Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1434-193X
    Keywords: Indiumallyl compounds ; Vinylcyclopropanes ; α,β-Unsaturated carbonyl compounds ; Diastereoselectivity ; Dibenzylideneacetone ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Allylindium reagents, prepared from excess allylic halide (Br or I) and indium metal, react with α,β-unsaturated ketones and aldehydes to give, after aerobic acidic workup, homoallyl-substituted vinylcyclopropanes. This process was explored and developed after a chance discovery arising from a side reaction in an attempted Pd-catalysed process. The structure of the cyclopropane arising from the reaction of bis(p-chlorobenzylidine)acetone was confirmed by X-ray crystallography. Whilst bis-α,β-unsaturated ketones give rise to a single homoallylcyclopropane species, α,β-unsaturated ketones and aldehydes give diastereomeric mixtures whose relative stereochemistry were assigned by NOE experiments. Crotylindium reagents react with good to perfect regioselectivity to afford tetrasubstituted cyclopropanes but prenylindium reagents fail to generate the analogous pentasubstituted rings.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1434-193X
    Keywords: Indium ; Vinylcyclopropanes ; Ring closing metathesis ; Norcarenes ; Kinetic diastereoselection ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---Homoallyl-substituted vinyl cyclopropanes 1a-c, which are readily prepared by reaction of allylindium reagents with α,β-unsaturated ketones and aldehydes, undergo Ru-catalysed RCM reactions with Grubbs catalyst to give [4.1.0]bicyclooct-2-ene (norcarene) type bicyclic products. Noncyclisable ‘trans’ homoallyl-substituted vinyl cyclopropanes 1b and 1c are separated from their ‘cis’ diastereomers by RCM to 5b and 5c - but only with moderate efficiency due to a competing homo-cross metathesis (‘dimerisation’) to give 7b and 7c, respectively. However, the four diastereomers of the (homoallyl)distyrylcyclopropane 14a obtained from indium-mediated reaction of dibenzylideneacetone and crotyl bromide undergo remarkable kinetic diastereoselection in their RCM reactions to give a 4,7-dimethyl[4.1.0]bicyclohept-2-ene-type product 15a. This process allows recovery of a single diastereomer (〉 95%) of 14a without dimerisation being a significant side reaction. Furthermore, the RCM product 15a is obtained rich in one diastereomer (ca. 90%). The kinetic diastereoselection and lack of dimerisation can be rationalised by considering developing transannular interactions and a pseudo-A1,3 strain model.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1434-1948
    Keywords: Coordination modes ; Cyclophanes ; Macrocycles ; Sandwich complexes ; Solid-state structures ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A novel mode of containment for metal ions which participate in longer-range interactions with aryl rings (≥ 2.5 Å) is demonstrated in the preorganized cylindrical host 1. Three equatorial sulfur atoms in 1 hold metals in a trigonal planar ligand field between two apical benzene centroids at an M-Ar distance of about 3 Å. Evidence of an interaction between the π electrons and the metals is gained by 1H NMR spectroscopy of the complexes, and support for the general description of metal-arene contacts in the 2.5-3.5 Å range as ‘‘bonds’’ is derived from a statistical study of η6-coordination in the solid state. Crystal structures of [Ag(1)]BF4 and [Cu(1)]BF4 confirm the first examples of arene AgI and CuI sandwich complexation and indeed the only structurally characterized CuI-aryl centroid interaction. The two isomeric tris-sulfoxides derived from 1 show less tendency to interact with metals ions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1434-1948
    Keywords: Chirality ; Ruthenium ; Chiral resolution ; Nitrogen heterocycles ; Carbonyl complexes ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A range of chiral building blocks of the type Δ- or Λ-[Ru(pp)2(CO)2]2+ {pp = bidentate ligands bpy (2,2′-bipyridine), phen (1,10-phenanthroline) and Me2bpy (4,4′-dimethyl-2,2′-bipyridine)} have been synthesized, and their enantiomeric purity and absolute configurations determined by CD and NMR studies. Decarbonylation using trimethylamine oxide in the presence of the respective pp ligand at room temperature produced the corresponding tris(bidentate) species [Ru(pp)3]2+ with retention of configuration at the ruthenium(II) centre. A general chromatographic technique for resolution of tris-homoleptic complexes of the type [Ru(pp)3]2+ was investigated, with the absolute configurations of the resolved complexes confirmed by CD studies, and the X-ray structural analyses of Δ-(-)-[Ru(Me2bpy)3]{(-)-O,O′-dibenzoyl-L-tartrate} and Λ-(+)-[Ru(phen)3]{(+)-O,O′-di-4-toluoyl-D-tartrate}. Resolution is also reported for the analogous species containing three potential bridging ligands, [Ru(bpm)3]2+ and [Ru(HAT)3]2+ (bpm = 2,2′-bipyrimidine; HAT = 1,4,5,8,9,12-hexaazatriphenylene). The versatility of the chromatographic procedure was demonstrated by the resolution of a series of bis-heteroleptic complexes [Ru(pp)2(pp′)]2+ {pp′ = dpq (dipyrido[3,2-d:2,3′-f]quinoxaline), dpqc (dipyrido[3,2-a:2,3-d]-6,7,8,9-tetrahydrophenazine), and dppz {dipyrido[3,2-a:2,3′-d]phenazine)}.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0730-2312
    Keywords: cell lines ; clinical correlation ; in vitro data ; polymorphic markers ; lung cancer ; Life Sciences ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The cell line data base described in this paper includes both clinical information about the patients from whom the cell line were derived and information about the in vitro analyses performed of the cell lines. The cell line data base has evolved as a part of a systematic effort by a research group at the NCI since 1976 to generate human cell lines as biological tools to study cancer and other diseases. The cell lines were generated from clinical specimens obtained as part of a series of Institutional Review Board-approved clinical protocols. The preponderance of the data is on lung cancer cell lines, though a broad range of other cancers are represented. A bank of over 300 human cell lines including cancer cell and in some instances autologous B-lymphoblastoid cells from the NCI-VA and NCI-Navy Medical Oncology Branch are reposited at the American Type Culture Collection. The cell lines are available for the research community. The entire data base is available on the American Type Culture Collection Web Site (///http://www.atcc.org/). © 1996 Wiley-Liss, Inc.This article is a US Government work and, as such, is in the public domain in the United States of America.
