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Masatoshi Narita Masami Otsuka Susumu Kobayashi Masaji Ohno Yoji Umezawa Hajime Morishima Sei-ichi Saito Tomohisa Takita Hamao Umezawa 《Tetrahedron letters》1982,23(5):525-528
(2S,3S,4R)-4-Amino-3-hydroxy-2-methylpentanoic acid, a novel amino acid constituent of bleomycin, has been synthesized stereoselectively through aldol condensation of (R)-2-aminopropionaldehyde derivatives and E-vinyloxyboranes. 相似文献
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Nathan J. Line 《Tetrahedron letters》2019,60(20):1357-1358
A practical enantioselective synthesis of (3S, 4R)-3-hydroxypiperidine-4-carboxylic acid was accomplished via an unconventional Evans anti-aldol reaction followed by a one-pot azide reduction/reductive cyclization. 相似文献
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(2-Amino-3-cyano-4H-chromen-4-yl) phosphonic acid diethyl esters are prepared via a single-step multi-component reaction of structurally diverse salicylaldehydes with malononitrile and triethyl phosphite using a catalytic amount of potassium phosphate in ethanol at ambient temperature. Use of potassium phosphate as an inexpensive catalyst makes the protocol more economical. Mild reaction conditions, simple work-up procedure are the added advantages of the present method. 相似文献
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(2R,3R,4S)-4-Amino-7-guanidino-2,3-dihydroxyheptanoic acid (AGDHE), a common constituent of biologically active marine peptides, callipeltin A (1) and neamphamide A, was synthesized as its orthogonally protected derivative from l-glutamic acid in 15 steps. Guanidination by the Mitsunobu condition and osmium-catalyzed dihydroxylation of the corresponding Z-olefin were employed as the key steps. 相似文献
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The organocatalyzed enantioselective synthesis of biologically active 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carboxylate derivatives was achieved using bifunctional cinchona alkaloids as the catalysts. Using quinine thiourea as the catalyst, the tandem Michael addition-cyclization reaction between 1,3-cyclohexanediones and alkylidenecyanoacetate derivatives gives the desired products in high yields (up to 92%) and good ee values (up to 82%). 相似文献
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《Tetrahedron: Asymmetry》2006,17(15):2199-2202
2,4-Dioxo-4-phenylbutyric acid and 2-oxo-4-phenylbut-3-enoic acid are converted to the corresponding (S)-2-amino acids by recombinant Escherichia coli whole cells over-expressing aromatic transaminase from Enterobacter sp. BK2K-1 (AroATEs) in high yields (68–78%) and high enantiomeric purity (>99%) using l-aspartic acid as an amino donor. 相似文献
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(4S,5S)-4-Formyl-5-vinyl-2-oxazolidinone (4b), which is readily obtained via a zinc-silver-mediated reductive elimination of alpha-d-lyxofuranosyl phenyl sulfone (3b), is successfully converted to the naturally occurring, nonproteinogenic amino acid (2S,3R)-3-amino-2-hydroxydecanoic acid (2). Also in this study, a facile "oxazolidinone rearrangement" reaction is uncovered during the attempted formation of the (methylthio)thiocarbonate derivative of the oxazolidinone alcohol 7. 相似文献
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On the basis of the enaminone methodology, libraries of 3-amino-4H-quinolizin-4-ones, fused 3-amino-4H-pyrimidin-4-ones, and fused 3-amino-2H-pyran-2-ones were synthesized by the solid-phase and by the solution-phase parallel synthesis. The solution-phase approach turned out to be advantageous over the solid-phase approach. The solution-phase synthesis afforded, in most cases, analytically pure products in high yields, whereas the solid-phase approach gave products in poor yields and in low purity. 相似文献
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A convenient and efficient one-pot multi-component synthesis of novel polysubstituted 4-amino-2,3-dihydropyridines from carbonyl compounds, malononitrile and acetonitrile, using indium triflate is reported. Acetonitrile acts both as a solvent as well as a substrate. 相似文献
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《Tetrahedron: Asymmetry》2001,12(17):2421-2425
An efficient process for the synthesis of (R)-N-t-Boc-4-piperidinylglycine 8a, an unnatural amino acid, via enantioselective rhodium-catalyzed hydrogenation of the Cbz-enamide 5a is described. Subsequent deprotection of 8a affords unprotected (R)-4-piperidinylglycine 9 in good yield. 相似文献
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Carbocyclic ribofuranosylamine, a key intermediate for the synthesis of carbocyclic ribonucleosides, was synthesized by a facile route from the lactam, 2-azabicyclo[2.2.1]hept5-ene-3-one. 相似文献
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Stylianos HamilakisAthanase Tsolomitis 《Tetrahedron letters》2003,44(19):3821-3823
Malononitrile has been found to be acylated effectively using N-protected glycines by simultaneous activation of an amino acid carbonyl group and a malononitrile methylene group using carbonyl diimidazole (CDI). The corresponding aminoacetonitriles were isolated as enols and/or as their tautomeric forms, 2-amino-3-cyano-2-pyrrolin-4-ones. 相似文献
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The reaction of 2-amino-2-(trichloromethyl)tetrahydro-4-pyrone-5-spirocyclohexane with ethylenediamine afforded 6-amino-2,3-dihydro-4-pyrone-3-spirocyclohexane, whereas 2-amino-5,5-dimethyl-2-(trichloromethyl)tetrahydro-4-pyrone gave 2-(3-hydroxy-2,2-dimethylpropionylmethylene)imidazolidine in low yield. 相似文献
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The title compound has been prepared in optically pure form from (S)-glutamic acid. 相似文献
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Yu. M. Volovenko T. A. Volovnenko A. V. Dobrydnev 《Chemistry of Heterocyclic Compounds》2006,42(5):594-599
3-Cyano-3-hetaryl-2-oxopropyl thioacetates were obtained by the acylation of hetarylacetonitriles with acetylmercaptoacetyl
chloride. Their reaction with amines led to the formation of 2-amino-3-hetaryl-4(H)-oxothiophenes.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 680–685, May, 2006. 相似文献
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《Tetrahedron: Asymmetry》2005,16(7):1309-1319
Enantioselective hydrogenation of a series of (E)-α-substituted β-amidoacrylates using Rh(I)-catalysts with chiral phosphine ligands (BPE, DuPHOS) gives β2-amino acid derivatives with enantioselectivities of up to 67%. A β2,3-amino acid derivative was also synthesised with similar enantioselectivity (⩽65%) from the corresponding prochiral enamide. 相似文献
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[reaction: see text] A highly efficient enantioselective synthesis of (S)-(-)-acromelobic acid (1) was achieved via asymmetric hydrogenation of dehydroamino acid derivative (3) using (R,R)-[Rh(DIPAMP)(COD)]BF(4) catalyst followed by removal of protective groups in >98% ee and good over all yield. The key intermediate (3) was prepared from the commercially available citrazinic acid (4) in six steps. 相似文献
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S. D. Mikhno T. N. Polyanskaya V. M. Berezovskii 《Chemistry of Heterocyclic Compounds》1971,4(5):569-570
Methods of synthesis of 3-amino-4-ethoxycarbonylaminotetrahydrothiophene (VIII), and of other diamines, from 4-ethoxycarbonylaminotetrahydro-3-hydroxyiminothiophene (I), 2-benzylidene-4-ethoxycarbonylaminotetrahydro-3-hydroxyiminothiophene (III) and 4-ethoxycarbonylaminotetrahydro-3-hydroxythiophene (V) were investigated. Chlorination of V followed by the Gabriel synthesis gave VIII. 相似文献