Halides carbon-halogen bond reaction number

The second technique of CRP is ATRP first described by Wang and Matyjaszewski [38] and by Sawamoto and co-workers [39]. This technique, since reviewed in a number of monographies and feature articles [22,40-42] involves the reversible homolytic cleavage of a carbon-halogen bond by a redox reaction between the organic halide and a copper halide (in the presence of a ligand, e.g. bipyridine) which yields the initiating radical and the oxidized copper complex ... 

Electrophilic addition of a hydrogen halide to an alkene is the addition of a halogen (Cl, Br, or I) and H across the carbon-carbon double bond. The reaction occurs with Markovnikov regioselectivity with the H adding to the carbon with the greater number of hydrogens. 

As a general rule, and as shown in the fifth example in Table 6.7, bromine (Br2) and chlorine (CI2) in, for example, carbon tetrachloride (tetrachloromethane, CCI4) solution, add across the carbon-carbon triple bond to give tram- [antarafacial, and-, or ( )] dibromoalkene. Also, as a general rule (albeit with a very limited number of comparisons), these addition reactions occur more slowly with alkynes than they do with alkenes and a second equivalent of halogen can add to produce the tetra-halide (Equation 6.68). 

MarkownikofT s rule The rule states that in the addition of hydrogen halides to an ethyl-enic double bond, the halogen attaches itself to the carbon atom united to the smaller number of hydrogen atoms. The rule may generally be relied on to predict the major product of such an addition and may be easily understood by considering the relative stabilities of the alternative carbenium ions produced by protonation of the alkene in some cases some of the alternative compound is formed. The rule usually breaks down for hydrogen bromide addition reactions if traces of peroxides are present (anti-MarkownikofT addition). 

The resulting tin-centered radicals can react with a variety of organohaUdes (or related compounds) to efficiently form carbon-centered radicals this type of reaction has played a central role in the development of synthetic and mechanistic organic radical chemistry. > Halogen-atom abstraction from alkyl or aryl halides allows the controlled formation of a variety of carbon-centered radicals, which can undergo a number of intra- or intermolecular carbon-carbon bond forming reactions. This includes cascade (or... 

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