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1.
Five chiral -D-glucose-based monoaza-15-crown-5 ethers with phosphinoxidoalkyl side chains of one to five carbon atoms (5a–e)have been synthesised. The cation binding ability of the new lariat ethers was evaluated bythe picrate extraction method. The substituents at the nitrogen atom were not a major influenceon the cation extraction ability of the azacrown ether; the compounds showed, however, a significant asymmetric induction as phase transfer catalysts in the Michael addition of2-nitropropane to chalcone (95% ee).  相似文献   

2.
The alkali metal- and ammonium picrate extracting ability of d-glucose- and d-mannose-based 15-crown-5 ethers and related lariat ethers was investigated in dichloromethane – water system. A heteroatom was waried in the crown ether containing a 4,6-O-benzylidene-α-d-glucopyranoside unit 6, (X=O), 2 (X=S) and 8a (X=NH). Extracting ability of the latter species (8a) was excellent (97–99%) in regard of all cations (Li+, Na+, K+, Rb+, Cs+ and NH4+) examined, it was not, howewer, selective. Introduction of a side arm on the nitrogen atom of 8a decreased the extracting ability, but increased the selectivity. In this series of compounds (8bf, 4), 4 with a pyridylethyl substituent allowed the extraction of sodium picrate in 72%. The glucose-based macrocycles 8a, 8e and 8f formed a stronger complex with the cations examined than the mannose-based analogues 9a, 9e and 9f, that can be explained by the all-gauche conformation of the former ones. It was pointed out that in the case of crowns with tertiary amine moieties, the basicity increases the quantity of the picrates extracted. According to complex forming measurements by FAB-MS, the best sodium ion selectivity was achieved by the γ-hydroxypropyl substituted lariat ether (8e). Possible structures of the complexes formed by the two types of monosacharides with sodium cation were evaluated by molecule modelling calculations.  相似文献   

3.
以松香为原料, 合成了4个手性氮杂冠醚: N-脱氢松香基单氮杂-12-冠-4、N-脱氢松香基单氮杂-15-冠-5、N-脱氢松香基单氮杂-18-冠-6和N-降解脱氢松香基单氮杂-12-冠-4, 并用于催化不对称查尔酮Michael加成反应, 发现这些手性氮杂冠醚可以有效地催化2-硝基丙烷与查尔酮的不对称Michael加成, Michael加成产物ee最高达35%.  相似文献   

4.
A new complex of a chiral monoaza-crown ether, [R-(-)-2-ethyl-N-benzyl-4,7,10,13-tetraoxa-1-azacyclopentadeceane) NaClO4], has been prepared and studied by x-ray diffraction. The compound crystallizes in space group P21 with cell dimensions a = 9.480(1), b = 15.978(2), c = 15.816(2) Å, = 105.51(1)°, Z = 4. The final R value is 0.055 for 2711 observed reflections and 540 parameters. There are twomolecules in the asymmetric unit labelled A and B. The sodium ion is hexacoordinated. The average values for the Na–-Oeth (etheric) distances are 2.364(6), 2.317(7) Å and the Na–N distances are 2.679(6), 2.611(7) Å; the Na–-O(ClO4) contacts are2.497(7) and 2.257(10) Å, for A and B, respectively.  相似文献   

5.
Carbohydrate-based crown ethers have been reported to be able to generate asymmetric induction in certain reactions. Previously, it was proved that the monosaccharide unit, the anomeric substituent, and the sidearm could influence the catalytic activity of the monoaza-15-crown-5 macrocycles derived from sugars. In order to gain information about the effect of the flexibility, 4,6-di-O-ethyl-glucoside-based crown compounds were synthesized, and their efficiency was compared to the 4,6-O-benzylidene analogues. It was found that the absence of the two-ring annulation has a negative effect on the enantioselectivity in liquid-liquid two-phase reactions: in the Darzens condensation of 2-chloroacetophenone and in the epoxidation of chalcone. The same trend was observed in the solid-liquid phase Michael addition of diethyl acetamidomalonate. Surprisingly, in the solid-liquid phase cyclopropanation of benzylidenemalononitrile, one of the new catalysts was highly enantioselective (99% ee).  相似文献   

6.
由(+)-2-氨基丁醇合成氮杂手性冠醚   总被引:2,自引:0,他引:2  
赵冬  尹承烈 《有机化学》1991,11(3):310-313
手性冠醚由于具有手性识别和不对称催化有机反应的性质而受到人们的重视,有关它们的合成及性质,已很多论述。氮杂冠醚则是合成穴醚、双冠醚、套索冠醚(LariatEther)等的重要中间体,也可与高分子材料(高分子载体或高分子基质)连接,用于有机化合物的色谱分离。氮杂手性冠醚兼备手性和氮杂冠醚两种特性,而可能具有广泛的用途。  相似文献   

