有机磷化合物的研究XXII: 亚甲基双(膦酸二烷基酯)及其衍生物

研究了从甲基膦酸二乙酯衍生的碳阴离子的磷酰化合成亚甲基双(膦酸二烷基酯)(1)的新方法.     

有机磷化合物的研究 ⅠⅣ.合成烷基膦酸单酯衍生物的新方法

Atherton与Todd等1945年就用亚磷酸二烷基酯在四氯化碳中与有机胺反应得到二烷基磷酰胺.我们曾成功地由二烷基亚磷(膦)酸在四氯化碳存在下与多种亲核试剂反应合成二烷基磷(膦)酸酯及其衍生物.实验表明二烷基亚膦酸的反应性和亚磷酸二烷基酯有很大差别,为进一步考察不同的三配位磷化合物在该反应中的反应性能,我们合成了己基亚膦酸单烷基酯并在四氯化碳中与各种亲核试剂进行氧化膦酰化反应,制得了相应的己基膦酸单酯衍生物,得率良好,为合成烷基膦酸单酯衍生物的新方法.     

苯基及邻位取代苯基膦酸单烷基酯的合成及其萃取稀土的性能

提出了制备具长碳链酯烷基的烃基膦酸单烷基酯的合成方法。按此法合成了高纯度的苯基膦酸单(2-丁基辛基)酯、苯基膦酸单(1-甲基月桂基)酯、邻甲苯基膦酸单(2-丁基辛基)酯及邻甲苯基膦酸单(1-甲基月桂基)酯,考察了它们对以镧、镨、钕及镥为代表的轻、重稀土的萃取性能,并研究了萃取配合物的组成、结构和萃取分离稀土的机理。     

相转移催化合成苯基烷氧羰基甲基次膦酸酯和二苯基烷氧羰基甲基氧化叔膦

液-液相转移催化 P-烷基化反应的研究工作还不多。Kem 等曾用亚磷酸二烷基酯或二烷基氧化膦与氯代的取代乙酰胺通过液-液相转移法合成了取代胺基羰基与甲基膦酸酯及氧化叔膦。我们曾研究了亚膦酸二烷基酯与氯     

有机磷化合物的研究 ⅩⅩⅡ.亚甲基双(膦酸二烷基酯)及其衍生物

亚甲基双(膦酸二烷基酯)及其衍生物是一类能以通式1表示的化合物,其中1a、1b及1c、1d分别可视为丙二酸酯及乙酰乙酸酯的磷类似物,它们是重要有机合成试剂及金属配位体,但是这类化合物的研究与应用受到其合成方法的限制.本文报道基于甲基膦酸二乙酯(2)碳阴离子的磷(膦)酰化反应合成1的新方法.1的C-烷基化可得预期的3,后者也可由烷基膦酸二乙酯(4)的碳阴离子反应而得,或由二苯基膦酰氯经甲基化及相继的碳阴离子磷酰     

有机磷化合物的研究 Ⅷ.酸性有机磷化合物的气相色谱

酸性磷(膦)酸酯与四甲基氢氧化铵的甲醇溶液反应制得的四甲基铵盐溶液,热解转化成O-甲基化产物用气相色谱鉴定。分离与鉴定了磷酸二烷基酯、磷酸单烷基酯、烷基膦酸单烷基酯和二烷基膦酸等,并讨论了烷基碳原子数和烷基的空间效应对校正保留时间(t′_R)及保留指数(I)的影响。     

有机磷化合物的研究(LVII)——二苯(氧)基氯膦对肟基的自由基加成——合成1-氨基取代三烷基氧化膦及烷基膦酸酯的新途径

二苯基氯膦或二苯氧基氯膦对醛(酮)肟的反应可作为合成1-氨基烷基二苯基氧化膦或1-氨基烷基膦酸二苯酯的新方法,具有条件温和、操作方便及得率高的优点。EPR研究结果揭示了这类反应属自由基机理。     

酸性磷(膦)酸酯的合成及其化学结构与萃取钕、钐、镱和钇的性能研究

本文在研究二烷基磷酸、烷基膦酸单烷基酯、二烷基膦酸、单烷基磷酸与单烷基膦酸五种类型酸性磷(膦)酸酯的合成与纯化的基础上,考察了它们的缔合度和萃取稀土的机理,并计算了萃取钕、钐、镱和钇的平衡常数和分离因数。酸性磷(膦)酸酯萃取稀土的平衡常数与其反应基团解离常数密切有关,它们与取代基常数、磷(膦)酸基氧原子电荷密度间均有良好线性关系。酸性磷(膦)酸酯的结构空间位阻对萃取稀土的性能有显著影响。所研究磷(膦)酸酯萃取稀土的选择性随其平衡常数的增大而下降,符合文中提出的溶剂萃取中的反应性-选择性原理。     

改进的亚磷酸二乙酯法合成亚甲基二膦酸四乙酯

改进的亚磷酸二乙酯法合成亚甲基二膦酸四乙酯刘国正（北京师范大学化学系北京１００８７５）关键词亚甲基二膦酸四烷基脂，亚磷酸二乙酯，合成ＭＤＰ（ＭｅｔｈｙｌｅｎｅＤｉｐｈｏｓｐｈｏｎａｔｅｓ）的四烷基酯是颇具实用价值的化合物，它与活泼金属反应可生成盐，可...     

