Syntheses of vinyl polymers containing the N-phenothiazinyl group in the side chain

Four kinds of vinyl polymers containing N-substituted phenothiazinyl groups in side chains were obtained by syntheses of the respective monomers and subsequent polymerizations. Thus, N-acrylamidomethylphenothiazine, N-(N-acrylamidomethyl)carbamoylethyl phenothiazine, β-(N-phenothiazinyl)ethyl acrylate and methacrylate, and β-(N-phenothiazinyl)ethyl vinyl ether were synthesized. It was found that all monomers except the last monomer can be polymerized with typical free-radical initiators such as α,α′-azobisisobutyronitrile to afford stable soluble polymers with electron-donating characteristics, presumably due to the absence of a hydrogen atom at the site of the nitrogen atom of the phenothiazinyl group. The last monomer was found to be susceptible to typical cationic initiators such as boron trifluoride etherate to afford a stable soluble polymer also with the electron-donating characteristic.     

含可聚合基团的萘酰亚胺衍生物的合成

以4-溴-1,8-萘酐和4-硝基-1,78-萘酐为起始原料,与各种芳胺经亚胺化,再与脂肪胺经取代反应,最后与丙烯酰氯经酯化得到一系列具有强烈荧光的含丙烯酰氧乙基氨基的1,8-萘酰亚胺衍生物,它们可作为一种聚合荧光色素的单体。     

高效液相色谱法同时测定苏木中的巴西苏木素和原苏木素B

建立了同时测定苏木中巴西苏木素和原苏木素B的高效液相色谱检测方法。采用Agela Venusil XBP-C18(4.6 mm×150 mm,5μm)色谱柱,以甲醇-0.2%甲酸溶液为流动相,梯度洗脱,流速1.0 mL/min,测定温度为35℃,检测波长285 nm。巴西苏木素和原苏木素B的质量浓度均在0.005～1.0 mg/mL时与色谱峰面积之间线性关系良好,相关系数都为0.9999;回收率范围分别为96.7%～101.4%和99.4%～103.0%,相对标准偏差(RSD)为2.0%和1.3%。该法可以用于苏木药材的鉴定。     

Syntheses of polymerizable viologens bearing a terminal vinyl group

Viologens that bore a terminal vinyl group were synthesized by four sequences of reactions: (1) N-vinylbenzyl-N′-n-propyl-4,4′-bipyridinium bromide chloride (V) was synthesized by the reaction of 4-(4′-pyrodyl)-N-n-propyl pyridinium bromide (III) with vinylbenzyl chloride; (2) N-β-acrylamidoethyl-N′-n-propyl-4,4′-bipyridinium dibromide (IX) was synthesized by the Menschutkin reaction of III with 2-aminoethyl bromide hydrobromide and subsequent reaction with acryloyl chloride; (3) N-β-methacryloyloxyethyl-N′-n-propyl-4,4′-bipyridinium dibromide and its analogs (XI) were synthesized by the reactions of III with the corresponding acyloxyalkyl bromides; and (4) N-vinyloxycarbonylmethyl-N′-n-propyl-4,4′-bipyridinium bromide chloride (XIII) was synthesized by the reaction of III with vinyl chloroacetate. With the exception of monomer XIII in which hydrolysis in large extent was observed during attempted polymerization, the synthesized monomers polymerized smoothly in aqueous solutions by a conventional radical procedure. Comparisons of the absorption peaks of the radical cations produced by reductions in aqueous solutions with those produced in films by ultraviolet (UV) irradiation indicate that the radical cations of polymers are associated intramolecularly in aqueous solutions.     

Syntheses and characterizations of group 6 metal cyanotrihydroborate complexes

The anions, [M(CO)_6-n(NCBH₃)_n]ⁿ⁻ (n=2, M=Cr(1); n=3, M=Cr(2), Mo(3), W(4)), were prepared either from the reactions of sodium cyanotrihydroborate with group 6 transition metal hexacarbonyls, M(CO)₆ (M=Cr, Mo, W), or through the reactions of M(CO)₃(CH₃CN)₃ (M=Cr, W) with sodium cyanotrihydroborate. The cyanotrihydroborate ligand bonds to the metal through a nitrogen atom, which was confirmed by the Infrared, proton and boron NMR spectroscopies. Crystal structures of the above complexes were determined by single crystal X-ray diffraction analyses. A cis configuration is found in 1. Molecular structures of 2, 3, and 4 are similar and a facial configuration is observed.     