    Additional Material: 5 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0730-2312
    Keywords: CTCL ; Sezary ; HTLV-I ; HIV ; IL-2 ; Life Sciences ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Efforts at the National Cancer Institute to generate continuous in vitro cultures from patients with mycosis fungoides and the Sezary syndrome, neoplasms with a mature T-helper phenotype, led to the establishment of two cell lines, HUT78 and HUT102. Further characterization of these cell lines led to the identification of the first human retrovirus, HTLV-1, in the HUT102 cells, and the clinical description of the syndrome of HTLV-1 associated acute T-cell leukemia/lymphoma; the serum antibody test to screen for this virus was developed from the serum of the patient from whom the cell line was derived. The HUT78 cell line was pivotal in the identification and characterization of the HIV retrovirus in that a subclone, H9, proved to be permissive for replication of HIV in vitro. Propagation of HIV in vitro in H9 cells allowed for the development of immunological reagents to screen blood supplies for the presence of the virus. Further biologic and molecular studies of these lines have led not only to a better understanding of the underlying diseases but also to the development of rational therapeutic approaches. © 1996 Wiley-Liss, Inc.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0044-8249
    Keywords: Cluster ; Festkörperstrukturen ; Scandium ; Seltenerdmetallverbindungen ; Tellur ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0044-8249
    Keywords: Aluminium ; Festkörperstrukturen ; Mikroporosität ; Phosphor ; Zeolithe ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Supramolecular Structure 11 (1979), S. 563-577 
    ISSN: 0091-7419
    Keywords: plasma membrane ; lectin receptors ; affinity chromatography ; membrane proteins ; hybridoma ; monoclonal antibody ; Life Sciences ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Concanavalin A-binding (Con A)-binding cell surface glycoproteins were isolated, via Con A-affinity chromatography, from Triton X-100-solubilized Chinese hamster ovary (CHO) cell plasma membranes. The Con A binding glycoproteins isolated in this manner displayed a significantly different profile on sodium dodecyl sulfate-polyacrylamide gels than did the Tritonsoluble surface components, which were not retarded by the Con A-Sepharose column. [125I]-Con A overlays of the pooled column fractions displayed on sodium dodecyl sulfate-polyacrylamide gel electro-phoresis (SDS-PAGE) demonstrated that there were virtually no Con A receptors associated with the unretarded peak released by the Con A-Sepharose column, whereas the material which was bound and specifically eluted from the Con A-Sepharose column with the sugar hapten α-methyl-D-mannopyranoside contained at least 15 prominent bands which bound [125I]-Con A.In order to produce monoclonal antibodies against various cell surface Con A receptors, Balb/c mice were immunized with the pooled Con A receptor fraction. Following immunization spleens were excised from the animals and single spleen cell suspensions were fused with mouse myeloma P3/X63-Ag8 cells. Numerous hybridoma clones were subsequently picked on the basis of their ability to secrete antibody which could bind to both live and glutaraldehyde-fixed CHO cells as well as to the Triton-soluble fraction isolated from the CHO plasma membrane fraction. Antibody from two of these clones was able to precipitate a single [125I]-labeled CHO surface component of ∼265,000 daltons.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York, N.Y. : Wiley-Blackwell
    Journal of Supramolecular Structure 6 (1977), S. 559-570 
    ISSN: 0091-7419
    Keywords: rhodopsin ; rod cell membrane ; limited proteolysis ; phosphorylation site ; amino-terminal ; carboxy-terminal ; carbohydrate attachment ; Life Sciences ; Molecular Cell Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: The amino terminus of bovine rhodopsin is blocked and has the sequence x-Met-Asn(CHO)-Gly-Thr-Glu-Gly-Pro-Asn-Phe-Tyr-Val-Pro-Phe-Ser-Asn(CHO)-Lys-Thr-Gly-Val-Val-Arg, where CHO represents sites of carbohydrate attachment. The carboxyl-terminal sequence of rhodopsin is Val-Ser-Lys-Thr-Glu-Thr-Ser-Gln-Val-Ala-Pro-Ala. Upon short-term digestion of rod outer segment (ROS) membranes with thermolysin, opsin (∼ 35,000 daltons) is converted to a membrane-bound fragment O′ (∼ 30,500 daltons) and 2 peptides containing 12 amino acids are released from the carboxyl terminus of rhodopsin into the supernatant. Upon long-term digestion of ROS with thermolysin, opsin and O′ are replaced by the membrane-bound fragments F1 (∼25,000 daltons), and F2 (∼9,500 daltons). When 32P-ROS are digested, F2 carries the 32P. Both O′ and F1 contain the amino-terminal glycopeptide.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...