World Library  
Flag as Inappropriate
Email this Article

Gilman reagent

Article Id: WHEBN0000455584
Reproduction Date:

Title: Gilman reagent  
Author: World Heritage Encyclopedia
Language: English
Subject: Wender Taxol total synthesis, Organocopper compound, Lithium compounds, Lithium, Henry Gilman
Collection: Lithium Compounds, Organocopper Compounds, Reagents for Organic Chemistry
Publisher: World Heritage Encyclopedia
Publication
Date:
 

Gilman reagent

General structure of a Gilman reagent

A Gilman reagent is a chlorides, bromides, and iodides to replace the halide group with an R group. This is extremely useful in creating larger molecules from smaller ones.[1]

Generalized reaction intermediate

These reagents were discovered by Henry Gilman.[2] Lithium dimethylcopper (CH3)2CuLi can be prepared by adding copper(I) iodide to methyllithium in tetrahydrofuran at −78 °C. In the reaction depicted below,[3] the Gilman reagent is a methylating reagent reacting with an alkyne in a conjugate addition, and the negative charge is trapped in a nucleophilic acyl substitution with the ester group forming a cyclic enone.

Scheme 1. Example Gilman reagent reaction

Gilman reagents have complicated structures in crystalline form and in solution. Lithium dimethylcuprate is a dimer in diethyl ether forming an 8-membered ring with two lithium atoms coordinating between two methyl groups. Similarly, lithium diphenylcuprate forms a dimeric etherate, [{Li(OEt2)}(CuPh2)]2, in the solid state.[4]

Lithium diphenylcuprate etherate dimer from crystal structure - 3D stick model Skeletal formula of lithium diphenylcuprate etherate dimer

If the Li+ ions are rendered inert by complexation with the coordination geometry at copper.[5]

Dimethylcuprate anion from crystal structure Diphenylcuprate anion from crystal structure

See also

External links

  • National Pollutant Inventory - Copper and compounds fact sheet

References

  1. ^ J. F. Normant (1972). "Organocopper(I) Compounds and Organocuprates in Synthesis". Synthesis 1972 (02): 63–80.  
  2. ^  
  3. ^ Modern Organocopper Chemistry, N. Krause Ed. Wiley-VCH, 2002.
  4. ^ N. P. Lorenzen, E. Weiss (1990). "Synthesis and Structure of a Dimeric Lithium Diphenylcuprate:[{Li(OEt)2}(CuPh2)]2".  
  5. ^ H. Hope, M. M. Olmstead, P. P. Power, J. Sandell, X. Xu (1985). "Isolation and x-ray crystal structures of the mononuclear cuprates [CuMe2], [CuPh2], and [Cu(Br)CH(SiMe3)2]".  
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
 
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
 
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.
 


Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.