Syntheses and structures of triazides of heavy group 15 elements

Synthesis of group 15-triazides E(N(3))(3) (E = Sb 1, Bi 2) and Py(2)-Bi(N(3))(3)3 (Py = pyridine). Single crystals of 1 were in situ grown by an IR-laser-assisted technique on the diffractometer. The structure of 3, which represents the first structurally characterized neutral Bi-triazide, is influenced by crystal packing effects according to DFT calculations.     

Analysis of brazilin and protosappanin B in sappan lignum by capillary zone electrophoresis with acid barrage stacking

A method was developed to determine brazilin and protosappanin B in natural products by CE after acid barrage stacking. The optimum conditions were as follows: a BGE of 20 mM sodium tetraborate (pH 9.2) containing 6% v/v of methanol, hydrodynamic injection (0.5 psi, 65 s) followed by hydrodynamic injection of 150 mM citric acid (pH 2.3; 0.5 psi, 22 s), and separated with +25 kV. Under these conditions, brazilin and protosappanin B were separated with a sample‐to‐sample time less than 13 min and detection limits of 0.28 μg/mL and 0.15 μg/mL, respectively. The applicability of the developed method was demonstrated by the detection of brazilin and protosappanin in methanol extract of sappan lignum.     

Synthesis in the diazasteroid group. III . Syntheses of the 8,16- and 8,17-diazasteroid systems

By using 3-pyrrolidone derivatives as a source of the D ring, the following five diazasteroids were synthesized: 8,16-diaza-2,3-dimethoxy-15,15,16-trimethylgona-1,3,5(10),13-tetraen-12-one (VII), 8,16-diaza-2,3-dimethoxy-16-acetylgona-1,3,5(10),13-tetraen-12-one (X), 8,17-diaza-2,3-dimethoxy-17-acetylgona-1,3,5(10),13-tetracn-12-one (XI), 8,16-diaza-16-acetylgona-1,3,5(10), 13-tetraen-12-one (XII), and 8,17-diaza-17-acetylgona-1,3,5(10),13-tetraen-12-one (XIII).     

Syntheses and spectroscopic studies on group IIB metal 1,4-benzodiazepine complexes

Summary The preparation and characterization of some zinc(II) and cadmium(II) halide complexes with 1,3-dihydro-7-nitro-5-phenyl-2H-1,4-benzodiazepin-2-one and 7-chloro-l-methyl-5-phenyl-3H-1,4-benzodiazepin-2-one are reported. The complexes have been studied by means of magnetic susceptibility measurements, i.r. and far-i.r. spectra and conductivity measurements. Assignments for metalligand and metal-halide modes have been made. The evidence suggests that the complexes, which contain 1 : 1.5, 1 : 1, 1 : 2 and 1 : 4 metal : ligand stoichiometric ratios, have a pseudotetrahedral symmetry, with the exception of Zn(Mog)₄Br₂ ·₂H₂O which is octahedral.     

Syntheses of group 7 metal carbonyl complexes with a stable N-heterocyclic chlorosilylene

Two structurally characterized manganese [L(2)Mn(CO)(4)](+)[Mn(CO)(5)](-) (1) and rhenium [L(3)Re(CO)(3)](+)[ReCO)(5)](-) (2) silylene complexes were prepared in one pot syntheses by reacting 1 equivalent of Mn(2)(CO)(10) with 2 equivalents of stable N-heterocyclic chlorosilylene L {L = PhC(NtBu)(2)SiCl} and 1 equivalent of Re(2)(CO)(10) with 3 equivalents of L in toluene at room temperature. Both complexes 1 and 2 were characterized by single-crystal X-ray structural analysis, NMR and IR spectroscopy, EI-MS spectrometry, and elemental analysis.     

