56613-61-7Relevant articles and documents
Equilibrium of chiral extraction of 4-nitro-d,l-phenylalanine with BINAP metal complexes
Liu, Jia-Jia,Wu, Guo-Hui,Tang, Ke-Wen,Liu, Xiong,Zhang, Pan-Liang
, p. 80 - 89 (2014)
The enantioselective extraction of 4-nitro-phenylalanine (Nphy) was studied with metal-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) complexes as the chiral selector. The complex with palladium (BINAP-Pd) exhibits the highest selectivity out of the selectors studied, which is solubilised in the organic phase and preferentially extracts d-Nphy from the aqueous phase. Efficiency of extraction depends, often substantially, on a number of process variables, including types of organic solvents and metal precursors, concentration of ligand, pH, and temperature. A reactive extraction model was established to interpret the experimental data. The equilibrium formation constants and other important parameters required by the model were determined experimentally. The equilibrium formation constants were 6.73 and 1.93 for d-Nphy and l-Nphy. By way of modelling and experiment, an optimal extraction condition with pH of 7 and BINAP-Pd concentration of 1 mmol L-1 was obtained with enantioselectivity (α) of 3.37, which was close to the maximum of 3.48, and a performance factor (pf) of 0.195. The model was verified experimentally with excellent results.
Investigation of Taniaphos as a chiral selector in chiral extraction of amino acid enantiomers
Xiao, Wenjie,Chen, Shuhuan,Liu, Xiong,Ma, Yu
, p. 292 - 302 (2021/03/29)
Finding chiral selector with high stereoselectivity to a variety of amino acid enantiomers remains a challenge and warrants further research. In this work, Taniaphos, a chiral ligand with rotatable spatial configuration, was employed as a chiral extractant to enantioseparate various amino acid enantiomers. Phenylalanine (Phe), homophenylalanine (Hphe), 4-nitrophenylalanine (Nphe), and 3-chloro-phenylglycine (Cpheg) were used as substrates to evaluate the extraction efficiency. The results revealed that Taniaphos-Cu exhibited good abilities to enantioseparate Phe, Hphe, Nphe, and Cpheg with the highest separation factors (α) of 3.13, 2.10, 2.32, and 2.14, respectively. Taniaphos-Cu is more conducive to combine with D-amino acid in extraction. The influences of pH, Taniaphos-Cu, and concentration and extraction temperature on extraction were comprehensively evaluated. The highest performance factors (pf) for Phe, Hphe, Nphe, and Cpheg at optimal extraction conditions were 0.08892, 0.1250, 0.09621, and 0.08021, respectively. The recognition mechanism between Taniaphos-Cu and amino acid enantiomers was discussed. The coordination interaction between Taniaphos-Cu and -COO?, π-π interaction between Taniaphos-Cu and amino acid enantiomers are important acting forces in chiral extraction. The steric-hindrance between -NH2 and -OH lead to Taniaphos-Cu-D-Phe is more stable than Taniaphos-Cu-L-Phe. This work provided a chiral extractant that has good abilities to enantioseparate various amino acid enantiomers.
Bi-enzymatic Conversion of Cinnamic Acids to 2-Arylethylamines
Weise, Nicholas J.,Thapa, Prasansa,Ahmed, Syed T.,Heath, Rachel S.,Parmeggiani, Fabio,Turner, Nicholas J.,Flitsch, Sabine L.
, p. 995 - 998 (2020/01/21)
The conversion of carboxylic acids, such as acrylic acids, to amines is a transformation that remains challenging in synthetic organic chemistry. Despite the ubiquity of similar moieties in natural metabolic pathways, biocatalytic routes seem to have been overlooked for this purpose. Herein we present the conception and optimisation of a two-enzyme system, allowing the synthesis of β-phenylethylamine derivatives from readily-available ring-substituted cinnamic acids. After characterisation of both parts of the reaction in a two-step approach, a set of conditions allowing the one-pot biotransformation was optimised. This combination of a reversible deaminating and irreversible decarboxylating enzyme, both specific for the amino acid intermediate in tandem, represents a general method by which new strategies for the conversion of carboxylic acids to amines could be designed.