Treatment of β-naphthil dihydrazone, 1, with silver oxide yields di(β-naphthyl)acetylene, 2, which undergoes Diels-Alder cycloaddition with tetra(β-naphthyl)cyclopentadienone, 4, to give hexa(β-naphthyl)benzene, 5, upon decarbonylation. Molecules 1, 2 and 4 have been characterised by X-ray crystallography, but hexa(β-naphthyl)benzene exhibits rotational disorder of the peripheral substituents. Nevertheless, calculations at the density functional level reveal the favoured structure of 5 to be a molecular propeller, in which the eight possible rotamers are essentially iso-energetic.
View Article and Find Full Text PDFReaction of [PtCl(2)(COD)] and [PtI(2)(COD)] with 2,7-di-tert-butyl-5-diphenylboryl-4-diphenylphosphino-9,9-dimethylthioxanthene (TXPB) afforded square planar [PtCl(2)(TXPB)] (1B) and [PtI(2)(TXPB)] (4B), both of which were crystallographically characterized. Single-crystal X-ray quality crystals were also obtained for [PdCl(2)(TXPB)] (2B; Emslie et al., Organometallics, 2008, 27, 5317) as 2B·2CH(2)Cl(2) and solvent-free 2B.
View Article and Find Full Text PDFA new approach for preparing (99m)Tc-labelled compounds in high effective specific activity was developed by utilizing a novel fluorous ligand capture (FLC) agent and a chemoselective filtration strategy. This paradigm eliminates the need to use HPLC to obtain technetium(I) based molecular imaging probes free from residual precursor.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
March 2008
The title compound, C(11)H(9)N(3)OS, was prepared to investigate the coordination chemistry of thio-phene-containing ligands as precursors to inter-esting metallopolymers. The mol-ecule is nearly planar. The angle between the thio-phene and pyridine rings is 8.
View Article and Find Full Text PDFActa Crystallogr Sect E Struct Rep Online
January 2008
The title compound, C(16)H(12)N(2)O(2)S, was prepared by a Neigishi cross-coupling reaction to investigate the coordination chemistry of thio-phene-containing ligands. In the mol-ecule, the pyridine rings are twisted from the thio-phene ring by 20.6 (1) and 4.
View Article and Find Full Text PDFWith the development of targeted therapeutics, especially for small-molecule inhibitors, it is important to understand whether the observed in vivo efficacy correlates with the modulation of desired/intended target in vivo. We have developed a small-molecule inhibitor of all three vascular endothelial growth factor (VEGF) receptors (VEGFR), platelet-derived growth factor receptor, and c-Kit tyrosine kinases, pazopanib (GW786034), which selectively inhibits VEGF-induced endothelial cell proliferation. It has good oral exposure and inhibits angiogenesis and tumor growth in mice.
View Article and Find Full Text PDFMicrowave heating was used to prepare eta5-rhenium carborane complexes in aqueous reaction media. For carboranes bearing sterically demanding substituents, isomerization of the cage from 3,1,2 to 2,1,8 derivatives occurred concomitantly with complexation. Microwave heating was equally effective at the tracer level using technetium-99m, affording access to a new class of synthons for designing novel molecular imaging agents.
View Article and Find Full Text PDF1-Phenyl-3,3-biphenyleneallene (2), the base-catalyzed rearrangement product of 9-phenylethynylfluorene (1) yields a yellow, head-to-tail dimer 6 that, upon gentle warming, is converted to the red tail-to-tail isomer trans-3,4-diphenyl-1,2-bis(fluorenylidene)cyclobutane (7), in which the two fluorenylidene moieties severely overlap. The helical sense of the fluorenylidene moieties in 7 matches that of the phenyl substituents, and the interplanar angle between the fluorenylidene moieties is 41 degrees . At 80 degrees C, 6 isomerizes to orange cis-3,4-diphenyl-1,2-bis(fluorenylidene)cyclobutane (8), which at 110 degrees C is converted to orange trans diastereomer 9, whereby the helicity of the overlapping fluorenylidene moieties is reversed from that in 7 such that they are aligned with the ring hydrogen atoms, and the interplanar angle between the fluorenylidene moieties is now 60 degrees .
View Article and Find Full Text PDFThe attempted Diels-Alder reaction between 9-phenylethynylfluorene and tetracyclone yields instead three products resulting from the dimerization of the isomeric allene. The major product is 8,16-diphenyl-diindeno[1,2,3-de:1',2',3'-mn]naphthacene, in which each terminal ring is derived from a fluorenyl unit; aerial oxidation then yields a peroxide. A dihydronaphthacene bearing fluorenyl moieties spiro-bonded at the C(5) and C(11) positions was also identified.
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