Supported Catalysts Useful in Ring-Closing Metathesis, Cross Metathesis, and Ring-Opening Metathesis Polymerization

Area of Science:

• Catalysis
• Polymer Chemistry
• Materials Science

Background:

• Ruthenium and molybdenum catalysts are vital for synthesizing small and large molecules.
• Despite advancements in catalyst activity and selectivity, separation and recycling remain significant challenges.
• Issues include catalyst/product and residue/product separation, impacting process efficiency and sustainability.

Purpose of the Study:

• To review historical and recent efforts in addressing catalyst separation and recycling problems.
• To highlight strategies for catalyst/product and residue/product separation in metathesis catalysis.
• To focus on advancements in ring-opening metathesis polymerization (ROMP) chemistry.

Main Methods:

• Discussion of separation techniques in small molecule synthesis (ring-closing and cross metathesis).
• Detailed examination of biphasic separation approaches (solid/liquid and liquid/liquid) in ROMP.
• Exploration of various support systems and phases for catalyst immobilization and recovery.

Main Results:

• Various strategies have been developed to facilitate catalyst separation and recycling.
• Biphasic systems, including solid/liquid and liquid/liquid, are effective for catalyst recovery.
• Insoluble inorganic supports, crosslinked polymeric supports, soluble polymeric supports, ionic liquids, and fluorous phases show promise.

Conclusions:

• Effective catalyst separation and recycling are crucial for the sustainable application of ruthenium and molybdenum catalysts.
• Biphasic systems offer versatile solutions for catalyst recovery in metathesis reactions.
• Continued development of novel supports and phases will enhance catalyst reusability and minimize environmental impact.