106913-99-9Relevant articles and documents
C2-symmetric bicyclo[3.3.1]nonadiene as a chiral ligand for rhodium-catalyzed asymmetric arylation of N-(4-nitrobenzenesulfonyl)arylimines
Otomaru, Yusuke,Tokunaga, Norihito,Shintani, Ryo,Hayashi, Tamio
, p. 307 - 310 (2007/10/03)
(Chemical Equation Presented) Asymmetric synthesis of diarylmethylamines with high enantioselectivity (95-99percent ee) was realized by use of a new C 2-symmetric diene ligand, (1R,5R)-2,6-diphenylbicyclo[3.3.1]nona-2,6- diene (Ph-bnd*), for th
Synthesis and Structure of Phenyl-Substituted Bicyclononenes
Quast, Helmut,Knoll, Katja,Peters, Eva-Maria,Peters, Karl,Schnering, Hans Georg von
, p. 777 - 784 (2007/10/02)
Addition of one mole of phenyllithium to bicyclononane-2,6-dione (5) affords the hydroxy ketone 6 besides small amounts of the known diol 7.Dehydration of this mixture by sulfuric acid in acetic acid yields the unsaturated ketone 8 and the diene 1 which are separated by chromatography.Wolff-Kishner reduction of 8 furnished the hydrocarbon 2.In the same way, the known ketones exo- and endo-10 are converted into 4.The preferential formation of the less stable endo-10 is interpreted in terms of the relative stability of the conformations required in the intramolecular aldol reaction of diketone 9.The conformations of 4, 8, exo- and endo-10 are determined by X-ray diffraction analyses.Vicinal proton coupling constants are calculated from torsional anlges and compared to those determined in solutions by high-field NMR spectroscopy.Key Words: Bicyclonon-2-ene, phenyl-substituted derivatives of / Conformation of bicyclonon-2-enes
SYNTHESIS AND DEGENERATE COPE REARRANGEMENT OF 2,6-DIPHENYLBARBARALANE
Quast, H.,Geissler, E,Mayer, A.,Jackman, L. M.,Colson, K. L.
, p. 1805 - 1814 (2007/10/02)
The oxygen-sensitive 2,6-diphenylbarbaralanes 15 and 16 are synthesized from bicyclononane-2,6-dione (9) via dibromide 14 in four steps with 46 and 54percent overall yield, respectively.Crystalline 2,6-diphenylbarbaralane (15) is yellow at room temperature and decolourizes reversibly on cooling.Accordingly, the UV spectrum of trans-decalin solutions of 15 changes reversibly in the temperature range 295-450 deg K.The bromodiphenylbarbaralane 16 is shown to exist as a single valence tautomer.The 13C chemical shifts of 16 serve as estimates of the analogous shifts in the non-exchanging valence tautomer of 2,6-diphenylbarbaralane (15) itself.The barrier for the degenerate Cope rearrangement of 15 in dichloromethane has been determined from 13C-NMR line width measurements in the temperature range of 169-233 deg K to be ΔG++200 = 21.6 kJ mol-1.Hence phenyl substituents at the termini of the allylic parts of barbaralane accelerate the degenerate Cope rearrangement somewhat more than cyano groups.
