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A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
Stereoselective direct reductive amination of ketones with electron-deficient amines using Re2O7/NaPF6 catalyst
Braja Gopal Das1, Prasanta Ghorai
1Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal-462023, India.
Organic & Biomolecular Chemistry
|May 25, 2013
Summary
Direct reductive amination of ketones with electron-deficient amines was achieved using a Re2O7/NaPF6 catalyst. This method offers excellent chemoselectivity and diastereoselectivity for protected amines and cyclohexanones.
Area of Science:
- Organic Chemistry
- Catalysis
- Synthetic Methodology
Background:
- Direct reductive amination (DRA) is a crucial transformation in organic synthesis.
- Developing efficient methods for DRA, especially with challenging substrates like electron-deficient amines (EDA), remains an active research area.
- Existing methods often require harsh conditions or lack broad substrate scope.
Purpose of the Study:
- To report the first successful direct reductive amination of ketones with electron-deficient amines.
- To introduce a novel catalytic system for this transformation.
- To evaluate the chemoselectivity and diastereoselectivity of the developed method.
Main Methods:
- Utilized a catalytic system comprising Re2O7/NaPF6 for the direct reductive amination reaction.
- Employed various ketones and electron-deficient amines, including Cbz-, Boc-, EtOCO-, Fmoc-, Bz-, and ArSO2- protected amines.
- Investigated the reaction conditions to optimize yield and selectivity.
Main Results:
- Achieved the first example of direct reductive amination of ketones with electron-deficient amines.
- Demonstrated excellent chemoselectivity, preserving other functional groups.
- Obtained excellent diastereoselectivity, particularly for 2-alkyl cyclohexanones.
Conclusions:
- The Re2O7/NaPF6 catalytic system provides an efficient route for the direct reductive amination of ketones with electron-deficient amines.
- This methodology expands the scope of DRA and offers high selectivity, making it valuable for complex molecule synthesis.
- The developed method is a significant advancement in synthetic organic chemistry, enabling new pathways for amine synthesis.
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