1,720,976 research outputs found
A convergent regiospecific synthesis of zirconium enolates
No full textalpha-Lithiated phenylsulphonyloxiranes insert into alkenylzirconocene chlorides with loss of phenylsulphinate to give zirconyloxiranes which smoothly rearrange by either alpha- or beta- C-O cleavage to afford regiodefined zirconium enolates which may be further elaborated
Insertion of metallated epoxides into zirconacycles
No full textMetallated epoxides (epoxysilanes, epoxynitriles, epoxystyrene) insert efficiently into zirconacycles via a 1,2-metallate rearrangement to form intermediates which eliminate Cp2Zr(R)O- to afford substituted alkenes
Insertion of metallated epoxynitriles into organozirconocene chlorides. A convergent synthesis of 2-cyano-1,3-dienes
No full textLithiated epoxynitriles insert efficiently into alkenylzirconocene chlorides via a 1,2-metallate rearrangement to form intermediates which eliminate Cp2Zr(Cl)O- to afford substituted 2-cyano-1,3-dienes
Carbenoid insertion into alkenylzirconocenes - a convergent synthesis of functionalised allylmetallics
No full textInsertion of lithium alkylcarbenoids RC(A)LiX, A= CN, P(O)(OEt)(2), SO2Ph, OMe into alkenylzirconocene chlorides derived by hydrozirconation of terminal alkynes affords functionalised allylzirconium reagents which may be further elaborated
Synthesis and characterisation of an open-cage fullerene encapsulating hydrogen fluoride
No full textThe first encapsulation of hydrogen fluoride in an open-cage fullerene is reported. Solution and solid-state NMR spectra of the novel open-cage endofullerene are described
Corrigendum to Palladium-catalysed three component synthesis of ?, ?-unsaturated amidines and imidates [Tetrahedron Lett. 45 (2004) 6991]
No full textPalladium-catalysed three component coupling of an alkenylbromide, isonitrile and an amine or alkoxide/phenoxide affords ?, ?-unsaturated-amidines and -imidates
Synthesis of phosphinines and phosphinanes using zirconium chemistry
No full textRing expansion of readily available zirconacyclopentadienes or zirconacyclopentanes by insertion of chloro(trimethylsilyl)rnethyllithium followed by metathesis with phosphorous trichloride provides a novel route to lambda(3)-phosphinines (phosphabenzenes) or phosphinanes
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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