7.
Azacrown ethers with phosphonoalkyl-and phosphinoylalkyl side chains of two to five carbonatoms (2–4, 7 and 5–6, 8,respectively) were synthesized in acceptable yields.The cation binding ability of the new lariat etherswas evaluated by the picrate extraction method.Introduction of the P-functionalised N-substituentresulted in a decrease in the cation extractionability in most cases, but the discrimination betweenthe cations examined was, in some instances,significantly increased.  相似文献   

8.
以2-苯氧乙醇为起始剂, 合成了两种新型氮支套索冠醚: N-(2-苯氧乙基)单氮杂-18-冠-6 (18CE)与N-(2-苯氧乙基)单氮杂-15-冠-5 (15CE). 通过红外光谱、核磁共振氢谱和紫外光谱表征了新冠醚及其中间体的结构. 用电导滴定法研究了两冠醚与Na, K, Ag, NH4+, Ni2+, Cu2+, Pb2+和Co2+在25 ℃的配位作用, 计算了1∶1配合物的稳定常数. 实验结果表明, 由于N-(2-苯氧乙基)引入氮杂冠醚环和参与配位, 18CE和15CE配合物的稳定常数分别比单氮杂-18-冠-6, N-(2-羟基乙基)单氮杂-18-冠-6, N-(2-甲氧基乙基)单氮杂-18-冠-6和单氮杂-15-冠-5, N-(2-甲氧乙基)单氮杂-15-冠-5, N-(2-甲氧乙基)单氮杂-15-冠-5的对应配合物明显提高. 配合物的稳定常数和紫外光谱皆提供了支链的苯氧基参与配位的信息.  相似文献   

9.
A simple and efficient synthetic protocol for an easy access of carbohydrate-linked crown ethers from cheap and readily available D-glucose in good yields has been devised. The base-mediated cyclization of sugar-linked bis-iodo podands in CH3CN with amines, including ethylamine and furfurylamine afforded the novel chiral monoaza-15-crown-5-type macrocyclic crown ethers anellated to 3-O-benzyl-1,2-O-isopropylidene-α-D-glucofuranose and 3-O-benzyl-1,2-O-isopropylidene-α-D-allofuranose. The glucose-based crown ethers have been characterized by spectroscopy techniques including IR, 1H NMR, and 13C NMR.  相似文献   

10.
The synthesis of azacrown ethers with phosphonoalkyl side chains of two to five carbon atoms ( 3–8, 10), potentially useful as a new type of cation binding agent, is described. Introduction of the phosphonoalkyl moiety into the parent monoaza-15-crown-5 ( 1) decreases the cation extraction ability, but results in an increase in the selectivity towards the cations examined. The effect of the phosphonoalkyl-azacrown ethers on the properties of membranes used in ion-selective electrodes is also reported.  相似文献   

11.
Details of a new synthetic approach to 4,10,16-triaza-18-crown-6 (triaza-18-crown-6) are reported, along with the preparation and binding properties of the following derivatives having the indicated sidearms: CH2CCH, CH2CH2OH, CH2CH2OCH3, COCH2OCH3,CH2COOCH2CH3, CH2C6H5, and CH2C6H4–2–NO2. A key intermediate in the synthesis of triaza-18-crown-6 is 4-N-toluenesulfonyl-1,7,13-trioxa-4,10,16-triazacyclooctadecane-9,17-dione. This compound is found by solid state structure analysis to fold to form an intramolecular, doubly-hydrogen bonded complex in which the two N-H protons interact with the two tosyl group oxygens. Details of the structure are reported.This paper is dedicated to the memory of the late Dr C. J. Pedersen.  相似文献   

12.
A new complex of a chiral monoaza-crown ether, [R-(-)-2-ethyl-N-benzyl-4,7,10,13-tetraoxa-8,9-benzo-1-azacyclopentadec-8-ene...NaClO4], has been prepared and studied by x-ray diffraction. The compound crystallizes in space group P21 with cell dimensions a = 8.721(1), b = 16.318(2), c = 8.905(1) Å, = 100.80(1)°. The sodium cation is heptacoordinated and located significantly out of the best plane of the macrocycle ring. The donor atoms of the macrocycle are in the half-chair arrangement.  相似文献   

13.
综述了N-取代氮杂冠醚的合成和对金属离子的选择性络合和萃取研究的新进展.  相似文献   

14.
魏太保  王军  罗榕  张有明 《有机化学》2007,27(11):1381-1385
由苯并-15-冠-5经磺酰化、肼解两步合成了4'-磺酰肼苯并-15-冠-5 (2). 后者与芳香醛在室温下发生缩合制得了一系列未见文献报道的冠醚化磺酰腙类化合物3a3h, 产物经元素分析, IR, 1H NMR, 13C NMR, MS确证了其结构. 利用紫外-可见吸收光谱考查了其对不同阴离子的识别作用, 结果表明, 化合物3d, 3e, 3h对碱性较强的阴离子有较强的选择性识别作用.  相似文献   

