38964-54-4Relevant academic research and scientific papers
Rh(iii)-Catalyzed diastereoselective transfer hydrogenation: An efficient entry to key intermediates of HIV protease inhibitors
Chen, Gen-Qiang,Lang, Qi-Wei,Phansavath, Phannarath,Ratovelomanana-Vidal, Virginie,Wang, Fangyuan,Wu, Ting,Yin, Congcong,Zhang, Xumu,Zheng, Long-Sheng
supporting information, p. 3119 - 3122 (2020/03/23)
A highly efficient diastereoselective transfer hydrogenation of α-aminoalkyl α′-chloromethyl ketones catalyzed by a tethered rhodium complex was developed and successfully utilized in the synthesis of the key intermediates of HIV protease inhibitors. With the current Rh(iii) catalyst system, a series of chiral 3-amino-1-chloro-2-hydroxy-4-phenylbutanes were produced in excellent yields and diastereoselectivities (up to 99% yield, up to 99?:?1 dr). Both diastereomers of the desired products could be efficiently accessed by using the two enantiomers of the Rh(iii) catalyst.
Unnatural α-amino ethyl esters from diethyl malonate or ethyl β-bromo-α-hydroxyiminocarboxylate
Coutant, Eloi P.,Hervin, Vincent,Gagnot, Glwadys,Ford, Candice,Baatallah, Racha,Janin, Yves L.
supporting information, p. 2853 - 2860 (2018/11/26)
We have explored here the scope of the age-old diethyl malonate-based accesses to α-amino esters involving Knoevenagel condensations of diethyl malonate on aldehydes, reductions of the resulting alkylidenemalonates, the preparation of the corresponding α-hydroxyimino esters and their final reduction. This synthetic pathway turned out to be general although some unexpected limitations were encountered. The synthetic modifications of some of the intermediates - using Suzuki-Miyaura coupling or cycloadditions - before undertaking the oximation step - provided accesses to further α-amino esters. Moreover, other pathways to α-hydroxyimino esters were explored including an attempt to improve the cycloadditions between ethyl β-bromo-α-hydroxyiminocarboxylate and various alkylfuranes.
IMIDAZOPYRAZINE DERIVATIVES, PROCESS FOR PREPARATION THEREOF, AND THEIR USES AS LUCIFERINS
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Page/Page column 60; 62, (2018/11/22)
The present invention is in the field of bioluminescence in biology and/or medicine. In particular, the invention provides imidazopyrazine derivatives, processes for preparation thereof, and their uses as luciferins.
Pd-catalyzed directed ortho -C-H alkenylation of phenylalanine derivatives
García-Rubia, Alfonso,Laga, Eduardo,Cativiela, Carlos,Urriolabeitia, Esteban P.,Gómez-Arrayás, Ramón,Carretero, Juan C.
, p. 3321 - 3331 (2015/03/30)
A practical Pd-catalyzed ortho-olefination of enantioenriched N-(SO2Py)-protected aryl-alanine and norephedrine derivatives with electron-deficient alkenes has been developed using N-fluoro-2,4,6-trimethylpyridinium triflate as the terminal oxidant. The reaction occurs efficiently with excellent monosubstitution selectivity and without loss of enantiopurity. This cross-coupling proved to be broad in scope, tolerating a variety of steric and electronic changes to both coupling partners. Removal of the directing group under mild conditions provides access to optically active tetrahydroisoquinoline-3-carboxylic acid derivatives (Tics) with good diastereocontrol and with very small erosion of enantiomeric purity.
