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Michal Sienkiewicz - One of the best experts on this subject based on the ideXlab platform.
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solvent free synthesis of a secondary n benzhydrylamine as a Chiral Reagent for asymmetric deprotonation of bicyclic n benzylamino ketones
ChemInform, 2014Co-Authors: Aneta Nodzewska, Katarzyna Sidorowicz, Michal SienkiewiczAbstract:(R)-N-benzhydryl-1-phenylethylamine is utilized as Chiral auxiliary in asymmetric deprotonations of N-benzyl analogues of tropinone and granatanone.
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solvent free synthesis of a secondary n benzhydrylamine as a Chiral Reagent for asymmetric deprotonation of bicyclic n benzylamino ketones
Synthesis, 2014Co-Authors: Aneta Nodzewska, Katarzyna Sidorowicz, Michal SienkiewiczAbstract:Several Chiral secondary N -benzhydrylamines were synthesized in good yields (68–92%) without racemization by the direct alkylation of amines with benzhydryl chloride under solvent-free conditions. Using the solvent-free conditions ( R )- N -benzhydryl-1-phenylethylamine was obtained with the highest yield (92%), purified on ion-exchange resin, and converted to its hydrochloride salt. The resulting Chiral amine hydrochloride was transformed into lithium amide/lithium chloride mixture used in asymmetric deprotonations of N -benzyl analogues of tropinone and granatanone followed by aldol reactions giving products in high diastereomeric purities (up to 96%) and enantiomeric excesses of 77 to 96%.
Vadim A Soloshonok - One of the best experts on this subject based on the ideXlab platform.
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new Chiral Reagent for installation of pharmacophoric s or r 2 alkoxyphosphono 1 amino 2 2 difluoroethyl groups
ChemInform, 2016Co-Authors: Chen Xie, Lijun Zhang, Haibo Mei, Romana Pajkert, Yi Pan, Vadim A Soloshonok, Maksym Ponomarenko, Gerdvolker Roeschenthaler, Jianlin HanAbstract:The title Reagent (II) (<95% purity) is used without further purification due to its decomposition during distillation.
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new Chiral Reagent for installation of pharmacophoric s or r 2 alkoxyphosphono 1 amino 2 2 difluoroethyl groups
Chemistry: A European Journal, 2016Co-Authors: Chen Xie, Lijun Zhang, Haibo Mei, Romana Pajkert, Maxim Ponomarenko, Yi Pan, Gerdvolker Roschenthaler, Vadim A Soloshonok, Jianlin HanAbstract:A new Chiral Reagent has been developed for generalized installation of pharmacophoric (S)- or (R)-2-(alkoxyphosphono)-1-amino-2,2-difluoroethyl group into organic compounds. The original synthetic application of this new Reagent is exemplified by Friedel-Crafts reactions with indoles, which proceed efficiently with excellent diastereoselectivity to give enantiomerically pure products.
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Asymmetric Synthesis of α‐Amino Acids under Operationally Convenient Conditions
Advanced Synthesis & Catalysis, 2014Co-Authors: Manuel Jörres, José Luis Aceña, Xia Chen, Carina Merkens, Carsten Bolm, Hong Liu, Vadim A SoloshonokAbstract:A new multipurpose glycine equivalent for the general asymmetric synthesis of a-amino acids is introduced. The Chiral Reagent can be trans- formed to various amino acids by alkylations with alkyl halides as well as aldol and Michael addition reactions under operationally convenient reaction conditions at room temperature with virtually com- plete stereochemical control.
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Chemical approach for interconversion of (S)- and (R)-α-amino acids
Organic and Biomolecular Chemistry, 2013Co-Authors: Alexander E. Sorochinsky, Hisanori Ueki, José Luis Aceña, Trevor K. Ellis, Hiroki Moriwaki, Tatsunori Sato, Vadim A SoloshonokAbstract:Here we report a general method for the preparation of unnatural (R)-α-amino acids via complexation of α-(phenyl)ethylamine derived Chiral Reagent (S)-3 with various (S)-α-amino acids. The reactions proceed with synthetically useful chemical yields and thermodynamically controlled diastereoselectivity. Chiral Reagent (S)-3 can be conveniently recovered and reused without any loss of enantiomeric purity and reactivity.
Aneta Nodzewska - One of the best experts on this subject based on the ideXlab platform.
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solvent free synthesis of a secondary n benzhydrylamine as a Chiral Reagent for asymmetric deprotonation of bicyclic n benzylamino ketones
ChemInform, 2014Co-Authors: Aneta Nodzewska, Katarzyna Sidorowicz, Michal SienkiewiczAbstract:(R)-N-benzhydryl-1-phenylethylamine is utilized as Chiral auxiliary in asymmetric deprotonations of N-benzyl analogues of tropinone and granatanone.
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solvent free synthesis of a secondary n benzhydrylamine as a Chiral Reagent for asymmetric deprotonation of bicyclic n benzylamino ketones
Synthesis, 2014Co-Authors: Aneta Nodzewska, Katarzyna Sidorowicz, Michal SienkiewiczAbstract:Several Chiral secondary N -benzhydrylamines were synthesized in good yields (68–92%) without racemization by the direct alkylation of amines with benzhydryl chloride under solvent-free conditions. Using the solvent-free conditions ( R )- N -benzhydryl-1-phenylethylamine was obtained with the highest yield (92%), purified on ion-exchange resin, and converted to its hydrochloride salt. The resulting Chiral amine hydrochloride was transformed into lithium amide/lithium chloride mixture used in asymmetric deprotonations of N -benzyl analogues of tropinone and granatanone followed by aldol reactions giving products in high diastereomeric purities (up to 96%) and enantiomeric excesses of 77 to 96%.
