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41.
Well‐defined polystyrene‐ (PSt) or poly(ε‐caprolactone) (PCL)‐based polymers containing mid‐ or end‐chain 2,5 or 3,5‐ dibromobenzene moieties were prepared by controlled polymerization methods, such as atom transfer radical polymerization (ATRP) or ring opening polymerization (ROP). 1,4‐Dibromo‐2‐(bromomethyl)benzene, 1,3‐dibromo‐5‐(bromomethyl)benzene, and 1,4‐dibromo‐2,5‐di(bromomethyl)benzene were used as initiators in ATRP of styrene (St) in conjunction with CuBr/2,2′‐bipyridine as catalyst. 2,5‐Dibromo‐1,4‐(dihydroxymethyl)benzene initiated the ROP of ε‐caprolactone (CL) in the presence of stannous octoate (Sn(Oct)2) catalyst. The reaction of these polymers with amino‐ or aldehyde‐functionalized monoboronic acids, in Suzuki‐type couplings, afforded the corresponding telechelics. Further functionalization with oxidable groups such as 2‐pyrrolyl or 1‐naphthyl was attained by condensation reactions of the amino or aldehyde groups with low molecular weight aldehydes or amines, respectively, with the formation of azomethine linkages. Preliminary attempts for the synthesis of fully conjugated poly(Schiff base) with polymeric segments as substituents, by oxidative polymerization of the macromonomers, are presented. All the starting, intermediate, or final polymers were structurally analyzed by spectral methods (1H NMR, 13C NMR, and IR). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 727–743, 2006  相似文献   
42.
Zusammenfassung Perimidon (1) reagiert mit monosubstit. Malonsäure-trichlorphenylestern (2) bei 250° zu 9-Hydroxy-5,7-dioxo-4,5-dihydro-7H-pyrido[1,2,3-cd]perimidinen (3), die durch saure Hydrolyse zu 10-Amino-4-hydroxy-benzo[h]carbostyrilen (4) gespalten werden.
Syntheses of heterocycles, CXXII: Reaction of perimidone with reactive malonates
Perimidone (1) reacts with monosubstituted 2.4.6-trichlorophenyl malonates at 250° to 9-hydroxy-5.7-dioxo-4.5-dihydro-7H-pyrido[1.2.3-cd]perimidines (3), which are cleaved by acid yielding 10-amino-4-hydroxy-benzo[h]quinolin-2-ones (4).
  相似文献   
43.
A new obtusafuran derivative, lawsonicin ( 1 ), and a new naphthaquinone, lawsonadeem ( 2 ), along with a known constituent, vomifoliol ( 3 ), were isolated from the aerial parts of Lawsonia alba and characterized by chemical transformation and spectroscopic experiments, including 2D‐NMR techniques.  相似文献   
44.
The complexing process proceeding in the NiII–thiocarbohydrazide (H2N–H–NC(=S)–NH–NH2)–propanone triple system in EtOH solution and nickel(II)hexacyanoferrate(II) gelatin-immobilized matrix has been studied. It has been found that in the first case, template synthesis leading, as a minimum, to formation of three coordination compounds of NiII with (N,N,S,S)-donor tetradentate ligands having NiL1, NiL2 and NiL3compositions where L1 is 4,6,6-trimethyl-2,3,7,8-tetraazanonen-3-di(thiohydrazide)-1,9, L2 is 4,6,6,12-tetrametyl-1,9-dithio-2,3,7,8,10,11-hexaazatridekadien-3,11-hydrazide-1 and L3 is 2,8,10,10,16-pentamethyl-5,13-dithio-3,4,6,7,11,12,14,15-octaazaheptadekatrien-2,7,15 is observed, whereas in the gelatin-immobilized matrix, a complexing process in the system considered does not occur.  相似文献   
45.
Relative rates of solvolysis of some N-triorganosilylanilines in mixtures of ethanol and aqueous potassium hydroxide have been determined, with results as follows. (i) For XC6H4NHSiEt3 compounds in MeOH (5 vol) + aq. alkali (2 vol) at 50°: (X =) H, 1.0;p-Me, 0.80;p-OMe, 0.83;m-Me, 0.90; o-Me, 0.87; p-SMe, 1.90; p-F, 1.7; p-Cl, 2.8; o-Cl, 14; m-Cl, 4.2; m-NO2, 18; p-CN, ca. 43; p-NO2, ca. 120. (ii) For PhNHSi(C6H4Y)3 compounds in MeOH (10 vol) + aq. alkali (1 vol) at 50°: (Y =) H, 1.0; p-OMe, 0.12; p-Cl, ca. 32; m-Cl, ca. 84. (iii) For PhNHSiR3 compounds in MeOH (5 vol) + aq. alkali (2 vol) : (R3 =) Et3, 1.0; Et2Me, 18 (at 30°); Me2-i-Pr, 8 (at 30°);Me2-t-Bu, 0.012 (at 50°);i-Pr3, 0.006 (at 50°). In series (i) the relative rates correlate with σ, or where appropriate σ?-constants, with a ? value of 1.6. It is suggested that in the transition state of the rate-determining step the OSi bond is fully formed, or almost so, the SiN bond approximately 20—50% broken, and the bond between the nitrogen atom and a proton from the solvent ca. 10—30% formed.  相似文献   
46.
47.
The different aspects of Vitamin D3 determination and the data reported in the literature are discussed. The spectrophotometric determination of Vitamin D3 in cod-liver oil is carried out after the alkaline saponification, extraction of unsaponified parts, precipitation of accompanying sterols and the column- and thin-layer chromatographic purification and separation of vitamin D3 on 40 cm plates from other vitamins. The dyestuff α-naphtholbenzein is suited well as standard substance for the better location and identification of vitamin D3 zone on the thin-layer plate. The results obtained from the chemical method were checked through the simultaneous biological determination.  相似文献   
48.
The structure of solanoforthine, m.p. 208–10°, [α]D- 26.6°, a new steroidal alkaloid isolated from Solanum seaforthianum Andr., has been established as 3β-amino-22,26-epimino-16α,23-epoxy-22αH,25βH-cholest- 5- en -23β - ol 3, based on chemical and spectroscopic evidence and by its reduction to solanocapsine 2, another steroidal alkaloid encountered in the same species. The mass spectra of2 and 3 are discussed.  相似文献   
49.
Sharpless asymmetric dihydroxylation and aminohydroxylation of (E)-dimethyl-2-alkylidene glutarates 2 were shown to afford enantio-enriched or enantiopure highly functionalized γ-butyrolactones 3 and 7.  相似文献   
50.
Single nanocrystal arrays were fabricated on sub-microwells of poly(ethylene glycol) (PEG) copolymer using selective wetting on the hydrophilic regions of the exposed substrate surface and subsequent drying. Templates were produced by molding a thin film of a PEG-based random copolymer on hydrophilic substrates such as glass or silicon dioxide. The polymeric microstructures provide a topographical barrier around the well, which makes it possible to create nanocrystal arrays with controlled geometrical features. The size of the nanocrystal was found to decrease with decreasing well size and also decrease with decreasing topological height. A simple empirical equation was derived to predict the size of the crystal as a function of the pattern size and height, which is in good agreement with the experimental data.  相似文献   
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