Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Hydrogen bromide free-radical addition, alkenes

FREE-RADICAL ADDITION OF HYDROGEN BROMIDE TO ALKENES... [Pg.242]

Free Radical Addition of Hydrogen Bromide to Alkenes... [Pg.243]

The regioselectivity of addition of HBr to alkenes under normal (electrophilic addi tion) conditions is controlled by the tendency of a proton to add to the double bond so as to produce the more stable carbocatwn Under free radical conditions the regioselec tivity IS governed by addition of a bromine atom to give the more stable alkyl radical Free radical addition of hydrogen bromide to the double bond can also be initiated photochemically either with or without added peroxides... [Pg.244]

Among the hydrogen halides only hydrogen bromide reacts with alkenes by both electrophilic and free radical addition mechanisms Hydrogen iodide and hydrogen chlo ride always add to alkenes by electrophilic addition and follow Markovmkov s rule Hydrogen bromide normally reacts by electrophilic addition but if peroxides are pres ent or if the reaction is initiated photochemically the free radical mechanism is followed... [Pg.245]

Hydrogen bromide is unique among the hydrogen halides m that it can add to alkenes either by electrophilic or free radical addition Under photochemical conditions or m the presence of peroxides free radical addition is observed and HBr adds to the double bond with a regio selectivity opposite to that of Markovmkov s rule... [Pg.274]

Hydrogen bromide (but not hydrogen chloride or hydrogen iodide) adds to alkynes by a free radical mechanism when peroxides are present m the reaction mixture As m the free radical addition of hydrogen bromide to alkenes (Section 6 8) a regioselectiv ity opposite to Markovmkov s rule is observed... [Pg.379]


See other pages where Hydrogen bromide free-radical addition, alkenes is mentioned: [Pg.243]    [Pg.245]    [Pg.243]    [Pg.245]    [Pg.250]    [Pg.252]    [Pg.221]    [Pg.223]    [Pg.221]    [Pg.223]    [Pg.1229]    [Pg.1232]    [Pg.739]    [Pg.255]   
See also in sourсe #XX -- [ Pg.242 , Pg.243 , Pg.251 ]




SEARCH



Addition, hydrogenation

Additives, hydrogenated

Alkenes free radical addition

Alkenes hydrogen bromide addition

Alkenes hydrogenation

Alkenes radical addition

Alkenes radicals

Bromides alkenes

Bromides hydrogenation

Free radical addition

Hydrogen bromid

Hydrogen bromide

Hydrogen bromide alkenes

Hydrogen bromide free radical addition

Hydrogen, free

Hydrogenative addition

Radical addition hydrogen bromide

© 2024 chempedia.info