Chapter 14: Organometallic Compounds

Compounds that contain a metal-carbon bond, R-M, are known as "organometallic" compounds.
Organometallic compounds of Li, Mg (Grignard reagents) are amongst some of the most important organic reagents.
Many other metals have been utilised, for example Na, Cu and Zn.

Organometallic compounds provide a source of nucleophilic carbon atoms which can react with electrophilic carbon to form a new carbon-carbon bond.  This is very important for the synthesis of complex molecules from simple starting materials.

To rationalise the general reactivity of organometallics it is convenient to view them as ionic, so R-M  =  R^-M⁺

The most important reactions is this chapter are the reactions of organolithiums, RLi, and Grignard reagents, RMgX, with the carbonyl groups in aldehydes, ketones and esters to give alcohols. However, we will also look at some useful reactions involving Cu, Zn and Hg (mercury).

Organometallic Compounds

• Nomenclature
• Structure
• Reactivity
• Basicity

• Organolithiums RLi
• Organomagnesium or Grignards, RMgX
• Dialkyllithium cuprates, R₂CuLi
• Organozinc reagents, RZnX
• Acetylides, RC≡CM

• Overview of Reactions
• Overview of Grignard Reactions
• Addition of RLi and RMgX to Aldehydes and Ketones
• Addition of RC≡CM to Aldehydes and Ketones
• Addition of RLi and RMgX to Esters
• Alkane synthesis using R₂CuLi
• Reactions of RZnX: Simmons-Smith cyclopropanation
• Oxymercuration-Demercuration of Alkenes

• How to Plan a Synthesis

• Sample Questions

© Dr. Ian Hunt, Department of Chemistry