Nickel-Amine-Phosphine Catalyst for Suzuki Coupling
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Solution Overview
Problem
Current catalysts for Suzuki coupling reactions, such as palladium-phosphine and nickel-amine catalysts, face issues with high costs, instability, and poor handling properties, leading to inefficient cross-coupling reactions, especially when using less expensive raw materials.
Innovation Solution
A catalyst composition comprising a complex of a nickel salt with an amine compound and triphenylphosphine, specifically formulated to enhance the activity and efficiency of cross-coupling reactions, including Suzuki coupling reactions, by using a nickel salt, a tertiary bidentate amine compound, and triphenylphosphine in a controlled ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a palladium-phosphine catalyst is used for Suzuki coupling reaction, then the reaction proceeds at a desired rate, but the catalyst is expensive
Solution Approach 1:
The patent replaces expensive palladium catalysts with cheaper nickel-based catalysts that can be used in stoichiometric or near-stoichiometric amounts. The nickel catalyst system, while potentially less stable individually, achieves practical stability and effectiveness through the synergistic combination of nickel salt, amine compound, and phosphine ligand, making it economically viable for large-scale production
Solution Approach 2:
The patent creates a composite catalytic system by combining nickel salt, amine compound, and phosphine ligand in specific ratios. This composite approach allows each component to compensate for the weaknesses of others: nickel provides cost-effectiveness, amine enhances stability and reactivity, and phosphine provides catalytic activity, collectively achieving both low cost and high productivity
2Quantity of substance
If a nickel-phosphine catalyst is used as a substitute for palladium, then the cost is reduced, but the phosphine ligand is expensive and has poor stability and handling properties
Solution Approach 1:
The patent optimizes the molar ratios of nickel salt to amine compound to phosphine ligand, establishing specific ranges (Ni:amine = 1:1 to 1:10, Ni:phosphine = 1:1 to 1:5) that maximize catalyst stability and activity. This parameter optimization ensures that the phosphine ligand is used in sufficient quantity to stabilize the nickel center while maintaining cost-effectiveness and improving handling properties through enhanced catalyst robustness
3Productivity
If bis(1,5-cyclooctadiene)nickel is used as the nickel compound, then the catalyst shows activity, but it is very sensitive to air and difficult to handle
Solution Approach 1:
The patent introduces amine compounds as intermediary stabilizing agents that coordinate to the nickel center, creating a more air-stable catalyst complex. The amine acts as a protective ligand that reduces the sensitivity of nickel to oxidation by air, allowing the catalyst to be handled under less stringent conditions while maintaining its catalytic activity for the Suzuki coupling reaction
4Productivity
If a strong base such as potassium phosphate is used with nickel catalyst, then the reaction proceeds, but the base is expensive and causes decomposition of boronic acid
Solution Approach 1:
The patent modifies the base parameters by using milder bases such as carbonates, bicarbonates, or hydroxides instead of strong bases like potassium phosphate. This parameter change in base strength and pH reduces the decomposition of boronic acid substrates while the optimized nickel-amine-phosphine catalyst system compensates by maintaining sufficient reaction efficiency under these milder conditions
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 catalyst composition achieves high yields and efficiency in producing cross-coupled compounds, even with less expensive base materials, and is more stable and cost-effective compared to previous catalysts, making it suitable for commercial use.
Implementation Method 1
a catalyst composition comprising a complex of a nickel salt with an amine compound, and triphenylphosphine
Implementation Method 2
a technique utilizing a coupling reaction wherein a boron-containing compound is allowed to react with an organic halide compound in the presence of a base and a catalyst
Data Source
AI summary
A catalyst composition for a cross-coupling reaction comprising a nickel salt-amine complex of formula (1), and triphenylphosphine.where R1 thru R4 independently represent alkyl, aryl, heteroaryl or alkenyl; n is an integer of 1-6; and X independently represents halo, hydroxyl, nitrate or acetate group. Using the catalyst composition, a cross-coupling reaction is carried out between a boron-containing compound of formula (2) and a compound of formula (3).where R5 and R6 are the same as R1-R4 defined above; Y independently represents hydroxyl or alkoxy, Z is halo, methanesulfonate or trifluoromethanesulfonate.