共查询到20条相似文献,搜索用时 15 毫秒
1.
1-Alkoxy-1-arylmethanephosphonates (3) can be prepared by the reaction of arylaldehyde acetal (2) and diethyl trimethylsilyl phosphite (1) in the presence of stannic chloride under mild conditions. 相似文献
2.
Titanium(IV) chloride-catalyzed addition of diethyl trimethylsilyl phosphite to β-nitrostyrenes affords α-phosphoryl nitronates which, on treatment with low valent titanium in situ generated from titanium(IV) and zinc, are smoothly converted to 1-aryl-1-cyanomethanephosphonates in good yields. 相似文献
3.
Organometallic reagents readily added to diethyl l-(trimethylsilyl) vinylphosphonate 1 by virtue of the polarizing silyl group. Quenching with acetic acid, methyl iodide, and carbonyl compounds gave synthetically useful diethyl alkylphosphonates 6 and diethyl alkenylphosphonates 8 respectively. 相似文献
4.
(1-萘甲基)四氢糠基丙二酸二乙酯的新法合成 总被引:2,自引:1,他引:1
(1-萘甲基)四氢糠基丙二酸二乙酯(Ⅴ)是合成萘呋胺酯草酸盐的重要前体,而萘呋胺酯草酸盐作为一种新型周围血管扩张剂,正受到越来越多的重视[1,2].(1-萘甲基)四氢糠基丙二酸二乙酯(Ⅴ)的原有合成方法[3]产率低,且反应时间长.本文改进了(Ⅴ)的原... 相似文献
5.
1mrnODUCTIoNThederivativesofa-aminophosphonicacidhavebeenwidelystudiedduetotheinterestintheirvariousbiologicalactivitiestl)-Forthepurposeofsearchingfornewkindsofherbicides,aseriesofdiethyl1-(P-toluenesulfonamido)-(substituted)phenylmethylphosphonates1havebeensynthesizedbyathree-comPonentreaction'ofHtoluenesulfonamide,a(substituted)benzaldehydeanddiethylphosphite(2).Howev-er,thelHNMRsPectraofalltheproductsshowedthatthetwoethoxygroupsintheirstructuresaremagneticallynonequivalent.Inordertoe… 相似文献
6.
The 1-formylalkanephosphonates were obtained by the ozonolysis of the corresponding 1-alkylated allylphosphonates, which had been previously prepared by treatment with n-BuLi, followed by addition of alkyl halides. 相似文献
7.
Prosyanik A. V. Fedoseenko D. V. Markov V. I. 《Chemistry of Heterocyclic Compounds》1982,18(11):1216-1216
Chemistry of Heterocyclic Compounds - 相似文献
8.
AScopeStudyofCondensationof1,3-DiketoneswithDiethylAcetonedicarboxylateZHONGZhen-qi,TANGHui-tong,ZHANGPang(DepartmentofChemis... 相似文献
9.
High quality poly(5-cyanoindole) (P5CI) films were electrosynthesized by direct anodic oxidation of 5-cyanoindole on stainless steel sheet in the mixed electrolytes of boron trifluoride diethyl etherate (BFEE) and diethyl ether (EE) (by volume 1:1) + 0,05 mol L^-1 Bu4NBF4. The film formed can be peeled off the electrode into freestanding films, The addition of EE into BFEE can improve the solubility of monomer. P5CI films obtained from this medium showed excellent electrochemical behavior with conductivity of 10^-2 S cm^-1, Structural studies showed that the polymerization of 5-cyanoindole occurred at the 2,3 position. As-formed P5CI films were thoroughly soluble in strong polar organic solvent dimethyl sulfoxide (DMSO) while partly soluble in tetrahydrofuran (THF) or acetone. Fluorescence spectral studies indicated that P5CI was a good blue-ight emitter. 相似文献
10.
