191930-41-3Relevant academic research and scientific papers
Synthesis of unnatural α-amino esters using ethyl nitroacetate and condensation or cycloaddition reactions
Gagnot, Glwadys,Hervin, Vincent,Coutant, Eloi P.,Desmons, Sarah,Baatallah, Racha,Monnot, Victor,Janin, Yves L.
, p. 2846 - 2852 (2018/11/27)
We report here on the use of ethyl nitroacetate as a glycine template to produce α-amino esters. This started with a study of its condensation with various arylacetals to give ethyl 3-aryl-2-nitroacrylates followed by a reduction (NaBH4 and then zinc/HCl) into α-amino esters. The scope of this method was explored as well as an alternative with arylacylals instead. We also focused on various [2 + 3] cycloadditions, one leading to a spiroacetal, which led to the undesired ethyl 5-(benzamidomethyl)isoxazole-3-carboxylate. The addition of ethyl nitroacetate on a 5-methylene-4,5-dihydrooxazole using cerium(IV) ammonium nitrate was also explored and the synthesis of other oxazole-bearing α-amino esters was achieved using gold(I) chemistry.
IMIDAZOPYRAZINE DERIVATIVES, PROCESS FOR PREPARATION THEREOF, AND THEIR USES AS LUCIFERINS
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, (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.
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.
, 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.
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.
Iron-catalyzed oxidative C - H/C - H cross-coupling: An efficient route to α-quaternary α-amino acid derivatives
Li, Kaizhi,Tan, Guangying,Huang, Jingsheng,Song, Feijie,You, Jingsong
supporting information, p. 12942 - 12945 (2014/01/06)
Fully loaded: A coordinating activation strategy has been developed to furnish α-quaternary α-amino acids through the iron(III)-catalyzed oxidative functionalization of α-C(sp3) - H bonds of α-tertiary α-amino acid esters. The reaction exhibits a broad substrate scope for both α-amino acids and nucleophiles (Nu) as well as good functional-group tolerance (see scheme, DTBP=di-tert-butyl peroxide, DCE=1,2-dichloroethane). Copyright
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.
Synthesis of phenylalanine analogs
Chang, Meng-Yang,Lin, Chun-Yu,Sun, Pei-Pei
, p. 1061 - 1067 (2007/10/03)
A straight forward synthesis of phenylalanine analogs is described. Cerium ammonium nitrate (CAN) mediated addition of azide to cinnamicester, followed by reaction with sodium acetate aff orded the α-azidocinnamate in moderate yield. Hydrogenation of α-azidocinnamate, followed by BOC, CBZ or Fmoc protection gave phenylalanine analogs. A new approach for synthesizing racemic p-boronophenylalanine analog was also explored.
