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Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
C2-symmetric cyclic selenium-catalyzed enantioselective bromoaminocyclization
Feng Chen1, Chong Kiat Tan, Ying-Yeung Yeung
1Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543.
Journal of the American Chemical Society
|January 15, 2013
Summary
This study introduces a novel catalytic asymmetric bromocyclization for creating chiral pyrrolidines from olefinic amides. These pyrrolidines can be transformed into highly enantioenriched piperidines, showcasing a new synthetic pathway.
Area of Science:
- Organic Chemistry
- Asymmetric Catalysis
- Synthetic Methodology
Background:
- Developing efficient methods for synthesizing complex nitrogen-containing heterocycles is crucial in medicinal chemistry.
- Asymmetric catalysis offers a powerful approach to control stereochemistry in organic synthesis.
Purpose of the Study:
- To report a novel catalytic asymmetric bromocyclization of trisubstituted olefinic amides.
- To develop a stereoselective synthesis of enantioenriched pyrrolidine and piperidine derivatives.
Main Methods:
- Utilized a C(2)-symmetric mannitol-derived cyclic selenium catalyst.
- Employed N-bromophthalimide as the brominating agent.
- Investigated the rearrangement of pyrrolidine products to piperidines.
Main Results:
- Achieved catalytic asymmetric bromocyclization of trisubstituted olefinic amides.
- Generated enantioenriched pyrrolidine products with two stereogenic centers.
- Demonstrated rearrangement to 2,3-disubstituted piperidines with high diastereoselectivity and enantiospecificity.
Conclusions:
- The developed method provides efficient access to valuable chiral pyrrolidines and piperidines.
- The catalytic system offers a new strategy for stereocontrolled synthesis of nitrogen heterocycles.
- The high enantiospecificity of the rearrangement is a key feature of this transformation.
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