- Monobromoborane-dimethyl sulfide - A highly promising reagent for the regio- and chemoselective brominative cleavage of terminal epoxides into vicinal bromohydrins
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Monobromoborane?dimethyl sulfide (BH2Br?SMe2) is a highly regio- and chemoselective reagent useful for the brominative cleavage of the epoxy moiety into bromohydrins in the presence of alkenes, alkynes, ethers, acetals, ketals, and acetonides at 0°C, besides being an excellent hydroborating reagent. Several reactive functional groups, such as chloride, ketones, esters, nitriles, nitros, and thioethers, have been accommodated during such transformations. Although the reduction of acetophenone was completely suppressed at ?25°C, 4-chlorobenzaldehyde still underwent 12?13% reduction of an aldehydic group. CSIRO 2007.
- Roy, Chandra D.,Brown, Herbert C.
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p. 139 - 145
(2008/02/11)
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- Dimethoxyboron bromide - A new, efficient, regio- and chemoselective reagent for the conversion of terminal epoxides into bromohydrins
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Dimethoxyboron bromide, (MeO)2BBr, easily prepared in excellent yield from boron tribromide and trimethyl borate, is a new, efficient, regio- and chemoselective reagent useful for the halogenative cleavage of compounds containing epoxy groups into vicinal bromohydrins in the presence of ether, acetal, ketal, N-oxide, and sulfoxide groups, at low temperatures (-78°C).
- Roy, Chandra D.,Brown, Herbert C.
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p. 639 - 641
(2007/10/03)
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- HALONIUM ION-INDUCED BIOSYNTHESIS OF CHLORINATED MARINE METABOLITES
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Bromoperoxidases do not directly oxidize the chloride ion; nevertheless, in the presence of bromide ions, chloride ions and hydrogen peroxide, bromoperoxidases react with alkenes and alkynes to produce bromochloro-derivatives.This same reaction is catalysed when seawater is the source of chloride and bromide ions.This suggests that bromonium ion-induced biosynthesis of chlorinated metabolites occurs in marine environments.The role of iodonium ions in the biosynthesis of chlorinated metabolites is also discussed.Key Word Index - Coralina sp.; Rhodophyta; biological halogenation; bromoperoxidase; enzymatic bromochlorination; marine chlorination; role of bromonium ions and iodonium ions; seawater.
- Geigert, John,Neidleman, Saul L.,Witt, Susanne K. de,Dalietos, Demetrios J.
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p. 287 - 290
(2007/10/02)
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