Synthesis in the diazasteroid group. XII Syntheses of the 10,17-diazasteroid and 10-aza-17-thiasteroid systems

Upon desulfurization with Raney Ni, the condensed heterocycles 2a,b prepared by cyclization from β-ketosulfoxides 1a,b gave β-ketones 3a,b , which were condensed with 2-carbethoxymethyl-piperidine 4 to afford the 10,17-diazasteroid 6 and the 10-aza-17-thiasteroid 7 , respectively.     

Syntheses of N-silylformamidines by the hydrosilylation of carbodiimides

The hydrosilylation of carbodiimides was found to proceed at higher temperatures in the presence of catalytic amounts of palladium chloride or tris-(triphenylphosphine)chlororhodium to afford N-silylformamidines in high yield. These were found to be good precursors to formamidines and N-acetyl-formamidines.     

Syntheses and structures of methyltris(pyrazolyl)silane complexes of the group 6 metals

The methyltris(3,5-dimethylpyrazolyl)silane ligand, TpsMe2, was readily prepared by the metathesis reaction of methyltrichlorosilane with 3 equiv of lithium 3,5-dimethylpyrazolate. The octahedral tricarbonyl complexes (TpsMe2)M(CO)3 were synthesized either by ligand exchange with the labile nitrile adducts M(CO)3(NCR)3 (M = Cr, Mo, R = Me; M = W, R = Et) or thermally by direct substitution on the hexacarbonyls M(CO)6 (M = Cr, Mo). The three new complexes were characterized by a combination of analytical and spectroscopic techniques, including electrospray ionization mass spectrometry and single-crystal X-ray diffraction. They are all isostructural and display in the solid state the expected distorted octahedral geometries with facially coordinated tris(pyrazolyl)silane ligands. Crystallographic data were used to calculate the ligand cone angles (251-264 degrees) in (TpsMe2)M(CO)3 and also to estimate a value of 1.59 A for the covalent radius of octahedral W(0).     

Syntheses, X-ray structures and AACVD studies of group 11 ditelluroimidodiphosphinate complexes

Reactions of Na(tmeda)[N((i)Pr(2)PTe)(2)] with CuCl, AgI or AuCl (in the presence of PPh(3)) in THF produced the coinage metal ditelluroimidodiphosphinate complexes {Cu[N((i)Pr(2)PTe)(2)]}(3), (5), {Ag[N((i)Pr(2)PTe)(2)]}(6) (6) and Au(PPh(3))[N((i)Pr(2)PTe)(2)] (7), respectively. Complexes 5, 6 and 7 were characterized in the solid state by X-ray crystallography. Complex 5 is trimeric and exhibits a highly distorted Cu(3)Te(3) ring. In contrast, the Ag(I) complex 6 is a hexamer, and forms a twelve-membered Ag(6)Te(6) ring. The replacement of the (i)Pr groups on phosphorus by Ph results in an intriguing structural change to a tetramer with a boat-shaped Ag(4)Te(4) ring in {Ag[N(Ph(2)PTe)(2)}(4).2THF (8). The gold(I) complex 7 is monomeric. Aerosol-assisted chemical vapour deposition (AACVD) of compounds 5, 6 and 7 yields CuTe, Ag(7)Te(4), AuTe(2) and Au films, respectively. The films were grown at temperatures of 300-500 degrees C and characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive analysis of X-rays (EDAX).     

Syntheses of methylketones of peptides with C-terminal optically active lysine: Removal of the benzyloxycarbonyl group

Summary Several methods for the removal of the benzyloxycarbonyl group fromZ-Ala-Phe-Lys(Z)-CH₃ have been tested. Only catalytic hydrogenation in acetic acid gives the desired products with satisfactory yield and without racemization at C- of lysine.

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Synthesen von Methylketonen von Peptiden mit C-terminalem optisch aktivem Lysin: Entfernung der Benzyloxycarbonylschutzgruppe

Zusammenfassung Verschiedene Methoden zur Entfernung der Benzyloxycarbonylschutzgruppe vonZ-Ala-Phe-Lys(Z)-CH₃ wurden untersucht. Nur durch katalytische Hydrierung Essigsäure können die gewünschten Produkte in zufriedenstellender Ausbeute und ohne Racemisierung am C- des Lysins erhalten werden.

