摘要:

AbstractLanthanide compounds have been attracting much attention in organic synthesis. Chiral Ln‐substituted BINOL have been widely studied in several asymmetric organic reactions. LnCl3and Ln(OTf)3have been expected to serve as Lewis acids and have been applied to many important synthetic reactions in a one‐pot manner. Ln(O‐i‐Pr)3exhibits some basic characters, which also can be utilized in some special organic transformation. This article deals with some lanthanides(III) complexes promoted organic reactions, which we have recently de

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200502

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe first crystal structural report of a AgDTC complex (DTC = dialkyldithiocarbamate, R =n‐butyl) presented in this paper shows that it is a hexanuclear species. The structural arrangement for the DDP (dialkyldithiophosphate) ligands is different from that of Cu6(DDP)6, but is the same as that of Ag6‐[SSP(O‐i

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200503

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractA novel two‐dimensional network dibenzo‐18‐crown‐6 (DB18‐C6) complex: [Na (DB18‐C‐6) (H2O)2] [Na (DB18‐C‐6) (SCN)2] has been isolated and characterized by elemental, IR and X‐ray diffraction analysis. The crystal structure belongs to monoclinic, space groupP21/cwith cell dimensionsa =1.06178(7),b= 1.40243(8),c= 3.03496(19) nm, β = 90.4220(10)°,V= 4.5292(5) nm3, Z=4,Dcalcd=1.351 g/ cm3,F(000) = 1936,R1= 0.0369,wR2= 0.0821. The most interesting feature in this structure is that complex cation and complex anion form a two‐dimensional network via τ‐τ stacking interactions, hydrogen bonds and

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200504

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractA general and practical procedure for the syntheses of 3,4‐di‐hydropyrimidine‐2(1H)‐thiones by a one‐pot condensation of aldehyde, β‐ketoester or β‐diketone and thiourea using La‐(OTf)3as the catalyst is described. Mild reaction conditions, excellent yields as well as the environmentally friendly character of La(OTf)3make it an important alternative to the classic acid‐catalyzed B

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200505

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractWith insulin methanol‐water, and the ion‐pairing agent, hydrochloric acid and trifluroacetic acid (TFA), the character of the first plateau (FP) on the elution curve of frontal analysis in reversed phase liquid chromatography (RPLC) was investigated by on‐line UV‐spectrometry and identified with nuclear magnetic resonance (NMR) spectrometry and mass spectrometry. The profile of the FP is the same as that of a usual elution curve of methanol in frontal analysis (FA). When the insulin concentration was limited to a certain range, the height of the FP was found to be proportional to the insulin concentration in mobile phase and its length companying to shorten. The FP profile on the intersection of two tangents reflects the components of the microstructure in the depth direction of the bonded stationary phase layer and the desorption dynamics of the displaced components. The displaced methanol was quantitatively determined by NMR and on‐line UV spectrometries.TFA with high UV absorbance can not be used as an ion‐pairing agent for the investigation of the FP in RPLC, but it can be used as a good marker to investigate the complicated transfer process of components in the stationary phase in RPLC. A stoichiometric displacement process between solute and solvent was proved to be valid in both usual and FA in RPLC. From the point of view of dynamics of mass transfer, the solutes can only contact to the surface of stationary phase in usual RPLC, while solute can penetrate into it in FA of RPLC. The solvation of insulin in methanol and water solution as an example indicating the usage of the FP in the FA was also investigated in

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200506

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractAn automated biomolecular interaction analysis instrument (BI‐Acore) based on surface plasmon resonance (SPR) has been used to determine human immunoglobulin G (IgG) in real time. Polyclonal and‐human IgG antibody was covalently immobilized to a carboxymethyldextran‐modified gold film surface. The samples of human IgG prepared in HBS buffer were poured over the immobilized surface. The signal amplification antibody was applied to amplify the response signal. After each measurement, the surface was regenerated with 0.1 mol/L H3PO4. The assay was rapid, requiring only 30 min for antibody immobilization and 20 min for each subsequent process of immune binding, antibody amplification and regeneration. The antibody immobilized surface had good response to human IgG in the range of 0.12–60 nmol/L with a detection limit of 60 pmol/L. The same antibody immobilized surface could be used for more than 110 cycles of binding, amplification and regeneration. The results demonstrate that the sensitivity, specificity and reproducibility of amplified immunoassay using real‐time BIA technology are sat

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200507

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe bridged tri‐imidazoliums 3 · 3X−— 5 · 3X−(X−= PF6−, Br−, I−) and bis‐imidazoliums 6 × 2PF6−were synthesized byN‐quaternization of imidazole derivative 1 in acetonitrile under reflux. UV spectroscopic titration experiments showed that the halide salts and hexafluorophosphate salts of these imidazoliums exhibited good recognition toward anions in water and in ac

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200508

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractFourteen new di‐n‐butyltin(IV) complexes of hydroxamic acids of the formula Bu2SnL2HL = hydroxamic acids) were synthesized by the reaction of Bu2SnO and hydroxamic acids in dry toluene and ethanol media. The compounds were characterized by elemental analyses, molecular weight, IR and1H NMR spectroscopy. The results indicate thatn‐Bu2SnL2have distortedtrans‐octahedral structure. The antitumor activityin vitroagainst human A‐549 tumor cells and P388 leukemia was presented, and their structure‐activity relationship wa

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200509

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractThe interaction of pinacyanol chloride (PC) with nucleic acids has been investigated by a series of experiments. Extensive hypochromism, appreciable peak shifts, isosbestic points and new peaks of the product of binding to nucleic acids in the spectra were observed. They showed that the interaction between PC and nucleic adds occurred. The results from absorption spectra of DNA, DNA melting, electrophoresis and fluorescence polarization studies have indicated that PC binds to DNA in nonintercalative way. Consistent with the nonintercalation, the studies of fluorescence titration and absorption titration specified that the binding of PC to nucleic acids occurred by an outside stacking binding, in which nucleic acids served for acting templates. The fact that the new absorption peaks of bound PC atca. 485 nm are just close to the absorption bands of H‐aggregate of PC at high concentrations without DNA further supports the outside stacking binding mode. In addition, other evidence indicated that the interaction between PC and nucleic acids is not purely electrostati

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200510

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY

摘要:

AbstractA novel approach of sequence pattern correlation has been applied to predict an expected amino acid sequence from CID ESI‐MS spectra. The proposed approach deduces sequence patterns with no help from known protein database such that it is useful to identify an unknown peptide or new protein. The algorithm applies a cross‐correlation to match an experimental CID spectrum with predicted sequence pattern generated from fragmentation information. The fragmentation knowledge of both y‐series and other non y‐series are utilized to generate the predicted sequence patterns. In contrast to the normalde novoapproach, the proposed approach is insensitive to mass tolerance and non‐susceptive to spectral integrality with no need for selection of a start

ISSN:1001-604X    

DOI:10.1002/cjoc.20020200511

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:2002

数据来源: WILEY