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Colpaert F Mangelinckx S Rocchetti MT De Kimpe N 《Organic & biomolecular chemistry》2011,9(2):549-558
α-Methoxy- and α-ethoxyketones, as important intermediates in organic synthesis and flavor compounds in food chemistry, were synthesized by deprotonation of N-(1-alkoxy-2-propylidene)isopropylamine, prepared by condensation of the corresponding α-alkoxyacetone with isopropylamine, and subsequent reaction of the corresponding 1-azaallylic anions with alkyl halides to afford α'-alkylated, α-alkylated and α,α'-dialkylated ketimines. Hydrolysis of the imino function led to the desired substituted α-alkoxyketones. The ratio of α-, α'-, and α,α'-(di)alkylated compounds depended on the amount of base used and on the nature of the alkylating reagent. 相似文献
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K. Boukallaba A. Elachqar A. El Hallaoui A. Alami S. El Hajji B. Labriti 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):819-823
α-heterocyclic α-aminophosphonates were obtained in good yields by N-of several nitrogen heterocycles with α-azido-α-aminophosphonate 1. 1 相似文献
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Vorobyeva DV Karimova NM Odinets IL Röschenthaler GV Osipov SN 《Organic & biomolecular chemistry》2011,9(21):7335-7342
A convenient strategy for the synthesis of isoxazole-containing α-CF(3)-substituted α-aminocarboxylates and α-aminophosphonates have been developed. The method is based on copper-catalyzed 1,3-dipolar cycloaddition of different aromatic nitrile oxides to functionalized acetylenes. 相似文献
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A series of new α-hydroxyphosphonate (5–14) have been synthesized in high yields by reaction of β-chloro-α,β-unsaturated aldehydes (1–4) and trialkyl phosphite in the presence of chlorotrimethylsilane at room temperature under solvent-free conditions. In addition, compounds (5–14) were reacted with acetic anhydride in DBU to give the new α-acetoxyphosphonate derivatives (15–23). All these phosphonates (5–23) were obtained as mixtures of two (E and Z) isomers and fully characterized by multinuclear (1H, 13C, and 31P) NMR, IR spectroscopy and HRMS. 相似文献
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Seyed Mohammad Vahdat Robabeh Baharfar Akbar Heydari Samad Khaksar 《Tetrahedron letters》2008,49(46):6501-6504
A new and highly flexible procedure is described for the synthesis of α-amino- and α-hydroxy phosphonates. In the presence of a catalytic amount of oxalic acid (10 mol %), trimethyl phosphite reacts with aldehydes or imines (generated in situ from an aldehyde and an amine) to yield the corresponding coupled products in good yield. 相似文献
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El Houssine Mabrouk Elachqar Abdelrhani El Hallaoui Abdelilah Alami Anouar El Hajji Soumia Martinez Jean Rolland Vallery 《Arabian Journal of Chemistry》2013,6(1):93-96
New racemic α-aminoester and α,α-diaminoesters derivatives were synthesized by nucleophilic substitution of methyl α-azido glycinate N-benzoylated with 3-amino-1,2,4-triazole, 2-tetrahydrofuran-2-ylmethan-amine and 2-methyl quinolin-4-amine. 相似文献
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Long Chen Yun-Xiang Zou Xin-Yue Fang Xu Yin 《Phosphorus, sulfur, and silicon and the related elements》2018,193(3):168-177
We report a convenient catalytic Friedel-Crafts arylation of α-aryl α-hydroxyphosphonates with various (hetero)aromatic compounds. HOTf (trifluoromethanesulfonic acid) is identified to be the best Brønsted acid catalyst, and the desired α-diarylmethylphosphonates were obtained in up to 41–95% yield. 相似文献
