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Organic Chemistry by Brown, Iverson, Anslyn, Foote | Mayya's Study Guide | Chapter 15

Chapter 15: An Introduction to Organometallic Compounds


Table of Contents:

  • Organomagnesium and Organolithium Compounds

  • Reactions Of Grignard And Organolithium

  • Lithium Diorganocopper (Gilman) Reagents

  • Carbenes and Carbenoids



Organomagnesium and Organolithium Compounds


Organomagnesium (Grignard reagent) has a formula of RMgX where X is Br, Cl or I.

Organolithium has a formula of R-Li.


Making Grignard And Organolithium


To make Grignard reagent, we must start with an alkyl halide where the halogen is Br, Cl or I. We then react it with Mg/ether.

Product: Replace X with MgX


To make organolithium reagent, we must start with an alkyl halide where the halogen is Br, Cl or I. We then react it with 2Li.

Product: Replace X with Li

how to make organolithium reagent
how to make organolithium reagent

Reactions Of Grignard And Organolithium

Both Grignard and organolithium compounds are very strong acids and will get protonated in the presence of H2O, ROH or any acid.


Reaction of Grignard reagent with water
Reaction of Grignard reagent with water

In the first example, Grignard reagent is reacting with water. MgBr is replaces by H.

In the second example, Organolithium reagent is reaction with alcohol. In this case, instead of H alcohol has D, deuterium which is an isotope of hydrogen. Li gets replaced by D in the product.


Reactions of Grignard and Organolithium with Epoxide


An epoxide will react with either Grignard reagent or Organolithium reagent.

Product: Get rid of the epoxide, and attach OH to the most substituted carbon

from the epoxide and R on the least substituted carbon from the epoxide. (attach carbon that was attached to MgX and what is it connected to).


Mechanism for the reaction of epoxide with Grignard reagent.

Mechanism for the reaction of epoxide with Grignard reagent
Mechanism for the reaction of epoxide with Grignard reagent

How to predict the reactants from the epoxide + RMgBr (RLi) product

Mayya's Trick

  1. Break the bond between C with OH and the least substituted carbon it is attached to

  2. Attach MgBr or Li to the carbon broken

  3. Remove H from OH and attach O to the neighboring carbon making an epoxide


How to predict the reactants from the epoxide + RMgBr (RLi) product
How to predict the reactants from the epoxide + RMgBr (RLi) product

Lithium Diorganocopper (Gilman) Reagents


Making Gilman Reagent

We need to start with 2R-Li and react it with CuI with either diethyl ether or THF.

Product: (R)2CuLi

Making Gilman Reagent
Making Gilman Reagent

Vynilic Halide Reaction with Gilman Reagent


Vinilyic halide is a molecule that has a halogen attached to the double bond.


Product: Get rid of the halogen and attach the carbon that was connected to halogen to the carbon from 1 R group from (R)2CuLi. The configuration of the carbon carbon double bond is preserved

Vynilic Halide Reaction with Gilman Reagent
Vynilic Halide Reaction with Gilman Reagent

Epoxide with Gilman Reagent Reaction

Product: Get rid of the epoxide, and attach OH to the most substituted carbon from the epoxide and R (only 1) on the least substituted carbon from the epoxide.

Epoxide with Gilman Reagent Reaction
Epoxide with Gilman Reagent Reaction

Carbenes and Carbenoids

Carbenes are highly reactive and behave as electrophiles.







Making Carbenes and Carbene Reaction

Making Carbenes and Carbene Reaction
Making Carbenes and Carbene Reaction

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