Hydrosilylation Selectivity with Nitrile and Aromatic Hydroxy Additives
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Solution Overview
Problem
Current hydrosilylation methods using hydrogenalkoxysilane compounds suffer from low reactivity and selectivity, particularly when dealing with olefin compounds containing tertiary amine atoms, leading to insufficient reaction yields and increased generation of side products due to double bond migration.
Innovation Solution
The method involves reacting an olefin compound with a hydrogensilyl group in the presence of a platinum catalyst, a nitrile compound, and an aromatic hydroxy compound to enhance reactivity and control double bond migration, thereby suppressing silylation at non-terminal carbon atoms and reducing by-product isomer formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydrogenalkoxysilane compound is used for hydrosilylation, then the procedure is more convenient and productivity is improved, but the hydrosilylation activity is inferior and selectivity of addition site is low
Solution Approach 1:
The patent introduces a carboxylic acid compound as an intermediary substance to mediate between the hydrogenalkoxysilane and the olefin. This mediator enhances the hydrosilylation activity and controls the addition site selectivity by facilitating the reaction mechanism, thereby resolving the contradiction between productivity and manufacturing precision.
Solution Approach 2:
The patent changes the chemical parameters of the reaction system by introducing carboxylic acid compounds with specific structural characteristics. This parameter change modifies the reaction pathway to achieve both high hydrosilylation activity and high selectivity for terminal carbon atom addition, overcoming the limitations of using hydrogenalkoxysilane alone.
2Power
If carboxylic acid compound is added to improve reactivity, then hydrosilylation activity increases, but side product generation from transesterification increases and control becomes difficult
Solution Approach 1:
The patent applies local quality by specifying particular structural characteristics for the carboxylic acid compound (such as aromatic carboxylic acids or carboxylic acids with specific substituent groups). This localized structural optimization enhances hydrosilylation activity while minimizing transesterification side reactions, thus increasing power without proportionally increasing harmful factors.
Solution Approach 2:
The patent optimizes the dynamic balance between desired reaction (hydrosilylation) and side reaction (transesterification) by carefully controlling the amount of carboxylic acid compound added. By maintaining the carboxylic acid compound at 0.01-2.0 equivalents relative to the olefin, the system dynamically achieves high activity while keeping side product generation可控.
3Ease of operation
If conventional methods are used with olefin compounds containing tertiary amine atoms, then reaction can proceed, but reactivity is insufficient due to catalyst poisoning
Solution Approach 1:
The patent converts the harmful effect of tertiary amine atoms (catalyst poisoning) into a manageable condition by using carboxylic acid compounds that can tolerate or even interact beneficially with amine groups. The carboxylic acid forms stable complexes with the platinum catalyst that resist deactivation by tertiary amines, thereby maintaining high reactivity despite the presence of catalyst poisons.
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 approach enables highly reactive hydrosilylation with high selectivity for terminal carbon atom silylation, maintaining reactivity while minimizing the formation of by-product isomers, even with olefin compounds that can act as catalyst poisons.
Implementation Method 1
reacting an olefin compound having a carbon-carbon unsaturated bond and a compound having a hydrogensilyl group by using a platinum catalyst
Data Source
AI summary
A hydrosilylation method is provided. In this hydrosilylation method, silylation of the carbon atom other than the terminal carbon atom and generation of the by-product isomer by internal migration of the double bond are suppressed without sacrificing the hydrosilylation reactivity, even if an olefin compound having tertiary amine atom which can be a catalyst poison was used. In the hydrosilylation, an olefin compound having carbon-carbon unsaturated bond, and a compound having hydrogensilyl group are reacted in the presence of a nitrile compound and an aromatic hydroxyl compound by using catalytic action of platinum and/or its complex compound.