Nuwandi M. Ariyasingha Dr. Baptiste Joalland Hassan R. Younes Dr. Oleg G. Salnikov Dr. Nikita V. Chukanov Dr. Kirill V. Kovtunov Dr. Larisa M. Kovtunova Prof. Valerii I. Bukhtiyarov Prof. Igor V. Koptyug Prof. Juri G. Gelovani Prof. Eduard Y. Chekmenev 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(60):13621-13626
The growing interest in magnetic resonance imaging (MRI) for assessing regional lung function relies on the use of nuclear spin hyperpolarized gas as a contrast agent. The long gas-phase lifetimes of hyperpolarized 129Xe make this inhalable contrast agent acceptable for clinical research today despite limitations such as high cost, low throughput of production and challenges of 129Xe imaging on clinical MRI scanners, which are normally equipped with proton detection only. We report on low-cost and high-throughput preparation of proton-hyperpolarized diethyl ether, which can be potentially employed for pulmonary imaging with a nontoxic, simple, and sensitive overall strategy using proton detection commonly available on all clinical MRI scanners. Diethyl ether is hyperpolarized by pairwise parahydrogen addition to vinyl ethyl ether and characterized by 1H NMR spectroscopy. Proton polarization levels exceeding 8 % are achieved at near complete chemical conversion within seconds, causing the activation of radio amplification by stimulated emission radiation (RASER) throughout detection. Although gas-phase T1 relaxation of hyperpolarized diethyl ether (at partial pressure of 0.5 bar) is very efficient, with T1 of ca. 1.2 second, we demonstrate that, at low magnetic fields, the use of long-lived singlet states created via pairwise parahydrogen addition extends the relaxation decay by approximately threefold, paving the way to bioimaging applications and beyond. 相似文献
11.
《Journal of Inorganic and Nuclear Chemistry》1978,40(5):769-772
Complexes of diethyl acetylphosphonate(deap) with 3d metal perchlorates were synthesized and characterized by means of IR and electronic spectral, magnetic susceptibility and conductance studies. The final solid products obtained during interaction of deap and metal salt in triethyl orthoformate are of the general type [M(deap)3](ClO4)n·H2O (MMn2+, Fe2+, Fe2+, Co2+, Ni2+, Zn2+; n = 2 o 3), involving a tris-chelate complex cation, in which deap coordinates as a bidentate ligand through the PO and CO oxygens; these metal chelates contain also exclusively ionic perchlorate and lattice water. In some cases (MMn2+, Co2+) the preceding chelates are precipitated directly from the ligand-salt reaction mixture in triethyl orthoformate. In other cases (MFe2+, Fe3+, Ni2+, Zn2+), however, viscous oily precipitates of the type [M(deap)3(OH2)3](ClO4)n·xH2O (n = 2 or 3; x = 1–3) are initially obtained. These oily products, in which deap functions as unidentate, coordinating only through the PO oxygen, are then converted to solid [M(deap)3](ClO4)n·H2O tris-chelates, by treatment with additional triethyl orthoformate (and diethyl ether). The competition between deap and aqua ligands for the inner coordination sphere of the metal ion is due to the fact that deap is a relatively weak ligand, giving rise to a ligand field of about equal strength to that generated by the aqua group. 相似文献
12.
LI ZaiGuoHUANG RunQiuCHENG JunRan 《结构化学》1999,18(4)
1INTRODUCTIONα Aminophosphonicacids,bioisosteresofnaturalaminoacids,haveatractedmuchatentionbecausetheyshowwidebiologicalacti... 相似文献
13.
Chester M. Mikulski William Henry Louis L. Pytlewski Nicholas M. Karayannis 《Transition Metal Chemistry》1977,2(1):135-140
Summary Complexes (2 : 1) of diethyl benzoylphosphonate (debp) with 3d metal perchlorates were synthesized and characterized by means of i.r. and electronic spectral, magnetic susceptibility and conductance measurements. In new complexes of the types [M(debp)2(OClO3)(OH2)](ClO4) (M = Fe, Co, Zn) and [Fe(debp)2(OClO3)(OH2)](ClO4)2, both debp ligands function as bidentate chelating agents, coordinating through the P=O and C=O oxygens. In contrast, in the manganese(II) and nickel(II) complexes, which are of the [M(debp)2(OClO3)(OH2)2](ClO4) type, one debp acts as a bidentate chelating ligand, while the second debp is unidentate, coordinating only through the P=O oxygen. Hexacoordination in the new cationic complexes is completed by coordination of aqua and unidentate perchlorato ligands, which are in competition for sites in the inner coordination sphere of the central metal ion with the weak debp ligand. On the other hand, debp, owing to its bulkiness, and especially the presence of the benzoyl substituent, introduces sufficiently severe steric hindrance during coordination. As a result of this, the formation of [M(debp)3]n+ tris-chelate cationic complexes with the 3 d metal ions under study does not seem to be possible. 相似文献
14.
