首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Phosphinic and phosphonic acids are useful intermediates and biologically active compounds which may be prepared from their esters, phosphinates and phosphonates, respectively, by hydrolysis or dealkylation. The hydrolysis may take place both under acidic and basic conditions, but the C-O bond may also be cleaved by trimethylsilyl halides. The hydrolysis of P-esters is a challenging task because, in most cases, the optimized reaction conditions have not yet been explored. Despite the importance of the hydrolysis of P-esters, this field has not yet been fully surveyed. In order to fill this gap, examples of acidic and alkaline hydrolysis, as well as the dealkylation of phosphinates and phosphonates, are summarized in this review.  相似文献   

2.
An efficient approach to a new series of benzothiazaphosphepines and their derived phosphonates in good yields (64–75%) was reported. The strategy relied on the reactions of the easily available 2-arylmethylene-aminobenzenethiols with different types of Wadsworth–Horner–Emmons (WHE) reagents in dimethylformamide (DMF)/lithium hydride (LiH) solution. All new compounds were bioscreened and showed, in vitro, moderate to good antioxidant and antidiabetic activities.  相似文献   

3.
A one-pot sequential strategy to construct phosphonamidates has been developed by generating phosphonites in situ from arylmagnesium bromides and triethyl phosphite followed by treatment with iodine and amines. A variety of phosphonamidates were obtained with good to excellent yields at room temperature from easily available materials.  相似文献   

4.
A strategy for the direct functionalization strategy of inertial dialkyl phosphonates with hydroxy compounds to afford diverse mixed phosphonates with good yields and functional‐group tolerance has been developed. Mechanistic investigations involving both NMR studies and DFT studies suggest that an unprecedented highly reactive PV species (phosphoryl pyridin‐1‐ium salt), a key intermediate for this new synthetic transformation, is generated in situ from dialkyl phosphonate in the presence of Tf2O/pyridine.  相似文献   

5.
微波辐射下1-氨基烷基膦酸酯的一锅合成   总被引:3,自引:0,他引:3  
顾大公  纪顺俊  史海斌  周民锋 《合成化学》2005,13(2):185-186,195
以醛、胺及膦酸二乙酯为原料,微波辐射3min~5min,高产率地一锅合成了一系列的1.氨基烷基膦酸酯。其结构经^1HNMR,IR和元素分析表征。  相似文献   

6.
王国芝  胡继文 《广州化学》2010,35(2):23-26,30
在室温下,二氟溴甲基膦酸二乙酯与锌粉反应生成锌试剂;2,4-二硝基氯化苄与合成的锌试剂在溴化亚铜催化作用下即可反应生成二硝基苯乙基(氟代)磷酸二乙酯化合物。两步反应都可在室温下进行,操作简单易行。  相似文献   

7.
We report a method for the selective α,β‐dehydrogenation of amides in the presence of other carbonyl moieties under mild conditions. Our strategy relies on electrophilic activation coupled to in situ selective selenium‐mediated dehydrogenation. The α,β‐unsaturated products were obtained in moderate to excellent yields, and their synthetic versatility was demonstrated by a range of transformations. Mechanistic experiments suggest formation of an electrophilic SeIV species.  相似文献   

8.
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   

9.
Short and efficient syntheses of functionalized (pyrrolidin-2-yl)phosphonate and (5-oxopyrrolidin-2-yl)phosphonate have been developed. The synthetic strategy involved the diastereospecific 1,3-dipolar cycloaddition of N-benzyl-C-(diethoxyphosphoryl)nitrone to cis-1,4-dihydroxybut-2-ene and dimethyl maleate, respectively. O,O-Diethyl 3-carbamoyl-4-hydroxy(5-oxopyrrolidin-2-yl)phosphonate was obtained from O,O-diethyl 2-benzyl-4,5-dimethoxycarbonyl(isoxazolidin-3-yl)phosphonate by hydrogenation and subsequent treatment with ammonia, whereas transformation of O,O-diethyl 2-benzyl-4,5-dihydroxymethyl(isoxazolidin-3-yl)phosphonate into O,O-diethyl 3-aminomethyl-4-hydroxy(pyrrolidin-2-yl)phosphonate was accomplished by mesylation followed by hydrogenolysis to undergo intramolecular cyclization and the introduction of amino group via ammonolysis. Stereochemistry of the isoxazolidine cycloadducts, as well as the final functionalized (pyrrolidin-2-yl)- and (5-oxopyrrolidin-2-yl)phosphonates were established based on conformational analyses using vicinal H–H, H–P, and C–P couplings and supported by the observed diagnostic NOESY correlation signals.  相似文献   

10.
11.
Two new manganese(II) phosphonates, (NH4)Mn2.5[(O3PCH(OH)CO2)2(H2O)] ( 1 ) and [NH3(CH2)4NH3]0.5Mn2.5[(O3PCH(OH)CO2)2(H2O)] ( 2 ) have been synthesized under hydrothermal conditions and structurally characterized by single‐crystal X‐ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. The two isomorphous compounds feature a 3D framework structure. The Mn(1)O6 and Mn(3)O5 polyhedra are bridged by the CPO3 tetraheda into a MnII phosphonate layer in ac‐plane. Mn(2)O6 polyhedra are linked to each other by CPO3 tetraheda to form infinite chains, which are connected to layers by carboxylate groups to form a 3D framework structure with channels along the a‐ and c‐axis, respectively. The NH4+ ions or protonated 1, 4‐butylenediamine cations are located inside the channels along the a axis.  相似文献   

