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Hydrogen halide, addition to alkenes

Carbocation Rearrangements in Hydrogen Halide Addition to Alkenes... [Pg.241]

CARBOCATION REARRANGEMENTS IN HYDROGEN HALIDE ADDITION TO ALKENES... [Pg.241]

Sections See Table 6 6 Hydrogen halide addition to alkenes proceeds by elec... [Pg.271]

The order of reactivity of the hydrogen halides is HI > HBr > HCl, and reactions of simple alkenes with HCl are quite slow. The studies that have been applied to determining mechanistic details of hydrogen halide addition to alkenes have focused on the kinetics and stereochemistry of the reaction and on the effect of added nucleophiles. The kinetic studies often reveal complex rate expressions which demonstrate that more than one process contributes to the overall reaction rate. For addition of hydrogen bromide or Itydrogen... [Pg.353]

We can gain a general understanding of the mechanism of hydrogen halide addition to alkenes by extending some of the principles of reaction mechanisms introduced earlier. In Section 5.12 we pointed out that carbocations are the conjugate acids of alkenes. Therefore, strong acids such as HCI, HBr, and HI can protonate the double bond of an alkene to fonn a car bocation. [Pg.236]

See Table 6.6. Hydrogen halide addition to alkenes proceeds by electrophilic attack of the reagent on the tt electrons of the double bond. Car-bocations are intermediates. [Pg.278]

We use the term substitution with scheme (138) in the sense that it is used for aromatic compounds. Addition is reserved for processes in which a saturated intermediate is formed. To observe retention, we require only that k 2) > k(3) in (138). By analogy with the SB2 reactions at a saturated carbon (Rreevoy et al., 1967), it is probable that some demetalations with acid in a polar solvent proceed in this way. Certainly, the intermediates are wholly analogous to those proposed for the isomerization, hydration, or hydrogen halide addition to alkenes. [Pg.268]

The mechanism is similar to the mechanism of hydrogen halide addition to alkenes. The vinyl cation formed in the first step is more stable with the positive charge on the more highly substituted carbon atom. Attack by halide ion completes the reaction. [Pg.409]

Hydrogen halide addition to alkenes and alkynes yields organohalides ... [Pg.236]

There is a competing reaction with solvent when hydrogen halide additions to alkenes are carried out in nucleophilic solvents. [Pg.479]

The characteristic chemical property of a C=C structural unit is susceptibility to attack by electrophiles. Electrons flow from the tt component of the double bond toward the electrophile and ultimately become a shared-electron pair in a covalent bond. WeTl see numerous other examples of electrophilic addition to alkenes in this chapter. First, however, we need to extend our discussion of hydrogen halide addition to alkenes of various types. [Pg.233]


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Addition of Hydrogen Halides to Alkenes

Addition of a Hydrogen Halide to an Alkene

Addition of hydrogen halides or halogens to alkenes

Addition, hydrogenation

Additives, hydrogenated

Alkenes hydrogen halides

Alkenes hydrogenation

Carbocation Rearrangements in Hydrogen Halide Addition to Alkenes

Electrophilic Addition of a Hydrogen Halide to an Alkene

Electrophilic addition of hydrogen halides to alkenes

Halide additives

Hydrogen halides

Hydrogen halides addition

Hydrogen halides to alkenes

Hydrogenation hydrogen halides, additions

Hydrogenation, halides

Hydrogenative addition

Rearrangements in hydrogen halide addition to alkenes

Stereoselectivity addition of hydrogen halides to alkenes

To halide

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