CAAC Ruthenium Complexes for Oxygen-Tolerant Ethenolysis
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Solution Overview
Problem
The limited availability of structurally diverse aldehydes as substrates for synthesizing CAAC ligands, high prices, and complex synthesis pathways hinder the development of novel ruthenium catalysts with improved catalytic activity and stability for olefin metathesis reactions, particularly in ethenolysis processes, which are crucial for industrial applications involving unpurified vegetable oils and lower-purity ethylene.
Innovation Solution
Development of ruthenium complexes with CAAC ligands featuring heteroaromatic substituents that tolerate the presence of oxygen and lower-purity ethylene, allowing for robust and efficient ethenolysis processes without the need for extensive purification or inert atmospheres, enabling easy transport and storage under normal conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ruthenium complexes with NHC ligands are used, then catalytic activity in olefin metathesis reactions is achieved, but the complexes require strict inert atmospheres and pure substrates, increasing process complexity and cost
Solution Approach 1:
The patent changes the ligand type from NHC to CAAC (cyclic alkyl amino carbene), which fundamentally alters the catalyst's tolerance parameters. This ligand substitution enables the catalyst to function reliably with oxygen present and with lower-purity substrates, eliminating the need for strict inert atmospheres and extensive purification procedures while maintaining catalytic activity in olefin metathesis reactions
2Productivity
If structurally diverse aldehydes are used as substrates for synthesizing CAAC ligands, then novel catalysts with improved activity can be developed, but availability is limited and synthesis pathways are complex
Solution Approach 1:
The patent employs readily available and inexpensive aldehyde substrates (such as those derived from common aromatic compounds) as precursors for synthesizing CAAC ligands. These easily obtainable starting materials enable the production of diverse CAAC ligands through straightforward reactions, eliminating the need for rare or expensive substrates and simplifying the overall synthesis process while maintaining access to structurally varied catalysts
3Productivity
If high-purity ethylene and purified vegetable oils are used in ethenolysis reactions, then reaction efficiency is improved, but purification costs and time increase
Solution Approach 1:
The patent converts the previously harmful presence of oxygen and impurities in the reaction system into beneficial conditions. The CAAC-based ruthenium catalyst is specifically designed to tolerate oxygen and function effectively with lower-purity ethylene and vegetable oils. This tolerance allows the reaction to proceed efficiently without requiring extensive purification steps, time-consuming distillations, or complex purification apparatus, thereby reducing both time and cost while maintaining high reaction efficiency
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The new ruthenium complexes exhibit high catalytic activity and stability, facilitating efficient ethenolysis reactions with unpurified vegetable oils and lower-purity ethylene, making them suitable for large-scale industrial use without complex apparatus.
Implementation Method 1
The subject of the invention are novel ruthenium complexes with CAAC type ligands which have found a widespread use as catalysts and/or (pre)catalysts of olefin metathesis reactions
Data Source
AI summary
The object of the invention is a novel ruthenium complex of the general formula Ru-1, in which all the variable substituents have the meanings defined in the description. Also an object of the invention is a method for obtaining the ruthenium complex, a ligand precursor intermediate compound used in the preparation of the ruthenium complex CAAC-1 and the use of this ruthenium complex as a (pre)catalyst in olefin metathesis reactions.