     

Asymmetric Syntheses Aided by Biocatalysts

This article summarizes the achievements of the authors‘ group in the area of biocatalyst-catalyzed organic reactions in recent 10 years. A strain of Geotrichum sp. obtained by screeninu is capable of stereoselectlvely reducing a number of carbonyl compounds. In many cases, the stermghemistry is complementary with that obtained by baker‘ s yeast. Therefore, this microorganism provides a useful pathway to the preparation of alcohol eompounds with specific configurations. On the other hand, a nmmber of plant sourees have been screened for oxynitrilases and the hydrocyanation reactions of various arylcarboxalde-hydes have been investigated.A“micro-aqueous reaction system“ was invented,by which a serles of novel optically active cyanohydrins were prepared.On this hasis,a high through-put comtimasous reaction system has been designed.This paper also deseribes examples of the syntheses of bio-active compounds by using the optieally active compounds obtained from the above mentioned catalytic reactions as precursors.     

多芳胺选择性甲酰化合成多芳胺基苯甲醛

多芳胺取代芳香醛是合成有机电致发光材料 [1] 、照相底片光感受器材料 [2 ,3] 和传输载体材料 [4 ] 等重要材料的中间体 .将多芳胺引入卟吩分子中形成的多芳胺取代卟吩具有特殊红色荧光性能 ,可望发展成为红色电致发光材料 [5] .多芳胺取代卟吩的合成中需要对多芳胺的一个芳基选择性引入一个醛基 .单芳基叔胺的芳基甲酰化 ,可以通过 Vilsmeier- Haack反应 [6 ] 由芳基叔胺与 DMF和 POCl3作用实现 .对于多芳胺类化合物 ,也可以由 Vilsmeier- Haack反应使多芳胺类化合物分子中的芳基完全甲酰化 [7] .但是对多芳胺类化合物分子 ,尤其是对…     

Vibrational spectroscopic study of brazilin and brazilein,the main constituents of brazilwood from Brazil

In this work, the vibrational spectra (FT-Raman and infrared spectra) of brazilin, the major component of brazilwood Caesalpinia echinata (from Bahia, Brazil), and brazilein, the oxidised pigment, are investigated. The FT-Raman spectra of the compounds show different patterns in the carbonyl stretching region, where brazilein presents a Raman feature at 1697 cm⁻¹ that is tentatively assigned to a coupled vibrational mode described by CO and aromatic CC stretching. Infrared measurements are used to support this assignment. The spectral region between 1700 and 1500 cm⁻¹ is also proposed as a fingerprint for brazilin and brazilein. Comparisons with some quinones and polyalcohols as parent molecules and other deep red resin pigments such as “dragon’s blood” are undertaken to assist the vibrational assignment. As a test of the spectroscopic protocol for the identification of these pigments in natural brazilwoods, an 80-year-old archival specimen of Caesalpinia echinata was analysed non-destructively and the feature of brazilein shown from the Raman spectrum.     

Syntheses and crystal structures of group 6 metal complexes containing allyl and cyanotrihydroborate groups

Compounds M(η³-C₃H₅)(CO)₂(NCCH₃)₂(NCBH₃) and [N(CH₃)₄]₂[M(η³-C₃H₅)(CO)₂(NCBH₃)₃] (M = Mo, W) were prepared and structurally characterized. In the solid state, the allyl group orients its open face to the two carbonyl groups producing an endo form in the above compounds. In solution, an exo form coexists with an endo form in compound Mo(η³-C₃H₅)(CO)₂(NCCH₃)₂(NCBH₃). The cyanotrihydroborate ligand bonds to the metal through a nitrogen atom. Both of the IR and the 11B NMR spectroscopic data suggest the negative charge of the cyanotrihydroborate ligand on the complex is almost localized on the BH₃ and this negative charge only has small effect on the metal-nitrogen interaction.