Self-Supported Chiral Dirhodium Organic Frameworks Enables Efficient Asymmetric Cyclopropanation

Area of Science:

• Organic Chemistry
• Catalysis
• Materials Science

Background:

• Developing heterogeneous chiral dirhodium catalysts is crucial for synthesizing bioactive compounds and reducing noble metal loss.
• Existing methods face challenges in multi-step synthesis and rhodium leaching from solid supports.

Purpose of the Study:

• To create efficient, recyclable, self-supported chiral dirhodium organic frameworks for heterogeneous asymmetric catalysis.
• To overcome synthetic challenges and rhodium leaching issues in dirhodium catalysis.

Main Methods:

• Employed a Suzuki-Miyaura coupling reaction for a self-supported strategy.
• Constructed two chiral dirhodium organic frameworks (Rh2-MOCP-1 and Rh2-MOCP-2).
• Utilized these frameworks as heterogeneous catalysts in asymmetric cyclopropanation reactions.

Main Results:

• The synthetic approach was simple, efficient, and did not require additional catalyst supports.
• The chiral dirhodium materials demonstrated high efficiency and recyclability as heterogeneous catalysts.
• Rh2-MOCP-2 achieved a 93.9% yield and 80.9% enantiomeric excess (ee), surpassing previous heterogeneous catalysts.

Conclusions:

• The novel self-supported chiral dirhodium frameworks offer a simplified and effective route for heterogeneous asymmetric catalysis.
• These materials exhibit excellent catalytic performance and recyclability, comparable to homogeneous counterparts.
• The strategy effectively addresses rhodium leaching and simplifies catalyst preparation.