6423-02-5Relevant academic research and scientific papers
Magnetic-nanoparticle-supported 2,2′-bis[3-(triethoxysilyl)propyl] imidazolium-substituted diethyl ether bis(tribromide): A convenient recyclable reagent for bromination
Wu, Liqiang,Yin, Zhikui
, p. 6156 - 6163 (2014/01/06)
A new magnetic-nanoparticle-supported bromination reagent was synthesized by anchoring a 2,2′-bis[3-(triethoxysilyl)propyl]imidazolium-substituted diethyl ether bis(tribromide) onto the surface of γ-Fe2O 3 nanoparticles and subsequently treating this new ionic liquid with bromine. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient bromination of a wide range of alkenes, alkynes, ketones, and aromatic substrates. More importantly, the reagent could be easily recovered by an external magnet and reused six times without significant loss of activity. A new maghemite nanoparticle bromination reagent has been prepared. The nanoparticle reagent was obtained with good loading levels and has been successfully used for the efficient bromination of a wide range of alkenes, alkynes, ketones, and aromatic substrates. Copyright
High quantum yield molecular bromine photoelimination from mononuclear platinum(IV) complexes
Raphael Karikachery, Alice,Lee, Han Baek,Masjedi, Mehdi,Ross, Andreas,Moody, Morgan A.,Cai, Xiaochen,Chui, Megan,Hoff, Carl D.,Sharp, Paul R.
supporting information, p. 4113 - 4119 (2013/05/09)
Pt(IV) complexes trans-Pt(PEt3)2(R)(Br)3 (R = Br, aryl and polycyclic aromatic fragments) photoeliminate molecular bromine with quantum yields as high as 82%. Photoelimination occurs both in the solid state and in solution. Calorimetry measurements and DFT calculations (PMe3 analogs) indicate endothermic and endergonic photoeliminations with free energies from 2 to 22 kcal/mol of Br2. Solution trapping experiments with high concentrations of 2,3-dimethyl-2-butene suggest a radical-like excited state precursor to bromine elimination.
Synthesis of phenacyl bromides via K2S2O 8-mediated tandem hydroxybromination and oxidation of styrenes in water
Jiang, Qing,Sheng, Wenbing,Guo, Cancheng
, p. 2175 - 2179 (2013/09/24)
Non-transition metal-catalyzed synthesis of phenacyl bromides was achieved through K2S2O8-mediated tandem hydroxybromination and oxidation of styrenes. The advantages of this reaction are its excellent functional group compatibility, mild reaction conditions (60 °C) and use of pure water as reaction medium. Based upon experimental observations, a plausible reaction mechanism is proposed.
Sequential bromination reactions from beads with methyltriphenylphosphonium tribromide groups
Cristiano, Rodrigo,Walls, Andrew D.,Weiss, Richard G.
supporting information; experimental part, p. 904 - 909 (2011/09/14)
A reusable bromination reagent based on polystyrene beads with covalently appended methyltriphenylphosphonium tribromide groups has been developed. The results from bromination reactions of several structurally diverse unsaturated substrates with the beads and with solutions of a non-polymeric model brominating reagent, methyltriphenylphosphonium tribromide, are described. It is shown that the reactions are highly regio- and stereo-selective and can be conducted easily. Copyright
Halogen photoreductive elimination from gold(III) centers
Teets, Thomas S.,Nocera, Daniel G.
supporting information; body text, p. 7411 - 7420 (2009/10/17)
Monomeric complexes of the type Au III (PR 3 )X 3 and bimetallic complexes of the type Au 2 I,III [μCH 2 (R 2 P) 2 ]X 4 and Au 2 III,III [μ-CH 2 (R 2 P) 2 ]X 6 (R = Ph, Cy, X = Cl - , Br - ) undergo facile photoelimination of halogen. M-X bond activation and halogen elimination is achieved upon LMCT excitation of solutions of Au III complexes in the presence of olefin chemical traps. As opposed to the typical one-electron redox transformations of LMCT photochemistry, the LMCT photochemistry of the Au III centers allows for theunprecedented (i) two-electron photoelimination of X 2 from a monomeric center and (ii) four-electron photoelimination of X 2 from a bimetalllic center. The quantum yields for X 2 photoproduction, in general, are between 10percent and 20percent for all species, showing only minimal dependence on the identity of the ligands about gold, or the nuclearity of the complex. Efficient X 2 photoelimination is observed in the absence of a chemical trap, providing a rare example of authentic, trap-free halogen elimination from a transitionmetal center.
Stereoselective bromination reactions using tridecylmethylphosphonium tribromide in a "stacked" reactor
Ma, Kefeng,Li, Shaw,Weiss, Richard G.
supporting information; experimental part, p. 4155 - 4158 (2009/06/06)
(Chemical Equation Presented) A new reagent, tridecylmethylphosphonium tribromide, and new procedures for bromination reactions of unsaturated substrates (including one that allows several substrates to be reacted in sequence) are described. The procedures exploit the diffusion of components and the densities and immiscibilities of layers, including a fluorous "spacer" layer, within a reaction vessel. The stereoselectivities achieved in the reactions are superior in some cases to those found with other brominating reagents.
A Mild and Efficient Sonochemical Bromination of Alkenes Using Tetrabutylammonium Tribromide
Berthelot, Jacques,Benammar, Yamina,Lange, Catherine
, p. 4135 - 4136 (2007/10/02)
The bromination of substituted alkenes using tetrabutylammonium tribromide can be effectued under mild conditions with ultrasonic irradiation.This process gives quantitatively the corresponding vicinal dibromide in high yield. Key words: bromination, tribromide, sonication, alkenes, vicinal dibromoalkanes
