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Questions and Answers
What is the molecular formula of Lithium diisopropylamide (LDA)?
What is the molecular formula of Lithium diisopropylamide (LDA)?
How is LDA commonly prepared?
How is LDA commonly prepared?
What is the pKa value of diisopropylamine?
What is the pKa value of diisopropylamine?
Why is Lithium diisopropylamide (LDA) widely utilized?
Why is Lithium diisopropylamide (LDA) widely utilized?
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What type of compounds can LDA deprotonate?
What type of compounds can LDA deprotonate?
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What happens when the diisopropylamide anion becomes protonated?
What happens when the diisopropylamide anion becomes protonated?
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What is the primary structure of LDA in THF?
What is the primary structure of LDA in THF?
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In which solvent does LDA form temperature-dependent oligomer equilibriums?
In which solvent does LDA form temperature-dependent oligomer equilibriums?
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At room temperature, what are the most likely structures formed by LDA in toluene?
At room temperature, what are the most likely structures formed by LDA in toluene?
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Why is solid LDA considered pyrophoric?
Why is solid LDA considered pyrophoric?
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What is a common and more cost-effective way to prepare LDA for small-scale use (less than 50 mmol)?
What is a common and more cost-effective way to prepare LDA for small-scale use (less than 50 mmol)?
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What type of reaction control is required for kinetic deprotonation of carbon acids?
What type of reaction control is required for kinetic deprotonation of carbon acids?
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Which group does LDA deprotonate in the case of phenylacetone, indicating the kinetic course of deprotonation?
Which group does LDA deprotonate in the case of phenylacetone, indicating the kinetic course of deprotonation?
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Study Notes
Lithium Diisopropylamide (LDA)
- Molecular formula: L(NiPr2)
- Commonly prepared by reacting butyllithium with diisopropylamine
Properties of Diisopropylamine
- pKa value: 36
Utilization of LDA
- Widely utilized due to its strong basicity and ability to deprotonate a wide range of compounds
Deprotonation by LDA
- Can deprotonate carbon acids, including those with pKa values up to 30-40
- Deprotonation of diisopropylamide anion leads to the formation of diisopropylamine and lithium ions
Structure of LDA
- Primary structure in THF: a mixture of monomer, dimer, and tetramer
- Forms temperature-dependent oligomer equilibria in THF
Solvent Effects
- In toluene, the most likely structures formed by LDA at room temperature are dimers and trimers
Safety Considerations
- Solid LDA is considered pyrophoric due to its high reactivity with air and moisture
Preparation of LDA
- For small-scale use (less than 50 mmol), a common and more cost-effective way to prepare LDA is by reacting lithium metal with diisopropylamine
Reaction Control
- Kinetic deprotonation of carbon acids requires tight reaction control to ensure selective deprotonation
Deprotonation of Phenylacetone
- LDA deprotonates the alpha-methyl group of phenylacetone, indicating the kinetic course of deprotonation
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Description
Learn about the chemical compound Lithium diisopropylamide (LDA), its molecular formula, properties, and uses as a strong base in non-polar organic solvents. Explore its synthesis and applications.
