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121.
A facile synthetic route to the new 2-TIPS-oxazol-5-ylboronic acid pinacol ester was described herein. Its reactivity toward Suzuki cross-coupling reaction was studied to provide various 5-(het)aryloxazoles. A wide range of functions on the aryl moiety are tolerated. 相似文献
122.
Bureau R Daveu C Lemaître S Dauphin F Landelle H Lancelot JC Rault S 《Journal of chemical information and computer sciences》2002,42(4):962-967
A definition of a pharmacophore for the 5-HT4 antagonist was carried out by considering a three-dimensional model which correlates the chemical structures of series of antagonists with their biological affinities. A molecular design is described by analyzing the differences between two 3D serotonin pharmacophores. This successful structural modification demonstrates the efficiency of this approach to design new serotonin ligands. 相似文献
123.
We performed low temperature shot noise measurements in superconductor (TiN) strongly disordered normal metal (heavily doped Si) weakly transparent junctions. We show that the conductance has a maximum due to coherent multiple Andreev reflections at low energy and that the shot noise is then twice the Poisson noise (S = 4eI). When the subgap conductance reaches its minimum at finite voltage the shot noise changes to the normal value (S = 2eI) due to a large quasiparticle contribution. 相似文献
124.
125.
Pasquarello C Sanchez JC Hochstrasser DF Corthals GL 《Rapid communications in mass spectrometry : RCM》2004,18(1):117-127
The synthesis and application of two new alkylating reagents, N-tert-butyl-2-iodoacetamide (N-t-butyliodoacetamide) and 2-iodo-N-phenylacetamide (iodoacetanilide), are described. N-t-Butyliodoacetamide and iodoacetanilide were synthesised to purity in their d(0)-light and in their respective d(9)- and d(5)-heavy forms. The newly synthesised reagents are covalently bound to peptides containing cysteines via an alkylation reaction. The mass differences of 5 and 9 Da avoid possible problems of overlapping isotope distribution. For each alkylated cysteine a peptide mass increases, respectively, by a multiple of 113 and 133 Da for the d(0)-light form of N-t-butyliodoacetamide and iodoacetanilide. These reagents can therefore replace common alkylating reagents in existing proteomics-based applications. Alkylated peptides increase in mass in the same mass range as amino acids and remain suitable for tandem mass spectrometry (MS/MS) data acquisition and analysis. The compounds are simple to use and derivatisation is based on widely applied alkylating procedures. Preliminary results show that these reagents can be applied for both protein quantitation and identification by peptide mass finger printing and/or MS/MS techniques. Using these chemicals and the suggested workflow enables the quantitative analysis of the whole protein sample and realises access to peptides that may contain potential post-translational modifications. Other approaches that incorporate a matrix-assisted laser desorption/ionisation (MALDI) interface prior to MS can take advantage of these chemicals, such as the molecular scanner. 相似文献
126.
Abdolali Basiri Andreas Enge Jean-Charles Faugè re Nicolas Gü rel. 《Mathematics of Computation》2005,74(249):389-410
We present two algorithms for the arithmetic of cubic curves with a totally ramified prime at infinity. The first algorithm, inspired by Cantor's reduction for hyperelliptic curves, is easily implemented with a few lines of code, making use of a polynomial arithmetic package. We prove explicit reducedness criteria for superelliptic curves of genus 3 and 4, which show the correctness of the algorithm. The second approach, quite general in nature and applicable to further classes of curves, uses the FGLM algorithm for switching between Gröbner bases for different orderings. Carrying out the computations symbolically, we obtain explicit reduction formulae in terms of the input data.
127.
[reaction: see text] The synthesis of alpha-arylated beta-substituted cyclopropylphosphonates was efficiently achieved by electroreduction of diethyl alpha,alpha-dichlorobenzylphosphonate in the presence of Michael acceptors in a one-compartment cell equipped with a magnesium sacrificial anode. 相似文献
128.
Yamien Effi Sylvain Rault Jean-Charles Lancelot Max Robba 《Journal of heterocyclic chemistry》1987,24(2):431-435
5-Aminopyrrolo[1,2-a]thieno[2-3-3]pyrazine derivatives were obtained by intramolecular cyclisation of N3(1-pyrrolyl)-2-thienylurea derivaties. Synthesis of these latter compounds was achieved from 2-(1-pyrrolyl)-3-thenoylazide via a curtius rearrangement. The H nmr spectra are discussed. 相似文献
129.
Jean-Marie Gazengel Jean-Charles Lancelot Sylvain Rault Max Robba 《Journal of heterocyclic chemistry》1989,26(4):1135-1139
The synthesis of dihydropyrimidinocarbazoles 12,15 and 18 was achieved by cyclization of tetrahydrocarbazolones with triformamidomethane. The oxidation with potassium permanaganate of dihydropyrimidinocarbazoles gave the pyrimidinocarbazoles 13,16 and 19. The application of the Sandemeyer reaction to amiononitrocarbazoles gave cyanonitrocarbazoles which could be reduced to aminocyanocarbazoles 1 and 7. Intramolecular cyclization of the carbazoles 1 and 7 afforded 3,4-dilhydro-4-oxo-6H-pyrimidino[5,4-b]carbazole 2 and 1,2-dighydro-1-oxo-6H-pyrimidino[5,4-b]carbazole 10 was obtained by cyclization of quinazolinyl hydrazone 9 with hydrochloric acid and acetic acid. The structure of the derivatives was determined by 1H-nmr and the Overhauser effect. 相似文献
130.