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Chiral Brønsted Acid-Catalyzed Metal-Free Asymmetric Direct Reductive Amination Using 1-Hydrosilatrane.
Vladislav Skrypai1, Sami E Varjosaari1,2, Fawwaz Azam3
1Department of Chemistry & Biochemistry , Northern Illinois University , 1425 W. Lincoln Hwy. , DeKalb , Illinois 60115 , United States.
The Journal of Organic Chemistry
|April 12, 2019
Summary
Researchers developed a new method for asymmetric reductive amination using a silane as the hydride source. This practical approach efficiently produces chiral secondary amines at room temperature with high enantiomeric excess.
Area of Science:
- Organic Chemistry
- Asymmetric Catalysis
- Green Chemistry
Background:
- Direct reductive amination is crucial for synthesizing chiral amines.
- Existing methods often require harsh conditions or specialized reagents.
- Developing catalytic systems using practical hydride sources remains a challenge.
Purpose of the Study:
- To report the first chiral Brønsted acid-catalyzed asymmetric reductive amination using a silane.
- To establish a practical and efficient method for synthesizing chiral secondary amines from prochiral ketones and aryl amines.
Main Methods:
- Utilized 1-hydrosilatrane as a practical hydride source.
- Employed a chiral Brønsted acid catalyst for asymmetric induction.
- Conducted the reaction under mild, ambient conditions (room temperature, air/moisture tolerant).
Main Results:
- Achieved high conversion rates for the asymmetric reductive amination.
- Obtained desired chiral secondary amines with enantiomeric excess up to 84%.
- Demonstrated minimal side product formation, indicating high selectivity.
Conclusions:
- The reported method offers a novel and practical route to chiral secondary amines.
- This work highlights the potential of silanes as hydride sources in asymmetric catalysis.
- The reaction's efficiency and mild conditions make it suitable for broader synthetic applications.
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