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V. S. Renzik V. D. Akamsin I. V. Galyametdinova S. G. Fattakhov B. E. Ivanov 《Russian Chemical Bulletin》1999,48(5):979-983
Dialkyl β-(2-aroxyethylamino)ethylphosphonates,N-[β-(2-methoxyphenoxy)ethyl]-N′-[β-(diethoxyphosphoryl)ethyl]-α,ω-diaminoalkanes, and diethyl β-(N-arylpiperazino)ethyl-phosphonates were synthesized by the reactions of dialkyl vinylphosphonates with β-aroxyethylamines,N-[β-(2-methoxyphenoxy)ethyl]-α,ω-diaminoalkanes, andN-aryl-piperazines, respectively. The compounds synthesized exhibit hypotensive and α-adrenolytic activities.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 987–991, May 1999. 相似文献
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Felix Krämer Dr. Michael Radius Dr. Alexander Hinz Melina E. A. Dilanas Prof. Dr. Frank Breher 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(1):e202103974
The synthesis and full characterization of α-silylated (α-SiCPs; 1 – 7 ) and α-germylated (α-GeCPs; 11 – 13 ) phosphorus ylides bearing one chloride substituent R3PC(R1)E(Cl)R22 (R=Ph; R1=Me, Et, Ph; R2=Me, Et, iPr, Mes; E=Si, Ge) is presented. The molecular structures were determined by X-ray diffraction studies. The title compounds were applied in halide abstraction studies in order to access cationic species. The reaction of Ph3PC(Me)Si(Cl)Me2 ( 1 ) with Na[B(C6F5)4] furnished the dimeric phosphonium-like dication [Ph3PC(Me)SiMe2]2[B(C6F5)4]2 ( 8 ). The highly reactive, mesityl- or iPr-substituted cationic species [Ph3PC(Me)SiMes2][B(C6F5)4] ( 9 ) and [Ph3PC(Et)SiiPr2][B(C6F5)4] ( 10 ) could be characterized by NMR spectroscopy. Carrying out the halide abstraction reaction in the sterically demanding ether iPr2O afforded the protonated α-SiCP [Ph3PCH(Et)Si(Cl)iPr2][B(C6F5)4] ( 6 dec ) by sodium-mediated basic ether decomposition, whereas successfully synthesized [Ph3PC(Et)SiiPr2][B(C6F5)4] ( 10 ) readily cleaves the F−C bond in fluorobenzene. Thus, the ambiphilic character of α-SiCPs is clearly demonstrated. The less reactive germanium analogue [Ph3PC(Me)GeMes2][B{3,5-(CF3)2C6H3}4] ( 14 ) was obtained by treating 11 with Na[B{3,5-(CF3)2C6H3}4] and fully characterized including by X-ray diffraction analysis. Structural parameters indicate a strong CYlide−Ge interaction with high double bond character, and consequently the C−E (E=Si, Ge) bonds in 9 , 10 and 14 were analyzed with NBO and AIM methods. 相似文献
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Demizu Y Doi M Kurihara M Okuda H Nagano M Suemune H Tanaka M 《Organic & biomolecular chemistry》2011,9(9):3303-3312
Four types of α,α-disubstituted amino acids {i.e., α-aminoisobutyric acid (Aib), 1-aminocyclopentanecarboxylic acid (Ac(5)c), (3S,4S)-1-amino-(3,4-dimethoxy)cyclopentanecarboxylic acid [(S,S)-Ac(5)c(dOM)] and its enantiomer (R,R)-Ac(5)c(dOM)} were introduced into l-leucine-based hexapeptides and nonapeptides. The dominant conformations of eight peptides: Cbz-(L-Leu-L-Leu-dAA)(2)-OMe [dAA = 1: Aib; 2: Ac(5)c; 3: (S,S)-Ac(5)c(dOM); 4: (R,R)-Ac(5)c(dOM)] and Boc-(L-Leu-L-Leu-dAA)(3)-OMe [dAA = 5: Aib; 6: Ac(5)c; 7: (S,S)-Ac(5)c(dOM); 8: (R,R)-Ac(5)c(dOM)], were investigated by IR, CD spectra and X-ray crystallographic analysis. The CD spectra revealed that Aib hexapeptide 1 and Ac(5)c hexapeptide 2 formed right-handed (P) 3(10)-helices, while