Variable-Sized bis(4-spiro-fused-β-lactam)-Based Unsaturated Macrocycles: Synthesis and Characterization
Asaad S Mohamed1, Fatma H Al-Awadhi2, Nouria A Al-Awadi1
1Department of Chemistry, Faculty of Science, Kuwait University, P.O. Box 5969, Safat 13060, Kuwait.
ACS Omega
|October 24, 2022
Summary
Researchers report the synthesis of 14 novel unsaturated macrocycles. These complex molecules feature bis-4-spiro-β-lactam structures and were characterized using advanced spectroscopic and crystallographic methods.
Area of Science:
- Organic Chemistry
- Macromolecular Chemistry
- Synthetic Chemistry
Background:
- Macrocycles are important in various fields, including medicinal chemistry and materials science.
- Spirocyclic compounds offer unique three-dimensional structures.
- Bis-spiro-β-lactams represent a challenging synthetic target.
Purpose of the Study:
- To report the synthesis of a new family of 14 unsaturated macrocycles.
- To characterize these novel compounds using comprehensive analytical techniques.
- To explore the syn/anti stereoisomers of bis-4-spiro-β-lactam-based macrocycles.
Main Methods:
- Multistep synthesis involving diimine formation.
- Staudinger [2 + 2] ketene-imine cycloaddition for β-lactam ring formation.
- Ring-closing metathesis (RCM) for macrocycle construction.
Main Results:
- Successful synthesis of 14 new syn/anti bis-4-spiro-β-lactam-based unsaturated macrocycles.
- Structural identification confirmed by Nuclear Magnetic Resonance (NMR) and High-Resolution Mass Spectrometry (HRMS).
- Single-crystal X-ray diffraction analysis provided definitive structural data for key compounds (20b, 23b, 25b-27b).
Conclusions:
- The study presents a viable synthetic route to complex bis-spiro-β-lactam macrocycles.
- The characterized compounds expand the library of accessible macrocyclic structures.
- This work provides a foundation for further investigations into the properties and applications of these novel macrocycles.
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