Li Hai-lan - One of the best experts on this subject based on the ideXlab platform.
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Resolution of the isoprenalini enantiomers derivatized with fluorescent Chiral Reagents by reversed-phase high-performance liquid chromatography
The Chinese Journal of Modern Applied Pharmacy, 2005Co-Authors: Li Hai-lanAbstract:OBJECTIVE This paper describes a new method developed to separate isoprenalini enantiomers derivatized with fluorescent Chiral Reagent, DBD-PyNCS:R(-)-4-(N,N-Dimethylaminosulfonyl)-7-(3-iso-thiocyanatopyrrolidino)-2,1,3-benzoxadiazole, by reversed-phase high-performance liquid chromatography, on a Diamonsil~(TM)C_(18) column(150 mm×4.6 mm, i.d.,5μm),with a mobile phase of water-acetonitrile(65:35, v/v) and with a fluorescent detector : the excitation wavelength was 460nm and the emission wavelength was 550nm. The column was eluted at 40℃. Flow rate was 1mL/min. METHODS Fluorescent Chiral Reagent(36mmol/L,10μL) reacted with isoprenalini enantiomers(1mmol/L, 10μL),and then 10μL 20% pyridine acetonitrile solution was added.The resulting mixture was stirred for 1 min.And reacted at 65℃ for 35 min. and then a 10μL aliquot of the diastereomeric derivatives was injected directly into the chromatography. RESULTST The diastereomeric compounds were efficiently separated. The Rs value was 6.25; a = 1.20; L-isoprenalini k~(/ )=10.23;D-isoprenalini k~(/) =8.56. The retention time of D-isoprenalini and L-isoprenalini was 26.5min and 31.1min respectively. The linear range was 3.23 10~(-4)mol/L~2.63 10~(-3)mol /L (r=0.9997). The RSD. (L-isoprenalini concentration 1mmol/L) was 1.83%(n=7), the detection limits of isoprenalini enantiomers were 2.1 10~(-11 )mol /L(S/N=3).CONCLUSION The diastereomeric compounds were efficiently and rapidlly separated.
Toshimasa Toyooka - One of the best experts on this subject based on the ideXlab platform.
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towards the Chiral metabolomics liquid chromatography mass spectrometry based dl amino acid analysis after labeling with a new Chiral Reagent s 2 5 dioxopyrrolidin 1 yl 1 4 6 dimethoxy 1 3 5 triazin 2 yl pyrrolidine 2 carboxylate and the application
Analytica Chimica Acta, 2015Co-Authors: Toshiki Mochizuki, Takahiro Takayama, Kenichiro Todoroki, Koichi Inoue, Jun Zhe Min, Toshimasa ToyookaAbstract:Abstract A novel triazine-type Chiral derivatization Reagent, i.e., (S)-2,5-dioxopyrrolidin-1-yl-1-(4,6-dimethoxy-1,3,5-triazin-2-yl) pyrrolidine-2-carboxylate (DMT-(S)-Pro-OSu), was developed for the highly sensitive and selective detection of Chiral amines and amino acids by UPLC–MS/MS analysis. The enantiomers of amino acids were easily labeled with the Reagents at room temperature within 40 min in an alkaline medium containing triethylamine. The diastereomers derived from proteolytic amino acids, except serine, were well separated under isocratic elution conditions by reversed-phase chromatography using an ODS column (Rs = 1.2–9.0). dl -Serine was separated by use of an ADME column which has relatively higher polar surface than the conventional ODS column. The characteristic product ions, i.e., m/z 195.3 and m/z 209.3, were detected from all the diastereomers by the collision-induced dissociation of the protonated molecule. A highly sensitive detection on the amol–fmol level was obtained from the selected reaction monitoring (SRM) chromatogram. The Chiral amines (e.g., adrenaline and noradrenaline) labeled with DMT-(S)-Pro-OSu were also well separated and sensitively detected by the present procedure. The method using DMT-(S)-Pro-OSu was used for the determination of dl -amino acids in the human saliva from healthy volunteers. Various l -amino acids were identified in the saliva. Furthermore, d -alanine ( d -Ala) and d -proline ( d -Pro) were also detected in relatively high concentrations (>5%). The ratio was higher in male saliva than in female saliva. However, the difference in the ratio of d -Ala for one day was not very high and the effect of foods and beverage seemed to be negligible. Based on the results using l -Ala-d3, the d -Ala in saliva seemed to be produced due to the racemization with some enzymes such as racemase. The racemization reaction was reversible, i.e., d -Ala-d3 was also racemized to l -Ala-d3 in saliva. Thus, care should be taken during the analysis of dl -amino acids in saliva. The present method using DMT-(S)-Pro-OSu may be applicable for the determination of Chiral amine metabolomics, because the resulting derivatives produce the same product ions without relation to the compounds and show highly sensitive detection in the SRM mode of MS/MS. Consequently, DMT-(S)-Pro-OSu seems to be a useful Chiral derivatization Reagent for the determination of amines and amino acids in biological samples.