Fixation and recycling of nitrogen monoxide through carbonitrosation reactions
De Salas, Cristina,Heinrich, Markus R.
supporting information, p. 2982 - 2987 (2014/06/10)
The removal of nitrogen monoxide from gas streams through complexation to iron(ii) ions in aqueous dimethylsulfoxide can be combined with a new variant of the Meerwein arylation, which incorporates the previously complexed NO into organic compounds to give oximes as final products. The first step of this two-step process has been evaluated regarding the effectiveness of the NO absorption and the sensitivity of the aqueous iron(ii)-DMSO solution towards oxygen from air, in both cases in comparison with the known BioDeNOx process. The subsequent Meerwein arylation, which was designed with the intention to make use of nitrogen monoxide as the simplest nitrogen-centered radical scavenger, is shown to tolerate an exceptionally broad spectrum of substituents on the aromatic core of the diazonium salts including electron-donating as well as electron-withdrawing substituents. Under simple conditions the resulting oximes can be converted to racemic amino acid esters. This journal is the Partner Organisations 2014.
Resolution of N-protected amino acid esters using whole cells of Candida parapsilosis ATCC 7330
Stella, Selvaraj,Chadha, Anju
experimental part, p. 457 - 460 (2010/06/21)
Whole cells of Candida parapsilosis ATCC 7330 were used for the resolution of N-acetyl amino acid esters. Excellent enantioselectivities (E = 40 to >500) were achieved for the resolution of N-protected protein and non-protein amino acid esters giving good yields (28-50%) and high enantiomeric excesses (up to >99%) for both enantiomers.
Using ionic liquid [EMIM][CH3COO] as an enzyme-'friendly' co-solvent for resolution of amino acids
Zhao, Hua,Jackson, Lee,Song, Zhiyan,Olubajo, Olarongbe
, p. 2491 - 2498 (2007/10/03)
An ionic liquid (IL), 1-ethyl-3-methylimidazolium acetate [EMIM][CH3COO], was used in 0-4.0 M (~60% IL, v/v), as a nonvolatile organic medium for the enzymatic resolution of amino acids. When dl-phenylalanine methyl ester was studied as a model substrate, high enantiomeric excesses (ee) of l-amino acid were obtained in all ionic concentrations; however, lower yields were observed at high IL concentrations. This IL is more enzyme-'friendly' than the hydrophilic organic solvent acetonitrile and those ILs containing chaotropic anions (such as [EMIM][OTs]). Among three proteases and two lipases investigated, lyophilized Bacillus licheniformis protease exhibited the best enantioselectivity and activity. Highly enantioselective resolutions were also produced for several other amino acids in 2.0 M IL. Interestingly, high ee were also found in deuterium oxide (D2O) rather than in ordinary water, and a further enhancement was achieved with the co-existence of [EMIM][CH3COO]. The heavy water effect was explained in terms of protein stabilization by D2O. The secondary structural changes of enzyme in various media were interpreted by the second derivatives of FT-IR spectra.
Synthesis and antitumor activity of platinum(II) complexes containing substituted ethylenediamine ligands
Brunner, Henri,Hankofer, Peter,Holzinger, Ulrich,Treittinger, Barbara,Schoenenberger, Helmut
, p. 35 - 44 (2007/10/02)
The synthesis of substituted ethylenediamines, their reactions with K2PtCl4 to give the dichloroplatinum(II) complexes, and the exchange of the chloro ligands for other leaving groups are described.The new compounds have been tested as antitumor agents both in vitro using the hormone independent human mammary carcinoma cell line MDA-MB 231 as well as in vivo using the lymphocytic P388 leukemia of the CD2F1-mouse.In the P388 test, 53 of the 55 tested complexes fulfill the minimum activity of 125percent T/C required for a substance to be active.
Method of treating nausea and vomiting with certain substituted-phenylalkylamino (and aminoacid) derivatives and other serotonin depleting agents
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, (2008/06/13)
A method for the treatment of emesis in a mammal, which method comprises administering to said mammal an emesis inhibiting amount of a compound which depletes serotonin in the brain of mammals; among which are compounds having the formula: STR1 wherein, R is selected from hydrogen, loweralkyl, trifluoromethyl, carboxyl, or loweralkoxycarbonyl; R1 and R2 are hydrogen or loweralkyl; Z is trifluoromethyl or halogen; the optical isomers and pharmaceutically acceptable salts thereof; two of the preferred compounds of the invention are fenfluramine and norfenfluramine.
