Zobrazeno 1 - 10
of 81
pro vyhledávání: '"Lothar Knothe"'
Publikováno v:
European Journal of Organic Chemistry. 2007:4867-4880
Attempts to synthesize the long soughtafter tris-π-homobenzene cis,cis,cis-2,5,8-cyclononatriene-1,4,7-trione, via the newly prepared cyclononane-1,4,7-trione (C9H6O3), through base-catalysed threefold HBr elimination from an efficiently prepared an
Autor:
Joern Tonne, Lothar Knothe, Thomas Mathew, Horst Prinzbach, Dieter Hunkler, Manfred Keller, C. Grund, Gottfried Sedelmeier
Publikováno v:
European Journal of Organic Chemistry. 2007:2133-2146
In two specifically constructed rigid, proximate, “face-to-face” benzo/pyridazino systems (shortest π,π distances ca. 3 A) photoequilibration with the photo[6+6]cycloadducts has been established by 254-nm irradiation (ratios ca. 2:1). The failu
Autor:
Andreas Weiler, Alois Haas, Horst Prinzbach, Emmerich Sackers, Dieter Hunkler, Jürgen Wörth, Torsten Voss, Lothar Knothe, Peter Landenberger, Fabian Wahl, Max Lieb
Publikováno v:
Chemistry - A European Journal. 12:6255-6267
"One-pot" substitution of the twenty hydrogen atoms in pentagonal dodecahedrane (C(20)H(20)) by OH, F, Cl, and Br atoms is explored. Electrophilic insertion of oxygen atoms with DMDO and TFMDO as oxidizing reagents ended, far off the desired C(20)(OH
Autor:
Fushun Yang, Kai Exner, Markus Kegel, Birgit Großmann, Horst Prinzbach, Markus Heizmann, Manfred Keller, Jürgen Heinze, Lothar Knothe
Publikováno v:
European Journal of Organic Chemistry. 2005:1311-1331
In the pursuit of novel bishomoconjugated (σ-bishomoaromatic) 4N/7(6)e bonding motifs, (bisseco)pagodane/isopagodane and dodecahedrane-like, caged, proximate-parallel bishydrazines have been designed as suitable host skeletons. The derived radical c
Autor:
Markus Vögtle, Fushun Yang, Horst Prinzbach, Lothar Knothe, Eberhard Beckmann, Oliver Cullmann, Manfred Keller, Markus Kegel, Kai Exner, Nicolaus Bahr
Publikováno v:
European Journal of Organic Chemistry. 2003:4248-4264
Synthetic details are presented for a series of more or less rigid, “parallel-in-plane” preoriented bis(diazenes), with N=N/N=N distances (d) of 3.3−2.9 A and interorbital angles (ψ) of 142−164° (X-ray crystal structures). DFT calculations
Autor:
Thomas Oßwald, Lothar Knothe, Jürgen Wörth, Dieter Hunkler, Jens Reinbold, Torsten Voss, Andreas Weiler, Bernd von Issendorff, Klaus Weber, Nina Morgner, Horst Prinzbach, Emmerich Sackers, Frank Sommer
Publikováno v:
Chemistry - A European Journal. 8:509-524
The highly pyramidal, highly strained C20H14 1,4,16-dodecahedratriene (4) and C20H12 1,4,10(14),16-dodecahedratetraene (5) are cage olefins with an intriguing “inner life”. For 5 DFT calculations give information about the energetic and geometric
Autor:
Georg Gescheidt, Dmytro Neschchadin, Lothar Knothe, G. K. Surya Prakash, Martin Bertau, Jens Reinbold, George A. Olah, Jürgen Heinze, Torsten Voss, Bernhard Mayer, Dieter Hunkler, Horst Prinzbach, Hans-Dieter Martin
Publikováno v:
Helvetica Chimica Acta. 84:1518-1560
Secodecahedradiene 2a, featuring very proximate, perfectly syn-periplanar and significantly pyramidalized C=C bonds, was synthesized as testing object for in-plane(σ)-homoconjugational electron delocalization, starting from the available pagodane 15
Autor:
Fabian Wahl, Jens Reinbold, Jürgen Wörth, Horst Prinzbach, Markus Wollenweber, Rolf Pinkos, Markus Etzkorn, C. Grund, Johann-Peter Melder, Torsten Voss, Manfred Keller, Dieter Hunkler, Lothar Knothe
Publikováno v:
European Journal of Organic Chemistry. 2000:3855-3886
The established route to the [1.1.1.1]/[2.2.1.1]pagodanes (1, 2) has been applied to the construction of the homologous [2.2.2.2] and [2.1.1.1] skeletons (3, 7). Application of this synthetic scheme to the iso[1.1.1.1]/iso[2.2.1.1]/iso[2.2.2.2] struc
Autor:
Hans Fritz, Meinrad Lugan, Gerhard Fischer, Dieter Hunkler, Kai Exner, Horst Prinzbach, Manfred Keller, Lothar Knothe
Publikováno v:
European Journal of Organic Chemistry. 2000:787-806
Of two very proximate syn-periplanar bisdiazenes (1,2) mono-, di-, tri- and tetra-N-oxides were prepared, representing six combinations of the individual NN/NNO/ONNO chromophores. According to DFT calculations (B3LYP/6-31G*), [2+2]photocycloaddition
Autor:
Meinrad Lugan, Horst Prinzbach, Dieter Hunkler, Nikolaus Bahr, Eberhard Beckmann, Kai Exner, Lothar Knothe, Gerhard Fischer, Manfred Keller, Fushun Yang, G. Rihs
Publikováno v:
European Journal of Organic Chemistry. 2000:763-785
Rigid NN/NN (diazene/diazene) systems (F) consisting of more or less alkylated DBH and DBO chromophoric units (1, 2, X-ray structures), with very short π,π distances [d = 2.849 (1a, av.), 2.822 A (2)] and almost perfect syn-periplanar π,π alignme