30810-15-2Relevant articles and documents
Protonated benzene: A case for structural memory effects?
Schroeder, Detlef,Loos, Jessica,Schwarz, Helmut,Thissen, Roland,Dutuit, Odile
, p. 9931 - 9937 (2008/04/18)
Photoionization tandem-mass spectrometry of selectively deuterium labeled precursor molecules is used to probe the structure of protonated benzene which had been questioned in a provocative publication by Mason and co-workers (J. Chem. Soc., Chem. Commun. 1995, 1027). Specifically, we address the intriguing aspect of a postulated delayed hydrogen ring-walk by modulating the internal energy content of mass-selected C6H7-nDn + ions. To this end, ionization of selectively deuterated precursors by tunable synchrotron photons is combined with chemical monitoring of H +/D+ transfer from C6H7-nD n+ to a strong base B. The resulting BH +/BD+ ratios monotonically decrease with increasing internal energy content and, due to the virtue of the regioselective deuterium label incorporations, thereby disprove a delayed hydrogen ring-walk or any other "structural memory effect" in C6H7-nD n+ ions. As a consequence, the experimental studies of Mason et al. were reconsidered using sector-field mass spectrometry. These extensive studies suggest that the previous observations might have been obscured by a combination of isobaric impurities, metastable-ion contributions, and artifact signals.
Condensations of Crotonate Arsonium Ylide with Conjugated Carbonyl Compounds
Moorhoff, Cornelis M.
, p. 126 - 128 (2007/10/03)
Condensations of methyl 4-(triphenylarsoranylidene)-2-butenoate 1a and conjugated carbonyl compounds give 1,3-cyclohexadiene-1-carboxylates and/or acyclic trienes in superior yields compared to the condensations with the phosphonium analogue 1b. However, the reaction of 1a and ethyl 2-cyano-5-methyl-2,4-hexadienoate 7 gave a mixture of two diastereomeric trans-bisvinylcyclopropanecarboxylates 9.
High Pressure Experiments, XI. Reaction of Phosgene with 1,3-Cyclohexadiene at High Pressure
Kurz, Karlheinz,Plieninger, Hans
, p. 3666 - 3668 (2007/10/02)
Phosgene in toluene reacts at 80 deg C/5000 at with 1,3-cyclohexadiene to yield acyl chlorides.Without pressure no reaction is observed.After esterification the compounds 1-5 could be identified.The Diels-Alder adduct 6 was not observed.
