Gilman Reagents

Definition

Gilman reagents, also known as organocopper reagents, are a class of organometallic compounds containing copper that are used as powerful nucleophiles in organic synthesis, particularly in conjugate addition reactions to α,β-unsaturated carbonyl compounds.

5 Must Know Facts For Your Next Test

1. Gilman reagents are typically prepared by the reaction of an organolithium or Grignard reagent with a copper(I) halide, forming a copper-carbon bond.
2. They are highly reactive and selective nucleophiles, allowing for the addition of the copper-containing group to the β-carbon of α,β-unsaturated aldehydes and ketones.
3. Gilman reagents can undergo 1,4-addition (conjugate addition) to α,β-unsaturated carbonyl compounds, resulting in the formation of a new carbon-carbon bond.
4. The presence of copper in Gilman reagents enhances their reactivity and selectivity compared to other organometallic reagents, making them useful in complex organic synthesis.
5. Gilman reagents are often used in the synthesis of natural products, pharmaceuticals, and other important organic molecules due to their ability to selectively functionalize α,β-unsaturated carbonyl systems.

Review Questions

• Describe the structure and preparation of Gilman reagents.
  • Gilman reagents are organometallic compounds containing a copper-carbon bond. They are typically prepared by the reaction of an organolithium or Grignard reagent with a copper(I) halide, such as copper(I) iodide or copper(I) bromide. This process forms a copper-containing nucleophilic species that can then be used in organic synthesis, particularly in conjugate addition reactions to α,β-unsaturated carbonyl compounds.
• Explain the reactivity and selectivity of Gilman reagents in conjugate addition reactions.
  • Gilman reagents are highly reactive and selective nucleophiles, making them useful in organic synthesis. The presence of copper in the Gilman reagent enhances its reactivity and selectivity compared to other organometallic reagents. Gilman reagents can undergo 1,4-addition (conjugate addition) to the β-carbon of α,β-unsaturated aldehydes and ketones, resulting in the formation of a new carbon-carbon bond. This selective functionalization of the α,β-unsaturated carbonyl system is a key feature of Gilman reagents and makes them valuable tools in the synthesis of complex organic molecules.
• Discuss the importance of Gilman reagents in organic synthesis, particularly in the context of 19.13 Conjugate Nucleophilic Addition to α,β‑Unsaturated Aldehydes and Ketones.
  • Gilman reagents are essential in organic synthesis, especially in the context of 19.13 Conjugate Nucleophilic Addition to α,β‑Unsaturated Aldehydes and Ketones. Their ability to selectively functionalize the β-carbon of α,β-unsaturated carbonyl compounds through conjugate addition reactions makes them valuable tools for the synthesis of natural products, pharmaceuticals, and other important organic molecules. The copper-containing nature of Gilman reagents enhances their reactivity and selectivity, allowing for the introduction of new carbon-carbon bonds in a controlled manner. This is a crucial step in the construction of complex organic structures, which is a key focus of the topics covered in section 19.13.

Related terms

Conjugate Addition:

A type of nucleophilic addition reaction where the nucleophile adds to the β-carbon of an α,β-unsaturated carbonyl compound, forming a new carbon-carbon bond.

Organometallic Compounds:

Compounds that contain a direct carbon-metal bond, often used as highly reactive nucleophiles or reducing agents in organic synthesis.

Nucleophile:

A species that donates an electron pair to form a new bond, typically attacking electrophilic carbon centers.