Ac(5)c(dOM) hexapeptides 3 and 4 formed a mixture of (P) 3(10)- and α-helices. The Aib nonapeptide 5 formed a (P) 3(10)-helix, the Ac(5)c nonapeptide 6 formed a mixture of (P) 3(10)- and α-helices, and the Ac(5)c(dOM) nonapeptides 7 and 8 formed (P) α-helices. X-Ray crystallographic analysis revealed that the Aib hexapeptide 1 formed a (P) 3(10)-helix, while (S,S)-Ac(5)c(dOM) hexapeptide 3 formed a (P) α-helix. In addition, the Ac(5)c nonapeptide 6 and (R,R)-Ac(5)c(dOM) nonapeptide 8 formed (P) α-helices. The Aib and achiral Ac(5)c residues have the propensity to form 3(10)-helices in short peptides, whereas the chiral Ac(5)c(dOM) residues have a penchant for forming α-helices. 相似文献
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The diffusion coefficients of nitrogen were measured in polycrystalline h.c.p. α-Zr and α-Hf. The nitrogen-implanted zirconium and hafnium samples used for the measurements were annealed at temperatures of 500–700°C and 550–900°C respectively. The nitrogen profiles were probed using the broadening of the (p, αγ) resonance. Doses of 1.8 × 1020 and 1.2 × 1021 ions m−2 were used for the 40 keV 15N implants, but no differences in the diffusivity were observed. Values of 2.50 eV and 2.51 eV for the activation energy and 0.56 cm2 s−1 and 0.024 cm2 s−1 for the frequency factor were obtained for α-Zr and α-Hf respectively. 相似文献
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《Tetrahedron letters》1986,27(33):3823-3826
α-Oxo ketene dithioacetals can be converted into α-pyrones in a three step process involving 1,2-nucleophilic addition of ester or ketone enolate anions, acid promoted rearrangement, and subsequent enol lactonization. Utilization of ester enolates affords 6-alkylthio α-pyrones while ketone enolates give 3-alkyl substituted α-pyrones. 相似文献
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The Hiyama couplings of both α-silylenoates and α-silylenamides are described. These sensitive substrate classes require particularly specific conditions, employing both appropriate silicon-based species and a silver additive to realize high yields of the coupling products. Regioselective platinum-catalyzed hydrosilylations provide a direct and convenient entry into these stereodefined trisubstituted alkenes. 相似文献
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V. S. Reznik V. D. Akamsin I. V. Galyametdinova A. V. Chernova R. R. Shagidullin 《Russian Chemical Bulletin》2000,49(3):490-494
A method for the synthesis of hypotensive alkyl(phenyl)[ω-(N-phenylpiperazino)alkyl]-phosphine oxides by reacting alkyl(ω-haloalkyl)phenylphosphine oxides withN-phenylpiperazine was elaborated. Phenyl[γ-(N-phenylpiperazino)propyl]propylphosphine oxide reacts with alkyl halides to give [γ-(N-alkyl-N′-phenylpiperazinio)propyl]phenyl(propyl)oxophosphine halides.
For Part 1 see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 488–492, March, 2000. 相似文献
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V. S. Reznik Ya. A. Levin V. D. Akamsin I. V. Galyametdinova R. I. Pyrkin 《Russian Chemical Bulletin》2000,49(3):495-498
Primary alkylamines, β-aryloxyethylamines, orN-[β-(2-methoxyphenoxy)ethyl]-α,ω-diaminoalkanes react with alkyl divinyl phosphinates or phenyl(divinyl)phosphine oxide to give the corresponding 4-alkoxy(4-phenyl)-1-alkyl-4-oxo-1,4-azaphosphorinanes. Reactions of the latter with mono- or dihaloalkanes afford 4-phosphapiperidinium halides. 1,4-Azaphosphorinanes containing a β-aryloxyethyl fragment exhibit hypotensive activity. 相似文献