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Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Highly twisted arenes by Scholl cyclizations with unexpected regioselectivity
Anirban Pradhan1, Pierre Dechambenoit, Harald Bock
1Centre de Recherche Paul Pascal, CNRS & Université de Bordeaux, 115 Avenue Schweitzer, 33600 Pessac, France.
The Scholl reaction readily forms twisted polycyclic aromatic hydrocarbons, even with bulky groups. This method efficiently synthesizes complex helicene structures from simple precursors.
Area of Science:
- Organic Chemistry
- Polycyclic Aromatic Hydrocarbons
- Helicene Synthesis
Background:
- The Scholl reaction is a key method for forming polycyclic aromatic hydrocarbons.
- Steric hindrance often complicates the synthesis of complex aromatic structures.
Purpose of the Study:
- To investigate the stereochemical outcome of the Scholl reaction with quinquephenyl derivatives.
- To explore the synthesis of sterically hindered polycyclic aromatic hydrocarbons.
Main Methods:
- Utilizing the Scholl reaction on quinquephenyl derivatives.
- Employing steric hindrance to direct polycyclization.
Main Results:
- An unexpected strong preference for forming twisted, helicene polycycles was observed.
- The reaction successfully overcame significant steric hindrance.
- Efficient synthesis of hexa-tert-butylhexabenzotriphenylene was achieved from a biaryl starting material.
Conclusions:
- The Scholl reaction provides a facile route to sterically demanding, twisted polycyclic aromatic hydrocarbons.
- This approach enables the efficient construction of complex helicene architectures.
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