29622-19-3Relevant academic research and scientific papers
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.
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.
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.