有机磷化合物的研究Ⅲ.N,N-双取代氨甲基膦酸酯及其衍生物

本文报告某些N,N-双取代氨甲基膦酸酯及其衍生物的红外光谱的研究.N,N-双取代氨甲基膦酸一烷基酯在2500厘米~(-1)左右显示宽广的NH吸收,在1210-1230厘米~(-1)及1060-1090厘米~(-1)分别显示POO~-不对称及对称吸收,其钠盐在2500厘米~(-1)左右无吸收,而在1200-1225厘米~(-1)及1060-1080厘米~(-1)也分别显示POO~-不对称及对称吸收,这些结果表明N,N-双取代氨甲基膦酸一烷基酯是以两性离子存在.N,N-双取代氨甲基膦酸二烷基酯及一烷基酯可用纸层析和纸电泳分离并讨论取代烷基及酯烷基与比移值及泳动度的关系.     

维生素A衍生物合成工艺的改进

维生素A衍生物合成工艺的改进;多双键烷基膦衍生物;Wittig-Horner反应     

Fluorescent penta- and hexaene fatty acids by a Wittig-Horner/elimination strategy

Molecular fluorescent probes have revolutionized biochemical and biophysical studies in the last decades, but with regard to lipids there has been a lack of combining the slim shape of saturated acyl chains with fluorescent properties. Our strategy to pentaene and hexaene fatty acids builds upon commercially available 4-(E)-decenal, which is subjected to a Wittig-Horner reaction after chlorination in α-position. DBU-mediated β-elimination of HCl proceeding the olefination establishes a highly conjugated system to which a salt-free Wittig reaction adds a final double bond leading to a good (Z)-selectivity of 83-86%. The double bond geometry can be optionally isomerized with I(2) to furnish the all-(E)-species. The five conjugated alkene moieties result in a longest-wavelength absorption maximum of about 350 nm. A red-shift to 380 nm was realized by addition of another double bond employing a common Wittig-Horner prolongation sequence. Stokes shifts of about 7300 and 7800 cm(-1), respectively, were observed.     

Highly Stereoselective Synthesis of E-α,β-Uksaturated Nitriles from Diphenyl Cyanomethyl Phcsphine Oxide.

The Wittig-Horner reaction from diethyl cyanomethyl phosphonate 1a and aldehydes is seldom highly stereoselective¹. The use of diiscpropyl cyanomethyl phosphonate 1b has been recently proposed to improve the stereoselectivity of the reaction towards the E-α, β- unsatured nitriles 2E².     

Synthesis and herbicidal activities of methyl-1-(2,4-dichlorophenoxyacetoxy)alkylphosphonate monosalts

A series of 1-(2,4-dichlorophenoxyacetoxy)alkylphosphonic acid dimethyl esters 5 and its corresponding phosphonate monosalts 6 were synthesized as potential herbicide. The phosphonate monosalts can be prepared from 1-(2,4-dichlorophenoxyacetoxy)alkylphosphonic acid dimethyl esters 5, which were synthesized by the condensation of O,O-dimethyl-1-hydroxyalkylphosphonates with dichlorophenoxyacetic chloride. This method provides a simple and efficient procedure for the synthesis of phosphonate derivatives containing sensitive groups to acid, base or water such as carboxylate ester bond; and the herbicidal activity of title compounds was evaluated in a set of experiments in greenhouse. Most of the compounds exhibited notable herbicidal activity.     

The direct determination of double bond positions in lipid mixtures by liquid chromatography/in-line ozonolysis/mass spectrometry

The direct determination of double bond positions in unsaturated lipids using in-line ozonolysis-mass spectrometry (O₃-MS) is described. In this experiment, ozone penetrates through the semi-permeable Teflon AF-2400 tubing containing a flow of a solution of fatty acid methyl esters (FAME). Unsaturated FAME are thus oxidized by the ozone and cleaved at the double bond positions. The ozonolysis products then flow directly into the atmospheric pressure photoionization (APPI) source of a mass spectrometer for analysis. Aldehyde products retaining the methyl ester group are indicative of the double bond positions in unsaturated FAME. For the first time, O₃-MS is able to couple directly to high performance liquid chromatography (HPLC), making the double bond localization in lipid mixtures possible. The application of LC/O₃-MS has been demonstrated for a fat sample from bovine adipose tissue. A total of 9 unsaturated FAME including 6 positional isomers were identified unambiguously, without comparison to standards. The in-line ozonolysis reaction apparatus is applicable to most mass spectrometers without instrumental modification; it is also directly compatible with various LC columns. The LC/O₃-MS method described here is thus a practical, versatile and easy to use new approach to the direct determination of double bond positions in lipids, even in complex mixtures.     

