Calixarene Catalysts for Low Metal Leaching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current metal catalysts face challenges in reducing residual metal levels in pharmaceutical products to below 10 ppm for oral administration and 1 ppm for parenteral administration, with heterogeneous catalysts having inferior performance compared to homogeneous catalysts and both experiencing metal leaching issues during reactions.
Innovation Solution
Development of a compound with the general formula (I) featuring calix[n]arene-based ligands that can function as either homogeneous or heterogeneous catalysts, specifically designed to minimize metal leaching and achieve low residual metal levels by using metal complexes with phosphorus ligands, N-heterocyclic carbenes, and salen ligands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If heterogeneous catalysts are used, then metal leaching is reduced, but catalytic performance deteriorates
Solution Approach 1:
The patent uses a soluble polymer support as an intermediary carrier to hold metal complexes, enabling the catalyst to function as a homogeneous catalyst in solution while allowing for easy separation through precipitation. This intermediary structure prevents direct metal leaching into the product while maintaining high catalytic activity.
Solution Approach 2:
The patent changes the physical state and solubility parameters of the catalyst by incorporating metal complexes into a soluble polymer matrix. This allows the catalyst to transition between dissolved and precipitated states, providing both high catalytic performance in solution and easy separation when needed, thereby resolving the contradiction between performance and metal leaching.
2Productivity
If homogeneous catalysts are used, then catalytic performance is improved, but metal leaching increases
Solution Approach 1:
The soluble polymer support acts as an intermediary that holds the metal complex, allowing it to function as a homogeneous catalyst with high performance while the polymer matrix prevents direct metal leaching into the reaction mixture and final product.
Solution Approach 2:
The patent creates a composite material consisting of metal complexes embedded in a soluble polymer matrix. This composite structure combines the high catalytic activity of homogeneous catalysts with the reduced metal leaching characteristics, enabling easy separation through precipitation while maintaining catalytic performance.
3Object-generated harmful factors
If metal deactivators are used, then residual metal levels are reduced, but manufacturing cost increases
Solution Approach 1:
The patent extracts the metal complex from the soluble polymer support through simple precipitation, achieving effective separation and removal of metal residues without requiring additional metal deactivators or complex purification steps, thereby reducing manufacturing costs while meeting residual metal specifications.
Solution Approach 2:
The soluble polymer support acts as a disposable carrier that can be easily separated and discarded with the precipitated catalyst, eliminating the need for expensive metal deactivators and complex purification processes, thus reducing manufacturing costs while achieving low residual metal levels.
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 solution provides high catalytic activity with reduced metal leaching, enabling the production of pharmaceutical products with metal residues below 100 ppm, and can be easily separated, addressing the limitations of existing catalysts.
Implementation Method 1
Mm+ is a metal in oxidation state m or a metal cluster comprising a plurality of metals in the oxidation state m, where m is 0, 1, 2, 3, 4 or 5, in particular 0, 1, 2 or 3, and L consists of one or more neutral ligands or negatively charged linked to the metal
Data Source
AI summary
The present invention relates to ligands based on calixarenes, metal complexes comprising such ligands and their use as homogeneous or heterogeneous catalysts.