatives at room temperature has been explored. This novel transformation, using amino acids as directing groups, Pd(OAc)2 as catalyst, alcohols as the alkoxylation reagents, and PhI(OAc)2 as the oxidant, showed wide generality, good functional tolerance, and high monoselectivity and regioselectivity.

Regiodivergent Enantioselective γ-Additions of Oxazolones to 2,3-Butadienoates Catalyzed by Phosphines: Synthesis of α,α-Disubstituted α-Amino Acids and N,O-Acetal Derivatives

Phosphine-catalyzed regiodivergent enantioselective C-2- and C-4-selective γ-additions of oxazolones to 2,3-butadienoates have been developed. The C-4-selective γ-addition of oxazolones occurred in a highly enantioselective manner when 2-aryl-4-alkyloxazol-5-(4H)-ones were employed as pronucleophiles. With the employment of 2-alkyl-4-aryloxazol-5-(4H)-ones as the donor, C-2-selective γ-addition of oxazolones took place in a highly enantioselective manner. The C-4-selective adducts provided rapid access to optically enriched α,α-disubstituted α-amino acid derivatives, and the C-2-selective products led to facile synthesis of chiral N,O-acetals and γ-lactols. Theoretical studies via DFT calculations suggested that the origin of the observed regioselectivity was due to the distortion energy that resulted from the interaction between the nucleophilic oxazolide and the electrophilic phosphonium intermediate.

Asymmetric palladium(II)-catalyzed cascade reaction giving quaternary amino succinimides by 1,4-addition and a nef-type reaction

Simple starting materials, high-value products: A dinuclear ferrocene-based PdII complex transforms mixtures of racemic N-benzoyl α-amino acids, nitroolefins, acetic anhydride, and manganese acetate into biologically interesting quaternary amin

Polyclonal antibodies: A cheap and efficient tool for screening of enantioselective catalysts

Enantioselective polyclonal antibodies have been produced and characterized to develop a high-throughput screening method for lipase activity fingerprinting, with a view to the enantioselective hydrolysis of azlactones.

Bispalladacycle-catalyzed Michael addition of in situ formed azlactones to enones

The development and further evolution of the first catalytic asymmetric conjugate additions of azlactones as activated amino acid derivatives to enones is described. Whereas the first-generation approach started from isolated azlactones, in the second-generation approach the azlactones could be generated in situ starting from racemic N-benzoylated amino acids. The third evolution stage could make use of racemic unprotected α-amino acids to directly form highly enantioenriched and diastereomerically pure masked quaternary amino acid products bearing an additional tertiary stereocenter. The step-economic transformations were accomplished by cooperative activation by using a robust planar chiral bis-Pd catalyst, a Br?nsted acid (HOAc or BzOH; Ac=acetyl, Bz=benzoyl), and a Br?nsted base (NaOAc). In particular the second- and third-generation approaches provide a rapid and divergent access to biologically interesting unnatural quaternary amino acid derivatives from inexpensive bulk chemicals. In that way highly enantioenriched acyclic α-amino acids, α-alkyl proline, and α-alkyl pyroglutamic acid derivatives could be prepared in diastereomerically pure form. In addition, a unique way is presented to prepare diastereomerically pure bicyclic dipeptides in just two steps from unprotected tertiary α-amino acids. Flourishing step economy: The evolution of the catalytic asymmetric addition of azlactones to enones is described. The first-generation approach started from isolated azlactones. In the second-generation approach azlactones could be generated in situ from racemic N-benzoylated amino acids. The third evolution stage could directly use racemic unprotected α-amino acids to form a large number of highly enantioenriched quaternary amino acids derivatives (see figure). Copyright

Asymmetric synthesis of α- And β-amino acids by diastereoselective addition of triorganozincates to N-(tert-butanesulfinyl) imines

The diastereoselective addition of triorganozincates to (R)-N-(tert-butanesulfinyl)imines has been used as a key step to achieve the synthesis of highly enantiomerically enriched N-protected α- and β-amino acids. Desulfinylation of the addition products followed by benzoylation of the nitrogen atom of the obtained primary amines and oxidation of one of the substituents on the carbon atom connected to the nitrogen complete the sequence. Using the same configuration in the sulfinyl chiral auxiliary, α-amino acids with the (R) or the (S) configuration can be prepared by choosing the proper combination of imine and organozincate. α,α- Disubstituted α-amino esters with high enantiomeric purity can also be prepared when α-imino esters are the starting substrates.

Bispalladacycle-catalyzed bronsted acid/base-promoted asymmetric tandem azlactone formation-michael addition

Cooperative activation by a soft bimetallic catalyst, a hard Bronsted acid, and a hard Bronsted base has allowed the formation of highly enantioenriched, diastereomerically pure masked α-amino acids with adjacent quaternary and tertiary stereocenters in a single reaction starting from racemic N-benzoylated amino acids. The products can, for example, be used to prepare bicyclic dipeptides.

PREPARATION OF (S)-2-AMINOBUTYRIC ACID

Processes for the preparation of (S)-2-aminobutyric acid, embodiments including selective hydrolysis of racemic N-protected-2-aminobutyric acid using an acylase enzyme, such as one derived from Thermococcus litorolis or Aspergillus melleus.