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Direct lithiation hydrocarbons

This procedure illustrates a general method for the preparation of alkenes from the pal 1 adium(Q)-cata1yzed reaction of vinyl halides with organo-lithium compounds, which can be prepared by various methods, including direct regioselective lithiation of hydrocarbons. The method is simple and has been used to prepare a variety of alkenes stereoselectively. Similar stoichiometric organocopper reactions sometimes proceed in a nonstereoselective... [Pg.45]

Reaction conditions can be modified to accelerate the rate of lithiations when necessary. Addition of tertiary amines, especially tetramethylethylenediamine (TMEDA), accelerates lithiation, probably by chelating the lithium metal and promoting the formation of monomeric reagent. Hydrocarbons lacking directing substituents are not usually very reactive toward metalation but it has been found that a mixture of n-butyllithium and potassium r-butoxide is sufficiently reactive... [Pg.252]

See other pages where Direct lithiation hydrocarbons is mentioned: [Pg.171]    [Pg.258]    [Pg.1]    [Pg.55]    [Pg.60]    [Pg.1833]    [Pg.377]    [Pg.17]    [Pg.140]    [Pg.420]    [Pg.1093]    [Pg.193]    [Pg.62]    [Pg.605]    [Pg.284]    [Pg.3]    [Pg.1242]   
See also in sourсe #XX -- [ Pg.258 ]



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Direct lithiation

Directed lithiation

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