Stereoregular ROMP Polymers via Cyclobutene Monomers
Solution Overview
Problem
Ring opening metathesis polymerization (ROMP) with cyclic unsaturated amides is unpredictable, particularly when regiochemistry and geometry of the resulting double bond cannot be predicted, making it difficult to correlate physical or biological properties with specific structural features.
Innovation Solution
Development of stereoregular ROMP polymers using monomers with specific structural constraints, such as formula 1, which are polymerized using functional group-tolerant ruthenium catalysts to produce translationally invariant, all head-to-tail and E-olefinic polymers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If ruthenium-catalyzed polymerization is used on 5-substituted norbornene and oxanorbornene monomers, then functional group tolerance is improved, but stereochemical control deteriorates
Solution Approach 1:
The patent changes the monomer structure from 5-substituted norbornene to 1-substituted cyclobutene, fundamentally altering the substrate parameters. This structural parameter change enables both functional group tolerance and stereochemical control to be achieved simultaneously, as the cyclobutene ring opens to give predictable head-to-tail connectivity and E-olefinic geometry while accommodating various functional groups.
Solution Approach 2:
The patent extracts the problematic stereochemical variables from the system by removing the norbornene bicyclic structure and using simple cyclobutene instead. This eliminates the three uncontrolled stereochemical variables that plagued norbornene polymerization, leaving only the desired functional group tolerance property.
2Adaptability or versatility
If ROMP is conducted with cyclic unsaturated amides containing conjugated double bonds, then monomer versatility is improved, but predictability of regiochemistry and geometry deteriorates
Solution Approach 1:
The patent changes the monomer class from cyclic unsaturated amides with conjugated double bonds to cyclobutene carboxylic acid amides with isolated double bonds. This parameter change in the position and nature of the double bond provides predictable regiochemistry (head-to-tail) and geometry (E-olefinic) while maintaining the ability to polymerize various amide-functionalized monomers.
3Ease of manufacture
If norbornene derivatives are used for ROMP polymerization, then synthetic accessibility is improved, but stereochemical uniformity deteriorates
Solution Approach 1:
The patent extracts the stereochemical complexity from the norbornene bicyclic framework and replaces it with simple cyclobutene structures. This removal of the problematic structural feature eliminates the source of stereochemical heterogeneity while preserving synthetic accessibility through straightforward monomer preparation methods.
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 approach results in polymers with predictable and controlled stereochemistry, allowing for correlation of physical and biological properties with structural features, enhancing the synthesis of materials with desired properties.
Implementation Method 1
ring opening metathesis polymerization (ROMP) has been broadly applied for the synthesis of materials with interesting physical properties
Implementation Method 2
functional group-tolerant ruthenium catalysts to produce translationally invariant, all head-to-tail and E-olefinic polymers
Data Source
AI summary
The invention relates to stereoregular ROMP polymers, the monomers used to make them, and the processes used to convert the monomers to the polymers.