SiliaCat is the heterogeneous catalysts family from Silicycle. It is made by using an innovative technology that confers these materials advantageous properties for catalysis. SiliaCat is an organically modified silica made by a proprietary encapsulation process resulting in a new chemical matrix structure.
SiliaCat is a leach-proof organoceramic matrix with high catalyst loading and surface area that provides high turn over number (TON).
Advantages of using SiliaCat heterogeneous catalysts over competitive products include:
- High stability
- Rigid & Porous Structure (no swelling)
- Compatibility with a wide range of solvents
- Ease of use: no swelling or static charge
- High turnover number (TON)
- Fast kinetics
- Accurate loading
The SiliaCat Matrix
Inspired by the ORganically MOdified SILica (ORMOSIL) technology, the SiliaCat family is composed by new and innovative catalysts. Resulting from the co-condensation of two organosilane monomers by the sol-gel process (confer condensation mechanism below), the hybrid organic-inorganic materials present the highest stability and reactivity available with heterogeneous catalysts. Furthermore, the high cross linked framework presents an unmatched resistance, significantly better than the usual post-synthesis functionalized ligand.
|Product||Description / Typical Application|
|SiliaCat DPP-Pd Heterogeneous Catalyst (R390-100)||SiliaCat DPP-Pd is a unique diphenylphosphine palladium (II) heterogeneous catalysts made from a leach-resistant organoceramic matrix.|
Typical Application: Suzuki, Heck, Sonogashira, Kumada, Stille and Buchwald amination
|SiliaCat TEMPO Heterogeneous Catalysts (R723-100)||SiliaCat TEMPO is a heterogeneous catalyst/reagent made from a proprietary class of organosilica-entrapped radicals suitable for the selective oxidation of delicate substrates into valued carbonyl derivatives.|
Typical Procedure: Oxidation of alcohols or Aldehydes
|SiliaCat Pd0 Heterogeneous Catalysts (R815-100)||SiliaCat Pd0 is a new series of patent-protected sol-gel-entrapped Pd nanocatalysts. It is made from highly dispersed Pd nanoparticles (uniformly in the range 4.0-6.0 nm) encapsulated within an organosilica matrix.|
Typical Application: Suzuki, Heck Sonogashira, Kumada, Stille, Selective debenzylation, Selective hydrogenation
|SiliaCat Pt0 Heterogeneous Catalyst (R820-100)||SiliaCat Pt0 is made of organosilica physically doped with nanostructured Platinum(0), and is both stable and efficient.|
Typical Application: Selective reduction of nitroarenes, Hydrosilylation
Typical experimental procedures can be found for each catalytic reaction. Please note that these procedures are the starting suggestions meant to be starting points. Sometimes, optimization steps need to be undertaken to optimize yields and increase selectivity. Various parameters can be changed, one at a time or simultaneously, to improve results.
Number of mol % of SiliaCat Catalysts
For each new experiment, we suggest using a molar percent of SiliaCat with respect to the substrate. This quantity has to then be optimized in order to obtain a good catalytic activity with the lowest consumption of the SiliaCat. For initial experiments we suggest to use an higher mol % of SiliaCat Catalyst in respect to the substrate and then decrease the quantity if yield and kinetics are already in line with your needs. During development applications work at SiliCycle, we always start using 1 mol % of catalyst.
SiliaCat can safely be used in a wide range of organic and aqueous solvents commonly used in laboratory and in process work, such as DMF, DMSO, THF, ACN, alcohols, ethers, chlorinated solvents, water, etc. The nature of the solvent does sometimes influence the catalytic efficiency, however. If yield is low or kinetics are too slow, changing solvent or adding a co-solvent should be considered.
At low substrate concentration, the activity of the catalyst will be directly proportional to the number of moles of substrate available. If you increase the concentration of the substrate, the activity will increase until the active sites become saturated. So the substrate concentration is a parameter that needs to be optimized to develop your catalytic conditions.
A catalyst’s purpose is to enhance the kinetics of a reaction, so we recommend running the experiments at room temperature. In the optimization step, the temperature could be adjusted, if it is needed.
In the case that the TOF is low, and increasing the temperature to increase the kinetics is not possible, we recommend increasing the contact time with the catalyst to complete the reaction. Also, in this case, increasing of the amount of catalyst is an option.