Comparative study of the vicinal functionalization of olefins with 2:1 bromide/bromate and iodide/iodate reagents
作者:Manoj K. Agrawal、Subbarayappa Adimurthy、Bishwajit Ganguly、Pushpito K. Ghosh
DOI:10.1016/j.tet.2009.01.095
日期:2009.4
halohydrins, halo methyl ethers, and halo acetates from olefins using 2:1 Br−/BrO3− and I−/IO3− reagents. In many cases both reagents afforded products selectively in high yields. The highest halogen atom efficiencies attained were 97% and 93% for Br−/BrO3− and I−/IO3−, respectively. Of the two reagents, I−/IO3− was established to be the preferred reagent for vicinal functionalization of linear alkenes and
Tribromoisocyanuric Acid: A New Reagent for Regioselective Cobromination of Alkenes
作者:Pierre Esteves、Marcio de Mattos、Leonardo de Almeida
DOI:10.1055/s-2006-941601
日期:2006.6
A simple one-step method for the preparation of tribromoisocyanuric acid in good yield (87%) has been developed. The reaction of tribromoisocyanuric acid with alkenes in presence of nucleophilic solvents (MeOH, i-PrOH, AcOH and a mixture of H2O-acetone, 1:5) led to the corresponding β-bromoethers, β-bromoacetates and bromohydrins, in high regioselectivity and good yields (73-98%).
Surface polarity of cetyltrimethylammonium bromide (CTAB) aqueous micelles was checked by use of as a probe the bromination reaction of a series of 1-alkenes and a water-soluble alkene, cis-4-cyclohexene-1,2-dicarboxylic acid dimethyl ester (I). There was strong inhibition (10(5)-10(6)-fold) of the second-order reaction rate constants relative to those in water; moreover, both kinetics and the product distributions suggested that alkenes had different locations at the micellar surface. Kinetics in the presence of added NaBr and n-decane supported this location hypothesis.