12.
Abstract

Furolignan-type natural products, possessing important biological properties, have been synthesized from a commercially available furan. The elaborated synthetic strategy is based on an innovative Friedel-Crafts reaction starting from an alcohol or a carboxylic acid and triflic anhydride as promoter. Through this synthetic strategy, furolignans having two different aryl groups have been obtained. The products have been evaluated for their antimicrobial properties on Gram positive and Gram negative bacteria, in order to compare their biological activities with those of natural analogues.  相似文献   

13.
The synthetic utility of trifluoromethanesulphonic anhydride (triflic anhydride, TA) without additive or base for the high-yielding synthesis of a wide variety of 1,2-benzisoxazoles from 2-hydroxyaryl aldoximes and ketoximes under mild conditions has been carried out for the first time. As a continuation of our study, syntheses of isoxazolo and isothiazolo quinolones have also been demonstrated using triflic anhydride under similar conditions. This method is simple and has benefits from the easy way to isolate the products in excellent yields.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]  相似文献   


14.
多氨基多醚基亚甲基膦酸的合成及其阻垢机理的MD模拟   总被引:4,自引:2,他引:4  
雷武  张曙光  夏明珠  王风云 《化学学报》2006,64(12):1291-1298
以端氨基聚醚、亚磷酸、甲醛、浓盐酸等为原料合成了新型水处理剂多氨基多醚基亚甲基膦酸(PAPEMP), 并通过红外、核磁等手段对产品进行了表征. 采用分子动力学(MD)模拟退火方法, 研究了周期性边界条件下PAPEMP与方解石晶体的相互作用, 探讨了该相互作用的本质, 并初步阐释了PAPEMP的阻垢机理. 结果发现, PAPEMP分子(n=1~8)与方解石 晶面的结合能强弱排序依次为(按聚合度) 5>6>4>3>8>2>7>1. 对体系各种相互作用以及对关联函数g(r)的分析表明, 超分子体系的结合能主要由库仑作用(包括离子键)提供, 并含少量氢键成分; van der Waals作用为正值, 不利于结合体系的形成. 能量分析表明, 与方解石晶面结合的PAPEMP (n=1~8)分子均发生了明显的扭曲变形.  相似文献   

15.
A mild and efficient method for diacetylation reaction was developed,by which diacetate could be achieved through the reaction of aldehyde with acetic anhydride,in the presence of cobalt sulfate,with an admirable yield,at room temperature,without solvent.The catalyst could be recycled six times without a distinct loss of activity.  相似文献   

16.
A direct access to P-glycosyl-, P, P-di-glycosyl alkenylphosphonates and P, C-glycosyl phosphonates is described. The method involves the Horner reaction of an anion derived from P-monoglycosyl and P 1, P′-diglycosyl methylenediphosphonates either on the exocyclic aldehyde group of carbohydrates or on the masked aldehydic form of the furanose hemiacetals. In this last case, the carbonyl olefination, followed by an intramolecular cyclization, leads to P,C-di and P,P,C-triglycosyl phosphonates.  相似文献   

17.
Two new metal phosphonates with a 3D pillared layered framework based on N,N′‐piperazinebis(methylenephosphonic acid), H2O3PCH2NC4H8NCH2PO3H2 (H4L), Sn[O3PCH2NHC4H8NHCH2PO3] ( 1 ) and Pb3(OH)2[O3PCH2NC4H8NCH2PO3] ( 2 ), have been synthesized under hydrothermal conditions and structurally characterized by single‐crystal X‐ray diffraction as well as with infrared spectroscopy, elemental analysis and thermogravimetric analysis. For compound 1 , each ψ‐square pyramidal SnO4 unit is in turn corner‐shared by four CPO3 tetrahedral from four different phosphonate ligands to form two‐dimensional inorganic puckered layers in ab planes. In compound 2 , the complicated inorganic layer (bc planes) is built up of ψ‐PbO4N, PbO6 and CPO3 polyhedra. The overall structure for two compounds may be described in terms of alternating inorganic infinite layers and organic pillars {CH2N(C2H4)2NCH2}, to form a 3D pillared layered structure.  相似文献   

18.
19.
A simple solvent ligation effect was successfully used to disrupt the growth of a model compound, Fe[(OH)(O3P(CH2)2CO2H)]?H2O (MIL‐37), into an extended 2D structure by replacing water with dimethylformamide (DMF) as the solvent during the synthesis. Owing to the lack of ?OH group, which provides the corner‐sharing (binding) oxygen atoms for the octahedra, an amorphous and porous structure is formed. When Fe3+ is partially replaced by Ni2+, the amorphous structure remains and the resultant binary metal catalyst displays excellent photocatalytic oxygen evolution activity with almost 100 % yield achieved under visible light irradiation using [Ru(bpy)3]2+ as the photosensitizer. This study opens up new possibilities of using the simple solvent effect to synthesize high surface area metal phosphonates for catalytic and other applications.  相似文献   

20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号