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Published on: April 4, 2014
Reactions involving di-trans-[12]annulenes
Matthew K Kiesewetter1, Matthew N Gard, Richard C Reiter
1Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, USA.
Researchers synthesized novel annulene derivatives through dehydrohalogenation and ring closure reactions. These findings advance the understanding of complex polycyclic aromatic hydrocarbon formation and reactivity.
Area of Science:
- Organic Chemistry
- Synthetic Chemistry
- Polycyclic Aromatic Hydrocarbons
Background:
- Annulenes are cyclic hydrocarbons with conjugated double bonds.
- Synthesis of complex polycyclic systems remains a challenge in organic chemistry.
Purpose of the Study:
- To explore novel synthetic routes to complex annulene derivatives.
- To investigate the formation of fused ring systems from [12]annulene precursors.
Main Methods:
- Low-temperature dehydrohalogenation of pentabromocyclododecene using potassium tert-butoxide.
- Reaction of [12]annulene with potassium tert-butoxide and 18-crown-6.
- Oxidation and reduction steps to isolate neutral and radical species.
Main Results:
- Formation of the anion radical of 11,12-dihydro-[8]annuleno-[6]annulene from pentabromocyclododecene.
- Isolation of the neutral molecule of 11,12-dihydro-[8]annuleno-[6]annulene.
- Synthesis of the heptalene anion radical from a [12]annulene precursor.
Conclusions:
- The 1,7-di-trans isomer of [12]annulene is a precursor to the heptalene anion radical.
- The study demonstrates a novel pathway for constructing fused polycyclic aromatic systems.
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