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The reaction thus provides a more stereospecific and complementary regiochemical alternative to other hydration reactions such as acid-catalyzed addition and the oxymercuration–reduction process. The reaction was first reported by Herbert C. Brown in the late 1950s [2] and it was recognized in his receiving the Nobel Prize in Chemistry in 1979.
Bromine water, Br 2. Bromine water is an oxidizing, intense brown mixture containing diatomic bromine (Br 2) dissolved in water (H 2 O). [1] It is often used as a reactive in chemical assays of recognition for substances which react with bromine in an aqueous environment with the halogenation mechanism, mainly unsaturated carbon compounds (carbon compounds with 1 or more double or triple bond(s)).
NBS reacts with alkenes in aqueous solvents to give bromohydrins. The preferred conditions are the portionwise addition of NBS to a solution of the alkene in 50% aqueous DMSO, DME, THF, or tert-butanol at 0 °C. [3] Formation of a bromonium ion and immediate attack by water gives strong Markovnikov addition and anti stereochemical selectivities ...
Hydroboration of 1,2-disubstituted alkenes, such as a cis or trans olefin, produces generally a mixture of the two organoboranes of comparable amounts, even if the steric properties of the substituents are very different. For such 1,2-disubstituted olefins, regioselectivity can be observed only when one of the two substituents is a phenyl ring.
These occur between alkenes and electrophiles, often halogens as in halogen addition reactions. Common reactions include use of bromine water to titrate against a sample to deduce the number of double bonds present. For example, ethene + bromine → 1,2-dibromoethane: C 2 H 4 + Br 2 → BrCH 2 CH 2 Br. This takes the form of 3 main steps shown ...
In chemistry, the haloform reaction (also referred to as the Lieben haloform reaction) is a chemical reaction in which a haloform (CHX 3, where X is a halogen) is produced by the exhaustive halogenation of an acetyl group (R−C(=O)CH 3, where R can be either a hydrogen atom, an alkyl or an aryl group), in the presence of a base. [1] [2] [3 ...
EuBr 3 + 1 / 2 H 2 → EuBr 2 + HBr 2 TaBr 4 500 °C → TaBr 3 + TaBr 5 Most of the bromides of the pre-transition metals (groups 1, 2, and 3, along with the lanthanides and actinides in the +2 and +3 oxidation states) are mostly ionic, while nonmetals tend to form covalent molecular bromides, as do metals in high oxidation states from ...
2 HBr + H 2 SO 4 → Br 2 + SO 2 + 2 H 2 O. The acid may be prepared by: reaction of bromine with water and sulfur: [14] 2 Br 2 + S + 2 H 2 O → 4 HBr + SO 2; bromination of tetralin: [14] C 10 H 12 + 4 Br 2 → C 10 H 8 Br 4 + 4 HBr; reduction of bromine with phosphorous acid: [9] Br 2 + H 3 PO 3 + H 2 O → H 3 PO 4 + 2 HBr