New practical access to 2-azatryptophans and dehydro derivatives via the Wittig-Horner reaction

The Wittig-Horner reaction of protected 3-formylindazoles 1 with (±)-N-(benzyloxycarbonyl)-α-phosphonoglycine trimethyl ester 2 has been developed as a new practical synthesis of dehydro 2-azatryptophans and amino acid derivatives. The preparation of 5-bromo-3-formylindazole is discussed.     

Synthesis of 2,2′-Biindolyls; Potential Intermediates for Indolocarbazole Alkaloids

The synthesis of 2,2′-biindolyls oxygenated in the benzenoid ring is reported. Wittig-Horner reaction of the phosphonate esters of 1-benzenesulfonyl-2- bromomethyl-3-substituted indoles with o-nitrobenzaldehydes followed by deoxygenation with triethyl phosphite gave 2,2′-biindolyls.     

蔗糖酯合成新方法的研究

本法以苛性钾与脂肪酸甲（乙）酯首先反应生成的部分中性皂作为乳化分散剂，使蔗糖和脂肪酸甲（乙）酯在熔融状态下直接发生酯交换反应合成蔗糖酯．适宜的反应条件为：蔗糖／硬脂酸甲酯／苛性钾／催化剂的摩尔比１：（１～２）：（０．４～０．６）：０．００３６；１３５～１４０℃、２６６６～６６６５Ｐａ负压下反应３～３．５ｈ。所得粗产物含蔗糖酯５５％，其中单酯６２％。     

Total syntheses of epothilones B and d

A convergent, total synthesis of epothilones B (2) and D (4) is described. The key steps are Normant coupling to establish the desired (Z)-stereochemistry at C12-C13, Wadsworth-Emmons olefination of methyl ketone 28 with the phosphonate ester 8, diastereoselective aldol condensation of aldehyde 5 with the enolate of keto acid derivatives to form the C6-C7 bond, selective deprotection of acid 52, and macrolactonization.     

Probing the nature of the Co(III) ion in corrins: the structural and electronic properties of dicyano- and aquacyanocobyrinic acid heptamethyl ester and a stable yellow dicyano- and aquacyanocobyrinic acid heptamethyl ester

A stable yellow derivative of cobyrinic acid heptamethyl ester, (5R,6R)-Coα,Coβ-dicyano-5,6-dihydro-5-hydroxy-heptamethylcob(III)yrinate-c,6-lactone (DCSYCbs), was prepared from dicyanocobyrinic acid heptamethyl ester (DCCbs). The C5 carbon is oxidized and the c side chain cyclized to form a lactone at C6; the 13 atom, 14 π-e(-) delocalized system of corrins is interrupted, giving a triazamethine system with four conjugated double bonds between N22 and N24 and an isolated double bond between N21 and C4. Stable yellow aquacyanocobyrinic acid heptamethyl ester (ACSYCbs) was prepared by driving off HCN with N(2) in a methanol/acetic acid solution. The electronic spectra of DCCbs and DCSYCbs appear similar except that the bands in DCSYCbs are shifted to shorter wavelengths and the γ-band is much less intense. The experimental spectra were adequately modeled using TD-DFT at the PBE1PBE/6-311G(d,p) level of theory. DCSYCbs crystallizes in the space group P2(1)2(1)2(1) (R(1) = 6.08%) with Z = 4, including one methanol solvent molecule and one water molecule per cobester. The addition of a hydroxyl group at C5 causes loss of the double bond between C5 and C6 and elongation of the C5-C6 bond. From a combination of two-dimensional (1)H TOCSY and ROESY NMR spectra and (1)H/(13)C HSQC and HMBC data, the complete (1)H and (13)C NMR assignments of DCSYCbs were possible, except for two of the ester methyl groups and the (13)C resonances of the two axial cyanide ligands. The latter were assigned using relative chemical shifts calculated by GIAO-DFT methods. The (59)Co resonance of DCCbs was observed at 4074 ppm while that of DCSYCbs is shifted downfield to 4298 ppm. Comparison with available (59)Co data of analogous systems suggests that the more π-conjugated corrin of DCCbs interacts more strongly with the metal than the less extensively conjugated macrocycle of DCSYCbs. As the strength of the interaction between Co(III) and an equatorial macrocycle increases, ν(CN) of axially coordinated CN(-) shifts to lower frequency; in DCSYCbs and DCCbs ν(CN) occurs at 2138 and 2123 cm(-1), respectively. Hence the corrin ligand in DCCbs interacts more strongly with the metal than the stable yellow corrin ligand, with its diminished conjugation. The UV-vis spectral data and DFT-calculated MOs are consistent with greater overlap between the corrin and the metal orbitals in DCCbs relative to DCSYCbs, which gives the metal in the former a softer, more covalent character.