Gilman Reagent

Definition

The Gilman reagent, also known as the cuprate reagent, is an organometallic compound used in organic chemistry for the formation of carbon-carbon bonds through coupling reactions. It is a powerful tool in the synthesis of complex organic molecules.

5 Must Know Facts For Your Next Test

1. Gilman reagents are typically formed by the reaction of an organolithium or Grignard reagent with a copper(I) salt, such as CuI or CuCN.
2. They are highly reactive and can undergo a wide range of coupling reactions, including conjugate additions, allylic substitutions, and cross-couplings.
3. Gilman reagents exhibit enhanced reactivity and selectivity compared to their corresponding organolithium or Grignard reagents, making them useful in complex organic synthesis.
4. The copper atom in the Gilman reagent acts as a Lewis acid, activating the carbon-metal bond and facilitating the coupling reaction.
5. Gilman reagents are typically generated and used in situ, as they are often unstable and sensitive to air and moisture.

Review Questions

• Explain the formation and structure of a Gilman reagent.
  • A Gilman reagent is formed by the reaction of an organolithium or Grignard reagent with a copper(I) salt, such as CuI or CuCN. This reaction combines the nucleophilic properties of the organometallic species with the Lewis acidic nature of the copper atom, creating a highly reactive cuprate complex. The resulting Gilman reagent typically has the general formula R$_2$CuLi or R$_2$CuMgX, where R represents an organic group and X is a halide or other counterion.
• Describe the enhanced reactivity and selectivity of Gilman reagents compared to other organometallic reagents.
  • Gilman reagents exhibit enhanced reactivity and selectivity compared to their corresponding organolithium or Grignard reagents. The presence of the copper atom in the Gilman reagent acts as a Lewis acid, activating the carbon-metal bond and facilitating the coupling reaction. This increased reactivity allows Gilman reagents to undergo a wider range of coupling reactions, including conjugate additions, allylic substitutions, and cross-couplings, with improved selectivity and control over the desired transformation. The copper atom also helps to stabilize and direct the reactivity of the organometallic species, making Gilman reagents a powerful tool in complex organic synthesis.
• Discuss the importance of Gilman reagents in the context of 10.7 Organometallic Coupling Reactions and their role in the synthesis of complex organic molecules.
  • Gilman reagents are a crucial class of organometallic compounds in the context of 10.7 Organometallic Coupling Reactions. Their ability to form new carbon-carbon bonds through a variety of coupling reactions, such as conjugate additions, allylic substitutions, and cross-couplings, makes them invaluable tools in the synthesis of complex organic molecules. The enhanced reactivity and selectivity of Gilman reagents, compared to other organometallic species, allows for the construction of intricate molecular frameworks with a high degree of control and efficiency. This makes Gilman reagents indispensable in the field of organic synthesis, where the ability to selectively form carbon-carbon bonds is crucial for the development of complex natural products, pharmaceuticals, and other important organic compounds.

Related terms

Organometallic Compound: A compound that contains a direct carbon-metal bond, combining the properties of organic and inorganic compounds.

Coupling Reaction: A reaction that forms a new carbon-carbon bond between two reactants, often used to construct complex organic structures.

Nucleophilic Substitution: A reaction in which a nucleophile (electron-rich species) attacks an electrophilic carbon center, replacing a leaving group.