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Lithium-halogen exchange vinyl bromide

Lithium-halogen exchange with t-BuLi may also be used to prepare vinyllithiums from vinyl bromides or iodides with complete retention of configuration. Pioneering studies by the Seebach... [Pg.212]

This reaction can be extended to di- and trisubstituted alkenes by use of substituted vinyllithium reagents. These can be prepared quantitatively from vinyl chlorides or bromides by reaction in ether with lithium powder (containing 2% sodium) or from vinyl bromides by halogen—metal exchange with an alkyl-lithium. [Pg.666]

Vinyl chlorides react more sluggishly than bromides and iodides. Equations (w)-(x) show that chloride-lithium exchanges can work well, but with side reactions. The major alternative to Cl-Li exchange is metallation of the acidic a hydrogen (see 5.5.2.3.2), which occurs with vinyl fluorides if no other halogen is present. [Pg.143]

See other pages where Lithium-halogen exchange vinyl bromide is mentioned: [Pg.206]    [Pg.206]    [Pg.141]    [Pg.157]    [Pg.157]    [Pg.139]    [Pg.807]    [Pg.625]    [Pg.113]    [Pg.470]    [Pg.470]    [Pg.247]    [Pg.13]    [Pg.470]    [Pg.613]    [Pg.130]    [Pg.204]    [Pg.19]    [Pg.23]    [Pg.82]    [Pg.35]    [Pg.252]    [Pg.107]    [Pg.1147]    [Pg.57]   
See also in sourсe #XX -- [ Pg.212 ]



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Halogenation vinylic

Lithium bromide

Lithium vinyl

Lithium-halogen exchange

Vinyl bromide

Vinylic bromides

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