Liquid‐Liquid Biphasic, Platinum‐Catalyzed Hydrosilylation of Allyl Chloride with Trichlorosilane using an Ionic Liquid Catalyst Phase in a Continuous Loop Reactor

Abstract

Abstract:The platinum-catalyzed hydrosilylation of allyl chloride with trichlorosilane was investigated in an ionic liquid-organic biphasic reaction mode. After an ionic liquid screening and repetitive batch mode experiments, the process was realized in a continuous mode using a loop reactor concept with integrated continuous separation and recycling of the ionic liquid catalyst phase. The continuous reactor could be operated for 48 h at constant activity and selectivity without addition of platinum indicating that platinum leaching into the product phase was far below 1 ppm. Enhanced selectivity for the product trichloro(3-chloropropyl)silane (compared to the stateof-the art) and the possibility to use simple platinum tetrachloride (PtCl 4 ) as platinum source are further attractive features of this new ionic liquid-based process concept.

Ionic Liquids as Solvents for Rhodium and Platinum Catalysts Used in Hydrosilylation Reaction

“…As an anion for all ILs utilized during this study, bis(trifluoromethylsulfonyl)imide anion ([NTf 2 ] − ) was selected. [NTf 2 ] − anion is often used to form ILs known for their chemical inertness and hydrophobic properties and hence was most suitable for this study [22]. This second feature of [NTf 2 ] − is also crucial since water is often responsible for catalyst deactivation during hydrosilylation reactions.…”

“…Imidazolium and pyridinium based ILs have been selected as a most suitable group of ILs for investigation in hydrosilylation reaction due to a few major factors: (i) proved good solubility of many catalysts in ILs containing these cations; (ii) high chemical stability of imidazolium and pyridinium IL systems; (iii) proven high conversion rates of the reactions carried out using biphasic systems with catalysts being dissolved in IL phase; and (iv) often immiscibility of the reaction products in IL phase and lack of washing out of the catalyst from the IL phase [19,20,22]. Furthermore, those ILs are also one of the most commonly used ILs in organic synthesis [2], and they are relatively cheap and easy to handle and synthetize.…”

“…There have been several comprehensive papers regarding hydrosilylation reaction carried in the presence of ILs [19][20][21], but articles usually focus on a narrow scope of catalyst/IL systems, usually investigating in-depth one particular catalyst. As it is reported by Hoffman et al [22], most suitable for hydrosilylation reaction are salts with the [NTf 2 ] − anion. Thus, during our study, we have focused primarily on the investigation of various catalysts and their performance in different ILs, specifically containing [NTf 2 ] − anion, thus being able to investigate the influence of chemical modification of the cation on the catalyst activity.…”

Activation of Small Molecules by P-Ligand—Platinum Metal Complexes in Ionic Liquids

“…That is, the combination of high chemo-, regio-and enantioselectivities, attributed to several transition metal catalyzed homogeneous reactions, and the recyclability of ILs made these systems attractive towards green chemistry. Several recent general reviews on the efficacy of ionic liquids demonstrate their increasing role also in the field of electrochemistry [7,8], conventional organic [9][10][11][12], organometallic synthesis [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] and heterogeneous catalysis [28][29][30]. Interestingly, a steadily increasing importance of nanoparticle catalysis in ILs has also been observed.…”

Hydrosilylation reactions catalyzed by rhodium complexes with phosphine ligands functionalized with imidazolium salts

“…Hydrosilylation reactions of styrene with triethoxysilane.Reaction conditions: styrene 2.5 mmol; triethoxysilane 3.0 mmol; 90 C, 2 h; ligand/RhCl 3 : 1:5; BMimPF 6 : 0.5 mL. a 70 C, 5 h; Catalyst d: Tri[1-ethyl-2-diphenylphosphino-3-butylimidazolium hexafluorophosphate] rhodium chloride[13]. b Second run.…”