15.
4'-磺酰腙苯并-15-冠-5的合成及阴离子识别研究   总被引:1,自引:1,他引:1  
由苯并-15-冠-5经磺酰化、肼解两步合成了4’-磺酰肼苯并-15-冠-5(2).后者与芳香醛在室温下发生缩合制得了一系列未见文献报道的冠醚化磺酰腙类化合物3a~3h,产物经元素分析,IR,1H NMR,13C NMR,MS确证了其结构.利用紫外-可见吸收光谱考查了其对不同阴离子的识别作用,结果表明,化合物3d,3e,3h对碱性较强的阴离子有较强的选择性识别作用.  相似文献   

16.
苯并15-冠-5与Na_2[M(SCN)_4](M=Pd,Pt)配合物的合成与结构   总被引:2,自引:0,他引:2  
合成了苯并15-冠-5与Na_2[M(SCN)_4] (M = Pd, Pt)生成的配合物:[Na(B15- C-5)]_2[Pd(SCN)_4] (1), {[Na(B15-C-5)][Na(B15-C-5)(H_2O)]}[Pt(SCN)_4] (2)。1为单斜晶系,空间群P2_1/n,a = 1.0164(6) nm,b = 1.3743(3) nm,c = 1.4987(7) nm,β = 95.248(6)°,V = 2.0847 nm~3,Z = 2,D_(calcd) = 1. 47 g/cm~3,F(000) = 944,R = 0.053,wR = 0.072。2为三斜晶系,空间群P(1- bar),a = 1.1484(2) nm,b = 1.4210(3) nm,c = 1.5026(3) nm,α = 62.500 (3)°,β = 72.393(3)°,γ = 73.106(4)°,V = 2.0398(7) nm~3,Z = 2, D_(calcd) = 1.674 g/cm~3,F(000) = 1028,R_1 = 0.0327,wR_2 = 0.0885。1 由两个[Na(B15-C-5)]~+配阳离子和一个[Pd(SCN)_4]~(2-)配阴离子组成,两者通 过Na-N键形成中性配合物,[Na(B15-C-5)]~+A相对钯原子呈反式排列。2由[Na (B15-C-5)]~+和[Na(B15-C-5)(H_2O)]~+配阳离子和一个[Pt(SCN)_4]~(2-)配阴离 子组成,它们也通过Na-N键形成中性配合物,配阳离子相对铂原子呈顺式排列。2 的两个分子通过氢键形成二聚结构。  相似文献   

17.
Crown ether derivatives have been extensively developed to provide enhanced structural recognition of substrate alkyl-ammonium cations. In particular a number of investigations of complexation of chiral alkylammonium salts by chiral crown ethers have been reported. The enantioselectivity has been applied in the chromatographic resolution of amino acid perchlorates. In general the crown ethers used in these studies have been based upon derivatives of 2, 2′-dihydroxy-1, 1′-binaphthyl1 or deriv…  相似文献   

18.
王成云  汪大翚  冷桃花  俞庆森 《有机化学》2005,25(11):1473-1476
(S)-苯丙氨醇和原氯乙酸三乙酯作用得到的手性酰胺醇和手性噁唑啉分别与1,7-二氮-12-冠-4反应, 得到了两种手性N,N′-双支套索冠醚N,N′-二[(S)-N-(1-羟甲基-2-苯基乙基)乙酰胺-2]-1,7-二氮-12-冠-4 (1a)和N,N′-二[(S)-4-苄基-噁唑啉-2-亚甲基]-1,7-二氮-12-冠-4 (1b). 前者应用于D/L-肉碱的手性分离; 后者的铜配合物用于重氮醋酸酯对烯烃的不对称环丙烷化反应.  相似文献   

19.
A novel series of benzo crown ether (dibenzo 18-crown-6 ether, benzo 18-crown-6 ether, and benzo 15-crown-5 ether) functionalized enamines derivatives from amino benzo crown ether (4-amino dibenzo 18-crown-6 ether, 4-amino benzo 18-crown-6 ether, 4-amino benzo 15-crown-5 ether) and substituted 3-(dimethylamino)-1-phenylprop-2-en-1-one compounds have been synthesized. All the synthesized compounds were characterized by infrared, 1H NMR, 13C NMR, distortionless enhancement polarization transfer, and mass and elemental analysis techniques. The cation recognition property for benzo crown ether enamine 8a was studied by absorption and fluorescence spectroscopy.  相似文献   

20.
EDTA脱水成二酐后,与多缩乙二醇或α,ω-二胺反应,分别得到了大环醚双内酯(Ⅰ—Ⅳ)和大环胺双内酰胺(Ⅴ—Ⅷ)。各产物的结构均经红外、核磁、分子量和元素分析鉴定。  相似文献   

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