Formula: C6H4BBrF3KOn September 7, 2011 ,《Expanded Substrate Scope and Improved Reactivity of Ether-Forming Cross-Coupling Reactions of Organotrifluoroborates and Acetals》 was published in Journal of the American Chemical Society. The article was written by Vo, Cam-Van T.; Mitchell, T. Andrew; Bode, Jeffrey W.. The article contains the following contents:
Mixed acetals and organotrifluoroborates undergo BF3·OEt2-promoted cross-couplings to give dialkyl ethers under simple, mild conditions. A survey of reaction partners identified a hydroxamate leaving group that improves the regioselectivity and product yield in the BF3·OEt2-promoted coupling reaction of mixed acetals and potassium alkynyl-, alkenyl-, aryl- and heteroaryltrifluoroborates to access substituted dialkyl ethers. This leaving group enables the reaction to proceed rapidly under mild conditions (0 °C, 5-60 min) and permits reactions with electron-deficient potassium aryltrifluoroborates that are less reactive with other acetal substrates. A study of the reaction mechanism and characterization of key intermediates by NMR spectroscopy and X-ray crystallog. identified a role for the hydroxamate moiety as a reversible leaving group that serves to stabilize the key oxocarbenium intermediate and the need for a slight excess of organodifluoroborane to serve as a catalyst. A secondary role for the boron nucleophile as an activating ligand was also considered. These studies provide the basis for a general class of reagents that lead to dialkyl ethers by a simple, predictable cross-coupling reaction. In the experiment, the researchers used potassium (3-bromophenyl)trifluoroborate(cas: 374564-34-8Formula: C6H4BBrF3K)
potassium (3-bromophenyl)trifluoroborate(cas: 374564-34-8) belongs to organobromine compounds.The reactivity of organobromine compounds resembles but is intermediate between the reactivity of organochlorine and organoiodine compounds. Formula: C6H4BBrF3K Dehydrobromination, Grignard reactions, reductive coupling, Wittig reaction, and several nucleophilic substitution reactions are some of the principal reactions which involve organic bromides.
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary