29017-36-5Relevant academic research and scientific papers
Kinetic study on denomination of vic-dibromides with trivalent phosphorus compounds
Yasui, Shinro
, p. 217 - 222 (2001)
Various types of trivalent phosphorus compounds (I) brought about reductive debromination of vic-dibromides (2) to afford olefins. The reaction was accelerated by either electron-releasing substituents on the phosphorus of 1 or electron-with-drawing substituants on the α-carbon of 2. The substituent effects, along with the stereochemistry of the reaction, are consistent with an E1CB-like mechanism for the elimination of the two bromine atoms. That is, 1 initially undergoes nucleophilic attack upon a bromine of 2. At the transition state, a fractional positive charge is developed on the phosphorus of 1 and a fractional negative charge on the carbon of 2. This mechanism suggests the importance of an electronic character of the vic-dibromide in determining the relative ease of bromophilicity, carbophilicity, and basicity of the phosphorus of a trivalent phosphorus compound in a reaction with the dibromide. α 2001 John Wiley & Sons, Inc.
Elimination Reactions of Stilbene Dibromides. Dehydrobromination by Acetate, Cyanide or Chloride Ions in Dimethylformamide
Avraamides, James,Parker, Alan J.
, p. 1705 - 1717 (2007/10/02)
Rates of dehydrobromination of a series of 4-nitro- and methoxystilbene dibromides by means of acetate, cyanide or chloride ions in dimethylformamide have been measured.A product analysis was performed which indicated a strong preference for anti elimination.Probable transition state structures utilized by each of the three nucleophiles are described.Attack by the base may be at either β-hydrogen (E 2H) or Cα(E2C).The slowest reaction in with chloride ion, which also gives the highest anti/syn elimination product ratio.
