67337-75-1

Upstream product

• 114592-77-7 (2S,6R)-2-Ethoxy-2,6-dimethyl-1,3-dioxan-4-on 
• 100-46-9 benzylamine 
• 91246-78-5 3-benzylaminobutyric acid 
• 72687-57-1 β-benzylamino-butyronitrile 
• 507444-65-7 methyl 3-(benzylamino)butanoate 

Downstream Products

• 112979-62-1 3-benzylamino-butyric acid methyl ester 

Relevant academic research and scientific papers

Process Optimisation Studies and Aminonitrile Substrate Evaluation of Rhodococcus erythropolis SET1, A Nitrile Hydrolyzing Bacterium

A comprehensive series of optimization studies including pH, solvent and temperature were completed on the nitrile hydrolyzing Rhodococcus erythropolis bacterium SET1 with the substrate 3-hydroxybutyronitrile. These identified temperature of 25 °C and pH of 7 as the best conditions to retain enantioselectivity and activity. The effect of the addition of organic solvents to the biotransformation mixture was also determined. The results of the study suggested that SET1 is suitable for use in selected organo-aqueous media at specific ratios only. The functional group tolerance of the isolate with unprotected and protected β-aminonitriles, structural analogues of β-hydroxynitriles was also investigated with disappointingly poor isolated yields and selectivity obtained. The isolate was further evaluated with the α- aminonitrile phenylglycinonitrile generating acid in excellent yield and ee (>99 % (S) – isomer and 50 % yield). A series of pH studies with this substrate indicated pH 7 to be the optimum pH to avoid product and substrate degradation.

Mechanochemical enzymatic resolution of N-benzylated-β3-amino esters

The use of mechanochemistry to carry out enantioselective reactions has been explored in the last ten years with excellent results. Several chiral organocatalysts and even enzymes have proved to be resistant to milling conditions, which allows for rather efficient enantioselective transformations under ball-milling conditions. The present article reports the first example of a liquid-assisted grinding (LAG) mechanochemical enzymatic resolution of racemic β3-amino esters employing Candida antarctica lipase B (CALB) to afford highly valuable enantioenriched N-benzylated-β3-amino acids in good yields. Furthermore the present protocol is readily scalable.

Nitrile biotransformations for the synthesis of highly enantioenriched β-hydroxy and β-amino acid and amide derivatives: A general and simple but powerful and efficient benzyl protection strategy to increase enantioselectivity of the amidase

(Chemical Equation Presented) Biotransformations of a number of racemic β-hydroxy and β-amino nitrile derivatives were studied using Rhodococcus erythropolis AJ270, the nitrile hydratase and amidase-containing microbial whole cell catalyst, under very mild conditions. The overall enantioselectivity of nitrile biotransformations was governed predominantly by the amidase whose enantioselectivity was switched on remarkably by an O- and a N-benzyl protection group of the substrates. While biotransformations of β-hydroxy and β-amino alkanenitriles gave low yields of amide and acid products of very low enantiomeric purity, introduction of a simple benzyl protection group on the β-hydroxy and β-amino of nitrile substrates led to the formation of highly enantioenriched β-benzyloxy and β-benzylamino amides and acids in almost quantitative yield. The easy protection and deprotection operations, high chemical yield, and excellent enantioselectivity render the nitrile biotransformation a useful protocol in the synthesis of enantiopure β-hydroxy and β-amino acids.

Efficient resolution of racemic N-benzyl β3-amino acids by iterative liquid-liquid extraction with a chiral (salen)cobalt(iii) complex as enantioselective selector

The efficient (up to 93% ee) resolution of racemic N-benzyl β3-amino acids has been achieved by an iterative (two cycle) liquid-liquid extraction process using a lipophilic chiral (salen)cobalt(iii) complex [CoIII(1)(OAc)]. As a result of the resolution by extraction, one enantiomer of the N-benzyl β3-amino acid predominated in the aqueous phase, while the other enantiomer was driven into the organic phase by complexation to cobalt. The complexed amino acid was then quantitatively released into an aqueous phase, by a reductive (CoIII → Co II) counter-extraction using l-ascorbic acid. The reductive cleavage allowed for the recovery of the cobalt(ii) selector in up to 90% yield (easily re-oxidable to CoIII with air/AcOH). The Royal Society of Chemistry.

Evaluating β-amino acids as enantioselective organocatalysts of the Hajos-Parrish-Eder-Sauer-Wiechert reaction

A systematic study of the effect of substitution within the β-amino acid framework indicates that both β2- and β3- amino acids catalyse the Hajos-Parrish-Eder-Sauer-Wiechert reaction with poor to reasonable levels of enantioselectivity. These results led to the evaluation of the conformationally constrained β-amino acid (1R,2S)-cispentacin, which catalyses the Hajos-Parrish-Eder-Sauer-Wiechert reaction with comparable or higher levels of enantioselectivity to l-proline. The Royal Society of Chemistry.

Herstellung enantiomerenreiner Derivate von 3-Amino- und 3-Mercaptobuttersaeure durch SN2-Ringoeffnung des β-Lactons und eines 1,3-Dioxanons aus der 3-Hydroxybuttersaeure

From (S)-4-methyloxetan-2-one (1), the β-butyrolactone readily available from the biopolyner (R)-polyhydroxybutyrate (PHB) and various C,N,O and S nucleophiles, the following compounds are prepared: (S)-2-hydroxy-4-octanone (3), (R)-3-aminobutanoic acid (7) and its benzyl derivative 5, (R)-3-azidobutanoic acid (6), (R)-3-mercaptobutanoic acid (10), (R)-3-(phenylthio)butanoic acid (8) and its sulfoxide 9.The (6R)-2,6-dimethyl-2-ethoxy-1,3-dioxan-4-one (4) from (R)-3-hydroxybutanoic acid undergoes SN2 ring opening with benzylamine to give the N-benzyl derivative (ent-5) of (S)-3-aminobutanoic acid in 30-40percent yield.