Vol 3 No 1


Vol. 3, No. 1
Strong and Hindered Bases in Organic Synthesis
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Introduction / Phosphazene Bases / Verkade's Superbases / Traditional bases
Preservation of Reagents / Aldrich Schlenk-Type Glassware

Bases are a very important class of reagents for synthetic organic chemistry, as in a large amount of reactions the activation of starting materials or reagents through deprotonation is a first step in the synthesis towards new molecules. As different applications and reaction conditions require the use of a specific base, a broad range of inorganic, organic and organometallic bases has been developed and is routinely used. These bases are differentiated by strength, nucleophilicity, steric hindrance and solubility. Special efforts have been invested in optimizing the basicity and in reducing the nucleophilicity of organic bases. These efforts have resulted in several families of interesting molecules.

Fluka and Aldrich are pleased to offer you a broad range of organic bases, from specialized posphazene- and Verkade`s bases, to the traditional alkyl- or aryllithium. The first two classes of exclusive bases are especially suitable for synthetic problems where fine tuning the basicity and the selective sterical hindrance is the key factor to achieve the best results.

Themes discussed in this ChemFile:

  • Phosphazene bases, subdivided into
    • Monomeric phosphazene bases (P1)
    • Dimeric phosphazene bases (P2)
    • Tetrameric phosphazene bases (P4)
  • Verkade's bases
  • Traditional bases, subdivided into
    • amine based traditional bases
    • lithium based traditional bases
    • potassium based traditional bases

Sigma-Aldrich offers you ALL the bases you need for your synthetic work from a single source!

Fluka and Aldrich are proud to offer you a wide range of bases, starting from the traditional MeLi and n-BuLi, to the most specialized, such as Fluka`s TOP EXCLUSIVE phosphazene bases or the Verkade`s bases exclusively from Aldrich.

Sigma-Aldrich stands for Know-How, Quality and Service!

Not only do we supply a wide range of products in this field, we also offer you Know-How, Quality and Service! A whole team of dedicated chemists is here to help you in your daily work!

Prices of these products can be found as separate price lists added to this ChemFile.

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Cover picture presents a phosphazene base in space, made by Armand Tepper

Acknowledgment: We wish to kindly thank Prof. Dr. R Schwesinger, Institute for Organic Chemistry and Biochemistry, University of Freiburg, Germany, for his contributions to this ChemFile on phosphazene bases