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Development of Heterogeneous Enantioselective Catalysts using Chiral Metal-Organic Frameworks MOFs

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Selecting reactions and reactants using a switchable rotaxane organocatalyst with two different active sites.

Jack Beswick¹, Victor Blanco¹, Guillaume De Bo¹

¹School of Chemistry , University of Manchester , Oxford Road , Manchester , M13 9PL , UK . Email: david.leigh@manchester.ac.uk ; http://www.catenane.net.

Chemical Science

|May 30, 2017

Summary

This study introduces a switchable rotaxane organocatalyst. Its catalytic activity is controlled by acid or base, enabling selective product formation from multiple reactants.

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Area of Science:

Supramolecular Chemistry
Organic Catalysis

Background:

Rotaxanes are mechanically interlocked molecules with potential applications in catalysis.
Organocatalysts offer environmentally friendly alternatives to metal catalysts.
Controlling catalyst activity and selectivity is crucial for efficient chemical synthesis.

Purpose of the Study:

To develop a switchable rotaxane-based organocatalyst.
To investigate the effect of macrocycle position on catalytic activity.
To demonstrate selective product formation using the switchable catalyst.

Main Methods:

Synthesis of a rotaxane incorporating secondary amine and squaramide catalytic units.
Acid-base treatment to control macrocycle position and catalyst activation.
Reaction of a three-component mixture with the switchable catalyst.

Main Results:

The rotaxane catalyst's activation mode was successfully switched using acid or base.
The macrocycle's position dictated which catalytic site was accessible.
Different products were selectively generated based on the macrocycle's location.

Conclusions:

Switchable rotaxane organocatalysts offer a novel mechanism for controlling chemical reactions.
The precise control over catalytic sites enables selective synthesis.
This approach provides a new platform for designing advanced molecular machines and catalysts.