Gold(I)-Catalyzed Chromane Synthesis from Biomass
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Solution Overview
Problem
Current synthetic pathways for tocopherols and tocotrienols often result in low yield and selectivity, and require corrosive conditions or the formation of unwanted side products, while also relying on non-renewable resources.
Innovation Solution
A new synthetic pathway using 2,5-dimethylfuran, obtained from biomass, reacts with specific alkyl groups in the presence of a gold(I) complex to form chromanes, such as β-tocopherol and β-tocotrienol, with high yield and selectivity, avoiding Friedel-Crafts alkylation and corrosive conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional synthetic pathways are used for tocopherols and tocotrienols, then the synthesis can be achieved, but the yield and selectivity are low and corrosive conditions are required
Solution Approach 1:
The patent changes the reaction parameters by using gold(I) catalysts instead of conventional Lewis acids, operating under milder conditions without requiring corrosive environments. This parameter change achieves both high yield/selectivity and eliminates harmful corrosive conditions simultaneously
Solution Approach 2:
The patent introduces gold(I) complexes as intermediary catalysts that mediate the cyclization reaction between alkynes and 2,5-dimethylfuran. This intermediary enables the reaction to proceed with high efficiency under mild, non-corrosive conditions, resolving the contradiction between productivity and harmful factors
2Ease of manufacture
If Friedel-Crafts alkylation is used, then chromanes can be synthesized, but substoichiometric Lewis-acidic salts are required which are redundant and corrosive
Solution Approach 1:
The patent extracts and eliminates the harmful Lewis-acidic salts from the conventional Friedel-Crafts alkylation pathway, replacing them with gold(I) catalysts that achieve the same chromane formation without generating corrosive conditions
Solution Approach 2:
The patent substitutes the mechanical/chemical mechanism of Lewis-acidic salt catalysis with gold(I) complex catalysis, which operates through a different mechanism that does not require corrosive conditions, thereby maintaining ease of manufacture while eliminating harmful factors
3Productivity
If conventional pathways are used, then tocopherols can be synthesized, but non-renewable resources are consumed with high environmental impact
Solution Approach 1:
The patent changes the resource base parameter by using 2,5-dimethylfuran derived from biomass (renewable) instead of conventional non-renewable petrochemical feedstocks, achieving sustainable synthesis without compromising productivity
Solution Approach 2:
The patent uses 2,5-dimethylfuran as a universal platform chemical that can be obtained from various biomass sources, enabling the synthesis pathway to function with renewable resources while maintaining high synthesis efficiency for tocopherols and tocotrienols
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
This process enables the efficient and sustainable synthesis of chromanes, including α-tocopherol and α-tocotrienol, with high yield and selectivity, using renewable biomass-derived materials and reducing environmental impact.
Implementation Method 1
the gold(I) complex [Au(I)OL]AN catalyses the intermolecular cyclization of furan with alkyne
Data Source
AI summary
The present invention relates to a method of preparing chromanes from 2,5-dimethylfuran and substituted alkynes comprising an long chain unsaturated alkyl group as substituent in the alpha position of a substituted phenol followed by oxidation, reduction and acid ring closure. It is particularly advantageous to use 2,5-dimethylfuran as this offers an ecological beneficial synthesis of β-tocopherol.