This is used in one of my TPR tests. Not sure if this is a typo.
What kind of compund is (CH3)2CuLi?
- Thread starter Deepa100
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It's not a typo. That reagent is used in alkane synthesis to react with Alkyl halides to form Alkanes. The result is similar to what you would expect from an Sn2 reaction, but the mechanisms of this particular reaction is not well understood and is not an Sn2 mechanism.
yes, cuprates (which is the name of this reagent) can react with alkynes to first form substituted alkenes. a second equivalent can then react with the alkene to form an alkane. cuprates are used, as vihsadas said, in SN2-like reactions with alkyl halides, but also for additions across double and triple bonds, particularly non polarized double bonds. the classic example is addition to an alpha/beta unsaturated carbonyl compound. if you react it with a grignard reagent, it will preferentially reduce the carbonyl to an alcohol. if you react it with a cuprate, it will do a michael addition (the product of a michael addition is just to reduce the alpha/beta C=C double bond to a single bond substituted at the beta position).
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it's also used in 1,4 additions to alpha-beta unsaturated compounds. its considered a "soft-nucleophile" unlike "hard nucleophiles" like grignards and hydrides like sleepy wrote. when it adds to the 4, or beta carbon, it moves a pair of electrons from the double bond to the 3, of alpha carbon, making it nucleophilic. after aqueous work up this nucleophilic carbon will become protonated, or can actually undergo alkylation via an unhindered alkyl halide (SN2).