15.
以4,6-二甲基-2-甲氧基-1,3-苯二甲酸二乙酯为原料,经Micheal加成、环化、溴化、消除等5步反应,合成新型的多取代2,7-萘二甲酸二乙酯.该合成路线步骤少,收率高,反应条件温和.产物中的4个新化合物的结构均经元素分析、核磁共振、红外光谱和质谱确证. 相似文献
16.
Diethyl Fluoronitromethylphosphonate: Synthesis and Application in Nucleophilic Fluoroalkyl Additions
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Stanislav Opekar Dr. Radek Pohl Pavel Beran Dr. Lubomír Rulíšek Dr. Petr Beier 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(5):1453-1458
Diethyl fluoronitromethylphosphonate ( 3 ), a previously unknown compound, was synthesized by electrophilic fluorination of diethyl nitromethylphosphonate with Selectfluor. Base‐induced decomposition of 3 was studied by NMR spectroscopy, which identified diethyl fluorophosphate and fluoronitromethane as the main decomposition products. C?H acidities [pKa values in dimethyl sulfoxide (DMSO)] of 3 , 1‐fluoro‐1‐phenylsulfonylmethanephosphonate ( 1 ; McCarthy’s reagent), tetraethyl fluoromethylenebisphosphonate ( 2 ), and some nonfluorinated phosphonates were computed, and a good correlation between calculated and experimental pKa values was found. The calculated C?H acidities increased in the sequence 2 < 1 < 3 . Diethyl fluoronitromethylphosphonate ( 3 ) was applied in the Horner–Wadsworth–Emmons reaction with aldehydes and trifluoromethyl ketones to provide new 1‐fluoro‐1‐nitroalkenes with good to high stereoselectivities. Alkylation of 3 was successful only with iodomethane, however, conjugate additions of 3 to Michael acceptors such as α,β‐unsaturated carbonyl compounds, sulfones, and nitro compounds allowed access to variously modified diethyl 1‐fluoro‐1‐nitrophosphonates. 相似文献
17.
The Stobbe condensation1 is a classical reaction of the mono-enolate, l, of diethyl succinate, generated in situ by action of alkoxide bases, with aldehydes or ketones (eq 1). 相似文献
18.
Krylov A. S. Tolstyakov V. V. Gurzhiy V. V. Dogadina A. V. 《Russian Journal of General Chemistry》2021,91(1):72-76
Russian Journal of General Chemistry - A series of new 6-phosphonylated 1H-imidazo[2,1-c][1,2,4]triazoles was synthesized by the reaction of diethyl chloroethynylphosphonate with 2-substituted... 相似文献
19.
二乙基二硫代氨基甲酸钠水相光度法测定微量Cu(Ⅱ) 总被引:4,自引:0,他引:4
研究了PH8.50的氮性介质中,在非离子表面活性剂TritonX-100存在下,Cu(Ⅱ)与二乙基二硫代氨基甲酸钠显色,水相测定微量Cu(Ⅱ)的新方法。 相似文献
20.
N. G. Khusainova V. A. Burilov D. I. Samigullin 《Russian Journal of Organic Chemistry》2018,54(1):149-150
Benzimidazole reacted with diethyl vinylphosphonate to give diethyl 2-(1H-benzimidazol-1-yl)- ethylphosphonate. The addition of 2-aminobenzimidazole to vinylphosphonate involved the endocyclic nitrogen atom with formation of diethyl 2-(2-imino-2,3-dihydro-1H-benzimidazol-1-yl)ethylphosphonate. 相似文献