174007-71-7

Upstream product

• 63-91-2 L-phenylalanine 
• 2627-86-3 (S)-1-phenyl-ethylamine 
• 146492-49-1 tert-butyl N-((1S)-1-benzyl-2-oxo-2-{[(1S)-1-phenylethyl]amino}ethyl)carbamate 
• 13734-34-4 N-tert-butoxycarbonyl-L-phenylalanine 
• 1161-13-3 N-Cbz-L-Phe 
• 3397-32-8 N-(benzyloxycarbonyl)-phenylalanine-N-hydroxysuccinimide ester 
• 17430-32-9 N--(S)-α-methylbenzylamine 

Downstream Products

• 79869-83-3 N--(S)-α-methylbenzylamine 
• 184956-16-9 {(R)-3-Methyl-1-[(S)-2-phenyl-1-((S)-1-phenyl-ethylcarbamoyl)-ethylcarbamoyl]-butyl}-carbamic acid tert-butyl ester 

Relevant academic research and scientific papers

Highly modular dipeptide-like organocatalysts for direct asymmetric aldol reactions in brine

A novel series of dipeptide-like organocatalysts derived from proline, amino acids and primary amines have been prepared for direct asymmetric aldol reactions between various aromatic aldehydes and acetone to afford aldol products in good yields (up to 82%) and moderate enantioselectivities (up to 67% ee) with only 1 mol% of catalyst-loading in brine. Under the same conditions, the direct asymmetric aldol reactions of aromatic aldehydes and cyclohexanone give aldol products with high yields (up to 91%) and moderate to good enantioselectivities (up to 88% ee) and excellent diastereoselectivities (up to 99% dr). These organocatalysts are easily synthesized from commercially available materials in multi-gram scale with high modularity in their structural and stereogenic properties.

Nickel complexes from α-amino amides as efficient catalysts for the enantioselective Et2Zn addition to benzaldehyde

Ni2+ complexes derived from simple α-amino amides catalyze very efficiently the addition of Et2Zn to benzaldehyde, giving (S)-1-phenylethanol as the major isomer in most cases (94% yield, 97% ee for R=Bn). The nature of the substituent on the amide nitrogen atom seems to play a key role in determining the asymmetric induction observed.

Chymotrypsin inhibitory conformation induced by amino acid side chain-side chain intramolecular CH/π interaction

Dipeptide amides H-D-Leu-Phe-NH-R have been found to assume a conformation induced by the CH/π interaction and to inhibit chymotrypsin strongly. A series of benzyl amide derivatives H-D-Leu-Phe-NH-[CH2]n-C6H5 (n = 0-4) have been assayed for chymotrypsin. They inhibit the enzyme in a competitive manner and the highest inhibition is achieved by the amide of n = 1 (Ki = 3.6 × 10-6 M). The activity enhancement is dependent upon the length of methylene chain, not upon the increase in molecular hydrophobicity, indicating the presence of an optimal distance between dipeptide backbone and C-terminal phenyl group for chymotrypsin inhibition. The C-terminal phenyl group has been found to interact with chymotrypsin stereospecifically. The R-isomer of H-D-Leu-Phe-NH-CH(CH3)-C6H5 is as active as the benzyl amide, while the S-isomer is about twenty-fold less active. When the fluorine atom is introduced at a para-position of the C-terminal phenyl group, the resulting dipeptide H-D-Leu-Phe-NH-CH2-C6H4F-p exhibits about six-times increased inhibitory activity (Ki = 6.1 × 107 M; this dipeptide is one of the most potent chymotrypsin inhibitors to date). 1H NMR conformational analyses of these dipeptide amide derivatives show the CH/π interaction between D-Leu-isobutyl and Phe-phenyl as a key structural element for chymotrypsin inhibition. These structural examinations strongly suggest that in the inhibitory conformation the C-terminal phenyl group fits the chymotrypsin S1 site, while the hydrophobic core constructed by D-Leu-Phe CH/π interaction fits the chymotrypsin S2 or S1′ site.

Stereochemical Effects in Mass Spectrometry 7. Determination of Absolute Configuration of Some Organic Molecules by Reaction Mass Spectrometry

It was found that in the chemical ionization (isobutane) mass spectra of some asymmetric secondary alcohols and α-amino acids, when a pair of enantiomers (such as R- and S-2-phenylbutyric anhydride, R- and S-mandelic acid, R- and S-2-methylbutanoic acid or R- and S-α-phenyl ethyl amine) were used as reaction reagents, the relative abundances of characteristic ions formed by the stereoselective reaction between sample and reagent of the same configuration were much higher than those ions formed by the sample and a reagent of a different configuration. The absolute configuration of the sample molecule may be predicted by examination of mass spectra of the sample measured with R- and S-reagent respectively.This approach proved to be a convenient way for determination of the absolute configurations of organic molecules on a micromole level by mass spectrometry.

Asymmetric Hydrogenation Catalyzed by the (Achiral Base)bis(dimethylglyoximato)cobalt(II)-Chiral Cocatalyst System. The Preparation of a New Type of Chiral Cocatalyst and Its Application to the Asymmetric Hydrogenation of Methyl N-(Acetylamino)acrylate and Benzil

As a new type of chiral cocatalyst in the achiral base-coordinated bis(dimethylglyoximato)cobalt(II)-chiral cocatalyst system, tertiary amines with an amide group at α- or β-carbon were prepared, and asymmetric hydrogenation was examined by using them.The optical yield reached 34.5percent enantiomeric excess(ee) by using N--(R)-α-methylbenzylamine; this is the highest value attained so far in the asymmetric hydrogenation of methyl N-(acetylamino)acrylate with this system.The enantioselectivity in the hydrogenation of methyl N-(acetylamino)acrylate was reversed with a configurational alteration of the α-methylbenzylamine moiety of N--α-methylbenzylamine, while it was not reversed in the hydrogenation of benzil by the configurational alteration.From these facts, it is deduced that the hydrogen bond between amide groups of the chiral amino carboxamides and methyl N-(acetylamino)acrylate may act as an attractive force to enhance the enantioselectivity of the asymmetric hydrogenation.