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Sunday, December 3, 2017

GILMAN'S REAGENT

GILMAN'S REAGENT

Dialkyl lithium cuprates( Gilman's reagent) are very important organo metallic reagents in organic synthesis. These can be prepared by reacting two equivalents of organo lithium reagents with  one equivalent of copper(I) halides (generally bromides and iodides) at low temperatures in the solvent ether or THF.


Applications:
1. Gilman's reagent used to form new C-C bond in coupling reaction with alkyl halides (Corey-House synthesis to make alkanes)

  • Methyl and primary alkyl iodides are preferred
  • This is suitable method than Wurtz reaction to make alkanes with odd number of carbon atoms
2. Gilman's reagens mainly adds to conjugated ketones and aldehydes through 1,4-conjugate addition. Reaction gives more yield in presence of Trimethyl silyl chloride (TMS Chloride) when can be deprotected at the end through aqueous work-up. 



Whereas the addition of Grignard's reagent to conjugated carbonyls proceeds through 1,2-conjugate addition.





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