Spirobifluorene Synthesis for OLED Hole Transport
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
There is a demand for alternative materials and processes to synthesize spirobifluorene derivatives with larger groups in positions 1, 1′, 8, or 8′ for use in OLEDs, as existing methods face challenges in accessibility, high reaction yields, and purity, particularly for use in hole-transport or exciton-blocking layers.
Innovation Solution
A process involving metalation reactions, Suzuki couplings, and Buchwald-Hartwig amination is developed to prepare spirobifluorene derivatives with larger groups in positions 1, 1′, 8, or 8′, achieving high reaction yields and purity, and providing stable intermediate compounds for efficient OLED material synthesis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional synthesis methods are used to prepare spirobifluorene derivatives with larger groups in positions 1, 1′, 8 or 8′, then the compounds can be obtained for OLED use, but the reaction yields are low and the synthesis is difficult to implement
Solution Approach 1:
The synthesis is divided into multiple discrete steps: metalation of spirobifluorene, Suzuki coupling with boronic acid derivatives, and Buchwald-Hartwig amination. Each step is optimized independently to achieve high yields and facilitate purification of intermediates.
Solution Approach 2:
Stable intermediate compounds are isolated and purified after the metalation and Suzuki coupling steps. These intermediates serve as mediators that can be stored and used in subsequent amination reactions, simplifying the overall manufacturing process.
2Reliability
If spirobifluorene derivatives with larger groups are synthesized using existing processes, then the materials can be used in OLEDs, but the fabrication costs are high due to low reaction yields and difficult purification
Solution Approach 1:
The synthesis parameters are optimized at each step: metalation conditions (base, solvent, temperature), Suzuki coupling parameters (catalyst, base, solvent system), and amination conditions. These parameter optimizations lead to high reaction yields and facilitate easier purification, reducing overall fabrication costs.
Solution Approach 2:
The patent replaces difficult, low-yield conventional synthesis methods with a more efficient chemical approach using metalation and cross-coupling reactions. This substitution of synthesis methodology achieves both high OLED efficiency and cost-effective manufacturing.
3Productivity
If conventional hole-transport materials are used in OLEDs, then the devices can operate, but the efficiency is insufficient compared to spirobifluorene derivatives
Solution Approach 1:
The patent creates composite spirobifluorene structures by combining the spirobifluorene core with various aromatic amine groups through controlled substitution at positions 1, 1′, 8, or 8′. This composite approach maintains the beneficial properties of spirobifluorene while incorporating functional groups that enhance hole-transport efficiency in OLEDs.
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 process results in OLEDs with high efficiency and reduced fabrication costs, utilizing the synthesized spirobifluorene derivatives as hole-transport or exciton-blocking materials, and the intermediate compounds can be used in various OLED syntheses.
Implementation Method 1
process comprises the following steps: (a) Preparation of a compound of formula (Int-1) by a route (a-1) or by a route (a-2) as follows: Route (a-1): (a-1-1) Preparation of a compound of formula (p-3) by first a metalation reaction, preferably a lithiation reaction or a Grignard reaction
Implementation Method 2
followed by a cyclization reaction, preferably under acidic conditions or using a Lewis acid, between a fluorenone derivative of formula (p-2) with a compound of formula (p-1i): (a-1-2) Preparation of a compound of formula (Int-1) by a chemical reaction, preferably a Suzuki reaction
Implementation Method 3
Preparation of a compound of formula (1) by a chemical reaction, selected from amination reactions, more preferably from Buchwald-Hartwig amination reactions, between a compound of formula (Int-1) with a compound of formula (p-6)
Data Source
AI summary
The present invention relates to a process to produce compounds of the formula (1) which are suitable for use in electronic devices, as well as to intermediate compounds of formula (Int-1) and compounds of formula (1-1) and (1-2) obtained via the process. These compounds are particularly suitable for use organic electroluminescent devices. The present invention also relate to electronic devices, which comprise these compounds.