68331-59-9Relevant academic research and scientific papers
Verification of stereospecific dyotropic racemisation of enantiopure d and l-1,2-dibromo-1,2-diphenylethane in non-polar media
Christopher Braddock,Roy, Debjani,Lenoir, Dieter,Moore, Edward,Rzepa, Henry S.,Wu, Judy I-Chia,Von Rague Schleyer, Paul
supporting information, p. 8943 - 8945 (2012/11/13)
The first example of a dyotropic rearrangement of an enantiomerically pure, conformationally unconstrained, vicinal dibromide confirms theoretical predictions: d and l-1,2-dibromo-1,2-diphenylethane racemise stereospecifically in refluxing benzene without crossover to the meso-isomer. An orbital analysis of this six-electron pericyclic process is presented.
1,2-Bis-(trialkylsilyl)ethanes: Synthons for vicinal dications?
Porter, John M.,Xuan, Xiangyang,Blackman, Burchelle,Hsu, Daniel,Fry, Albert J.
, p. 7147 - 7150 (2007/10/03)
Anodic oxidation of 1,2-bis-(trimethylsilyl)-1,2-diphenylethane in methanol affords a 65:35 mixture of 1,2-dimethoxy-1,2-diphenylethane (dl:meso = 10:1 and diphenylacetaldehyde dimethylacetal. The results can be interpreted in terms of a 1,2-diaryl-2-methoxyethyl cation, which can undergo either nucleophilic attack by solvent or rearrangement to a 2,2-diaryl-1-methoxyethyl cation. Experiments testing the generality of the reaction are described.
AFM ON CHEMICALLY REACTING CRYSTALS
Kaupp, Gerd
, p. 153 - 170 (2007/10/02)
A review is given on recent developments of atomic force microscopic (AFM) studies on chemically reacting organic crystals.Three further basic phase transformation mechanisms have been added to the previous five.Both photodimerizations and gas/solid reactions are studied in detail by scanning the surfaces of initial and chemically reacted crystals of anthracenes, thiohydantoines, α- and β-cinnamic acid, and stilbene at different faces, where technically possible.The AFM-features are correlated to known crystal structure data with the aid of semiempirical calculations in part.Thus, detailed molecular mechanisms for the far-reaching well-directed transport phenomena may be derived in most cases and the appearance of the submicroscopic features rationalized.Unimolecular terrace steps of anthracene behave as independent crystal face already.The addition of bromine and chlorine leads to new solid phases directly even though there might be formed mixtures of stereoisomers.If a submicroscopic liquid phase is formed as in the reaction of α-cinnamic acid with chlorine, the surface will be remodelled by the tip and this provides for interesting nanostructures.In many cases there are secondary phase transformations apparently from one form of mixed crystals into another form of mixed crystals either upon continuation of irradiation or just on standing of gas/solid reacted crystals for several hours. - Keywords: atomic force microscopy, solid state photochemistry, gas/solid reaction, basic mechanism, phase transformation, molecular mechanism, unimolecular step, crystal face, crystal structure, nanostructures
Bromination of Alkenes in Acetonitrile. A Rate and Product Study
Bellucci, Giuseppe,Bianchini, Roberto,Chiappe, Cinzia
, p. 3067 - 3073 (2007/10/02)
The reaction of simple alkenes and aryl alkenes with molecular bromine in damp MeCN occurred with solvent incorporation to give 2-bromo-1-(N-acetylamino)alkanes, 2-methyloxazolines, 2-acetoxyalkylamine hydrobromides, and 2-(N-acetylamino) alcohols.These products arose by the transformation of initially formed 2-bromo-1-(N-acetylamino)alkanes obtained by MeCN attack on bromonium or bromocarbonium ions to give nitrilium tribromide salts.These reacted with water to give 2-bromo-1-(N-acetylamino)alkanes.The kinetic profile of the reaction showed a very fast initial reaction of the alkene and Br2 to yield the nitrilium tribromide, followed by a much slower reaction of Br3(1-) with the alkene.The incorporation of MeCN was Markovnikov and stereospecifically anti.The degree to which incorporation of solvent occurred depended upon the alkene structure and the initial reagent concentrations.A rationalization for the observed chemoselectivity and its dependence on the reaction conditions is offered.
